Tags

RP2350 and ESP32-C6 support, RISC-V native emitter, common TinyUSB code

This release of MicroPython adds support for the new RP2350 MCU, improved
RISC-V support with native code generation, support for ESP32-C6 MCUs,
update Zephyr version with threading support, unified TinyUSB bindings
across ports, a portable UART IRQ API, and enhanced mpremote recursive
copy.  There are also numerous bug fixes, enhancements to the test suite
and more attention to testing of the machine module and its API.  Read on
for more details.

Support for the RISC-V architecture has been significantly extended, to
include an RV32IMC native code emitter, native NLR and GC register scanning
implementations for 32- and 64-bit RISC-V, support for placing RV32IMC native
code in .mpy files and also freezing it, and RISC-V semihosting support.
Testing for RISC-V is done with the qemu and unix ports, and the support is
utilised in the esp32 and rp2 ports.

There is now support concatenation of adjacent f-strings, as well as raw
f-strings.  There is also a new `micropython.RingIO` class which provides a
stream interface to an efficient, thread-safe, byte-oriented ring-buffer
implementation.

All the ports that use TinyUSB have now been unified to use the same shared
helper code for CDC serial.  This includes: esp32 (S2 and S3), mimxrt,
renesas-ra, rp2 and samd ports.  With this has come the useful feature that
the startup CDC serial data is buffered and then sent to the host upon
connection.  This means that (among other things) the REPL banner and
initial prompt is now seen on first connection to a board.

Most ports now support registering Python callbacks for UART IRQs, and the
semantics for the callback are made as consistent as possible across the
ports.  The possible IRQs are IRQ_RX, IRQ_RXIDLE, IRQ_TXIDLE and IRQ_BREAK,
and the ports that have added support for these are esp32, mimxrt, nrf,
renesas-ra, rp2 and samd (stm32 already had this feature).

In the networking sub-system, a new API for configuring IP addresses and
related settings has been added: the global `network.ipconfig()` function,
and a `nic.ipconfig()` method on individual network interfaces.  This new
API supports both IPv4 and IPv6, with much more control compared to the
original `nic.ifconfig()` method; the latter is still available for
backwards compatibility, but `ipconfig()` is now preferred moving forward.

A portable `network.PPP` implementation has been added, based on lwIP.
This is not enabled by default but can be added to custom boards that
use bare-metal lwIP.

The `machine.SoftSPI` class now supports least-significant-bit (LSB) mode,
as well as the existing MSB mode.

The behaviour of `sys.exit()` and `raise SystemExit` (which are equivalent)
has been changed: previously this would terminate the running script and
drop to the REPL, but now it terminates the running script and triggers a
soft reset of the device.  This is more consistent with the unix port,
which exits completely on a `SystemExit` exception.  This change in
behaviour is a breaking change and may impact certain applications; see
commit 69c25ea8653566ec97690b5121bd10b753c89426 for details.

The mpremote tool has a new hashing ability, eg `mpremote sha256sum <file>`
and also has enhanced recursive copy which first checks the hash and only
updates the destination file if the hash is different.  This makes copying
a large directory to a device significantly faster, and enables a "sync"
workflow, where small changes can be made to a large application and then
quickly deployed to the device via the recursive copy.

The esp32 port now supports ESP-IDF v5.2.2, and with this comes support for
ESP32-C6 MCUs.  The RISC-V native emitter has been enabled on C3 and C6
MCUs.  There have also been some important bug fixes, for handling of
native code loaded from .mpy files, fixes for stack corruption, and a fix
to I2S, among other things.  Also, applications that use many TCP sockets
in quick succession should see an improvement because there is now a hard
limit on the number of active TCP sockets.

The qemu port has been renamed from qemu-arm to simply qemu, and now
supports both ARM and RISC-V architectures.  It has also been reworked to
provide a REPL and to run tests via a pty serial port, emulating how tests
are run on bare-metal targets.

The rp2 port has updated pico-sdk to v2.0.0, which brings support to
MicroPython for the new RP2350 MCU, in both ARM and RISC-V mode, and in
both the 30- and 48-pin variants.  IPv6 has been enabled by default on this
port, and optional `network.PPP` made available.  The USB now remains
active during `machine.lightsleep()`, and there have been many bug fixes.

The stm32 port also sees optional `network.PPP` support through lwIP, and
support for octospi on STM32H7 MCUs.  A build option has been added to put
IRQ, flash and UART code in RAM, and this feature is enabled on boards with
a UART REPL, to allow filesystem access to work on these boards without
losing UART characters (eg when using mpremote to copy files to a board).
Preemptive keyboard interrupt via PendSV has been removed: this was buggy
and no longer necessary; see ece950d9bed18554e945188c5a31908c8bfa9a7b for
details.  The ARDUINO_PORTENTA_H7 and ARDUINO_NICLA_VISION boards have
added support for the NXP SE05x secure element, with integration in
mbedTLS.

The webassembly port has better asyncio support, including the ability to
do a top-level await of `Task` and `Event` objects.  There has also been
enhancements to the proxying of objects between JavaScript and Python.

The zephyr port has updated to use Zephyr v3.7.0, threading has been
implemented through the `_thread` module, the REPL now operates in
non-blocking mode so it can process events/callbacks, some more Python
features including big-integers have been enabled, and machine objects (eg
Pin, I2C) can now be constructed using device-tree node labels.

New boards added in this release are: ESP32_GENERIC_C6,
M5STACK_ATOMS3_LITE, M5STACK_NANOC6, OLIMEX_ESP32_EVB, UM_FEATHERS3NEO,
UM_OMGS3, UM_RGBTOUCH_MINI and UM_TINYC6 (esp32 port), RPI_PICO2 (rp2
port), ARDUINO_OPTA (stm32 port).

The change in code size since the previous release for various ports is
(absolute and percentage change in the text section):

       bare-arm:   +116  +0.203%
    minimal x86:   +185  +0.100%
       unix x64:  +8994  +1.098%
          stm32:  +1028  +0.263%
         cc3200:  +1152  +0.625%
        esp8266:  +2968  +0.426%
          esp32: -53617  -3.101%
         mimxrt:  +1864  +0.513%
     renesas-ra:  +1536  +0.245%
            nrf:  +1460  +0.781%
            rp2:  +3592  +1.068%
           samd:  +2244  +0.845%

The leading causes of these changes in code size are:
- bare-arm, minimal: fix `int.to_bytes()` buffer size checks
- unix: enable GCM and ECDHE-RSA in mbedTLS config
- stm32: add new `RingIO` class
- cc3200: add `network.ipconfig` and `WLAN.ipconfig`
- esp8266: add `network.ipconfig`, `WLAN.ipconfig` and `RingIO` class
- esp32: update ESP-IDF from v5.0.5 to v5.2.2
- mimxrt, renesas-ra, nrf, rp2, samd: `RingIO` class and `UART.irq` support

Performance is effectively unchanged since the previous release on all
ports, except the unix port which sees some reduction in GC times due to
no more root-pointer scanning of executable memory.

Thanks to everyone who contributed to this release: Adrian Higgins,
Alessandro Gatti, Alexandre Iooss, Amirreza Hamzavi, Andrea Milazzo, Andrew
Leech, Angus Gratton, Ayush Singh, cajt, Christian Walther, Corran Webster,
Damien George, Dan Halbert, danicampora, David Lechner, dmfaria, Dryw Wade,
Elvis Pfützenreuter, Felix Dörre, George Hopkins, Glenn Moloney,
iabdalkader, IhorNehrutsa, Jared Hancock, Jason Kridner, Jim Mussared, Jon
Foster, Jos Verlinde, Junwha, Laurens Valk, Lennart, Leo Chung, Matt
Trentini, Matthias Blankertz, Maureen Helm, Michael Sawyer, Michael
Vornovitsky, nspsck, Owen, Paul Grayson, Peter Harper, Peter Züger, Phil
Howard, Plaque FCC, Rick Sorensen, robert-hh, Seon Rozenblum, shiggy,
stijn, Sylvain Zimmer, Takeo Takahashi, Terence Stenvold, tharuka, Tim
Weber, timdechant, Volodymyr Shymanskyy, Yoctopuce, ZodiusInfuser.

MicroPython is a global Open Source project, and contributions were made
from the following timezones: -0700, -0600, -0500, -0400, -0300, +0000,
+0100, +0200, +0300, +0330, +0530, +0800, +0900, +1000, +1100.

The work done in this release was funded in part through GitHub Sponsors,
and in part by George Robotics, Espressif, Anaconda, Arduino, LEGO
Education, OpenMV and Planet Innovation.

What follows is a detailed list of changes, generated from the git commit
history, and organised into sections.

Main components
===============

py core:
- nlrrv32: add RISC-V RV32I NLR implementation
- lexer: support concatenation of adjacent f-strings
- lexer: support raw f-strings
- objdeque: fix deque type flags based on option settings
- asmrv32: add RISC-V RV32IMC native code emitter
- emitnative: emit better load/store sequences for RISC-V RV32IMC
- emitnative: add more DEBUG_printf statements
- emitndebug: add native debug emitter
- emitnative: place thrown value in dedicated local variable
- emitnative: fix native async with
- misc: move mp_clz and mp_ctz intrinsics into misc.h
- objint: fix int.to_bytes() buffer size checks
- objarray: fix buffer overflow in case of memory allocation failure
- asmrv32: make some code sequences smaller
- objint: try to convert big-int back to small-int after binary op
- asmrv32: do not use binary literals
- objstr: add new mp_obj_new_str_from_cstr() helper function
- remove 5 TODOs in emitbc, objrange and repl
- lexer: add static assert that token enum values all fit in a byte
- sequence: remove unused len argument from mp_seq_extract_slice
- gc: remove commented-out functions
- objtype: avoid crash on calling members of uninitialized native type
- objtype: validate super() arguments
- misc: fix msvc and C++ compatibility
- runtime: fix self arg passed to classmethod when accessed via super
- py.mk: add SRC_USERMOD_LIB_ASM to include assembly files
- emitnative: fix case of clobbered REG_TEMP0 when loading const obj
- modmath: add option to work around -inf bug in a port's tgamma
- obj: remove the legacy object API for version 2
- add new cstack API for stack checking, with limit margin macro
- objstr: skip whitespace in bytes.fromhex()
- asmrv32: fix short/long jumps scheduling
- asmrv32: emit C.LW opcodes only when necessary
- asmrv32: use REG_TEMP2 whenever possible
- mkrules.mk: fix 'make submodules' when building out-of-tree
- objint: make byteorder argument optional in int.to_bytes() method
- objint: make length argument optional in int.to_bytes() method
- objint: make byteorder argument optional in int.from_bytes() method
- scheduler: only run callbacks on the main thread if GIL is disabled
- objringio: add micropython.RingIO() interface for general use
- persistentcode: explicitly track native BSS/rodata when needed
- mpz: skip separators when running out of digits to print
- parse: remove old esp32 compiler workaround
- nlrrv64: add RISC-V RV64I NLR implementation
- objtype: allow passing keyword arguments to native base __init__
- usermod.cmake: check target exists in usermod_gather_sources
- objtype: don't delegate lookup of descriptor methods to __getattr__

extmod:
- network_ninaw10: implement the ipconfig methods for ninaw10
- network_lwip: allow using the CIDR notation for addr4
- modlwip: make socket.connect raise ETIMEDOUT on non-zero timeout
- modlwip: consolidate socket.accept timeout logic
- modplatform: add picolibc to the recognised libcs list
- modasyncio: add support for a callback on TaskQueue push
- extmod.mk: disable maybe-uninitialized warnings in libm_dbl
- machine_usb_device: add USBDevice.remote_wakeup method
- mbedtls: enable GCM and ECDHE-RSA in common mbedtls config
- modmachine: allow more than one argument to machine.freq()
- network_nina: fix the AP security mode constants
- machine_spi: support firstbit=LSB for machine.SoftSPI
- modre: rename re_exec to re_exec_helper to avoid clash on BSD
- modmachine: use sys.exit as implementation of machine.soft_reset
- modos: include os.sep entry if MICROPY_VFS is enabled
- modbtree: add checks for already-closed database
- moductypes: validate the descriptor tuple
- vfs_fat: set default volume label on mkfs if it's defined
- vfs: fix buffer overflow of string comparison in umount
- libmetal: remove source file listed twice in sources
- modopenamp_remoteproc: fix entry point address int overflow
- modopenamp: add support for building Open-AMP on device side
- modopenamp: fix Endpoint callback required arg
- modopenamp: use mp_event_* functions for poll/wait
- modtls_mbedtls: fix DER parsing and calculation of key/cert len
- modtls_mbedtls: optimise the DER certificate parsing fix
- network_wiznet5k: add support for IPv6
- update make and cmake scripts to work with latest lwIP
- network_ppp_lwip: add network.PPP via lwIP
- modlwip: fix compile error for lwIP with SLIP support
- libmetal: fix libmetal rules for mkdir dependencies
- vfs_blockdev: check block device function positive results
- vfs_blockdev: implement common helper for read and write
- vfs_posix_file: skip flush of tty handles in msvc debug builds
- modframebuf: fix FrameBuffer size check for stride corner-cases
- network_wiznet5k: reset mDNS when interface is brought up
- modtls_mbedtls: add a thread-global ptr for current SSL context
- modtls_mbedtls: support alternate sign callbacks in Python

shared:
- tinyusb: add common CDC TX/RX functions
- tinyusb: allow ports to use 1200bps-touch without other CDC code
- tinyusb: buffer startup CDC data to send to host on connection
- runtime/gchelper: add RISC-V RV32I native gchelper
- runtime/semihosting: rename ARM semihosting files
- runtime/semihosting: add RISC-V semihosting support
- tinyusb/mp_usbd_runtime: fix pointer comparison in assert
- tinyusb/mp_usbd_cdc: fix short CDC TX timeouts
- tinyusb/mp_usbd_cdc: skip writing to an uninitialized USB device
- runtime/pyexec: make a raised SystemExit always do a forced exit
- runtime/gchelper: add RISC-V RV64I native gchelper
- tinyusb: allow ports to define CDC TX/RX buffer sizes
- runtime/semihosting_arm: support semihosting on non-Thumb ARM
- runtime/semihosting_arm: add mp_semihosting_rx_chars
- runtime/semihosting_arm: add mp_semihosting_exit
- runtime/sys_stdio_mphal: fix printed type for stdio streams
- tinyusb: only run TinyUSB on the main thread if GIL is disabled
- tinyusb: use new persistent-tx-fifo configure interface
- runtime/gchelper_rv64i: fix opcode sw/sd typo
- tinyusb: remove MICROPY_HW_USB_EXTERNAL_TINYUSB
- tinyusb: wake main task if needed at end of USB ISR
- timeutils: document the range of year/month/day etc input values

drivers: no changes specific to this component/port

mpy-cross:
- add RISC-V RV32IMC support in MPY files
- main: use MICROPY_BANNER_NAME_AND_VERSION for --version

lib:
- remove tinytest component
- libm: do not force floating point type size evaluation
- tinyusb: update to the most recent master
- libm: define _IEEE_LIBM only if not set
- arduino-lib: update submodule to the latest
- lwip: update lwIP to STABLE-2_2_0_RELEASE
- libffi: update libffi to 3.4.6
- tinyusb: update to version 0.17.0
- pico-sdk: update to version 2.0.0
- arduino-lib: update submodule
- micropython-lib: update submodule to latest

Support components
==================

docs:
- rp2/quickref: document the use of channel numbers for ADC
- update docs to replace ifconfig with ipconfig
- specify that machine.idle() returns at least every 1ms
- library/neopixel: mention bitstream timing tuple
- mimxrt/quickref: add a note about machine.RTC() subseconds
- library/machine.UART: fix UART.irq docs to match current code
- library/machine.UART: extend the documentation for UART.irq
- library: document the network.PPP class
- esp32: update pin access example with addresses for ESP32-S3
- reference: fix pyboard.py filesystem cp example with three files
- library: document math.log with two arguments
- library: document machine.Pin.toggle() method
- zephyr: update docs to reflect device name changes
- reference/mpremote: update docs to mention new features

examples:
- usercmodule/cexample: add more advanced native class
- network: support IPv4 and IPv6 in HTTP client examples
- network: use SSLContext instead of old ssl.wrap_socket
- network: support full URLs in HTTP(S) client examples
- natmod: fix URL links in README.md

tests:
- cpydiff: remove deque difference test
- thread: re-enable GC before stress_schedule test ends
- basics: add tests to test repeated throw into the same generator
- thread/stress_aes.py: fix logic waiting for finished threads
- stress/bytecode_limit.py: make test more robust with low memory
- extmod: make get_event_loop tests compatible with CPython 3.12
- multi_bluetooth/perf_gatt_notify.py: reduce connection interval
- run-tests.py: enable thread tests on esp32
- cpydiff: add diff for overriding __init__
- run-tests.py: make Windows test skipping more granular
- multi_net: fix skipping of SSLContext tests when .der don't exist
- extmod: skip soft machine.Timer test on esp32 port
- extmod: add esp32 support to the machine_i2s_rate test
- extmod: rename machine_timer exp file to machine_soft_timer
- extmod: add machine_spi_rate test
- extmod/ssl_keycert.py: add test for PKCS8 formatted DER key
- run-tests.py: enable stress tests on esp32 port
- run-tests.py: skip additional tests when slice unavailable
- extmod: add test for machine.UART.IRQ_TXIDLE
- extmod_hardware: add tests for machine.UART.IRQ_RX/RXIDLE/BREAK
- basics: add tests for optional args to int.to_bytes/from_bytes
- net_inet: update micropython.org certificate for SSL tests
- run-tests.py: automatically detect native arch and mpy-cross flag
- extmod/machine_uart_irq_txidle.py: simplify the test script
- thread: adapt stress_aes.py to run on zephyr
- run-tests.py: add a zephyr test target
- run-tests.py: remove --write-exp and --list-tests options
- ports/unix: update and extend the modffi integer tests
- README: update instructions for key/cert pair usage on device
- tweak machine SPI and UART tests to work with esp32c6
- run-tests.py: wait for soft reset if a target skips a test
- ports/rp2: update DMA test to work on RP2350
- ports/rp2: add simple rp2-specific UART test
- ports/rp2: update lightsleep/machine_idle to skip on RP2350
- run-tests.py: only run inlineasm tests on rp2 ARM targets
- extmod: config SPI test for esp8266 and skip SoftTimer test
- extmod: adjust ssl/tls tests to run on targets with axTLS
- micropython: tweak ringio test for targets with terse errors
- run-tests.py: skip large viper test on esp8266
- extmod: make invalid-blockdev test work consistently on all ports
- extmod: support esp32,mimxrt,stm32,samd ports in UART TX test
- extmod: add a simple test for machine.RTC
- extmod: fix access of RTC class in machine.RTC test
- extmod: use time_ns instead of time in lfs mtime test
- extmod: add test to compare time_ns with time
- extmod: fix machine_spi_rate test on ESP32-C3

tools:
- metrics.py: change rp2 board selection to RPI_PICO_W
- makemanifest.py: generate working code for empty manifests
- mpremote: fix absolute path usage in remote mounted VFS
- ci.sh: build an stm32 board with -O2 enabled
- mpy-tool.py: implement freezing of long-long ints
- mpremote: fix mpremote mip install with multiple lib in sys.path
- pyboard.py: capture stdout for pts line
- mpy-tool.py: support freezing rv32imc native code
- mpy_ld.py: ignore R_XTENSA_ASM_EXPAND relocation entries
- ci.sh: clean up the Unix port's MIPS target
- ci.sh: add missing FFI helper for CI RV64 Unix builds
- ci.sh: clean up the Unix port's Arm target
- mpy_ld.py: support jumping more than 2k on armv6m architectures
- ci.sh: let RV64 use a source-built version of libffi
- metrics.py: add VIRT_RV32 to the code size metrics
- ci.sh: report code size for `VIRT_RV32` as well
- ci.sh: upgrade Zephyr docker image 0.26.13 and SDK 0.16.8
- mpremote: make eval parse by default
- mpremote: make filesystem commands use transport API
- mpremote: add hashing ability and use for recursive copy
- mpremote: improve error output
- mpremote: add initial regression tests for mpremote
- mpremote: add option to force copy
- only issue a single Ctrl-C when entering raw REPL
- ci.sh: add RPI_PICO2 to CI

CI:
- ISSUE_TEMPLATE: update issue form to remove checklist generation
- add Pull Request template
- workflows: use macos-latest for unix macos CI
- workflows: improve MSYS2-based CI builds
- workflows: add RISC-V 64 bits Unix port to CI
- workflows: add CI to run tests against zephyr with qemu
- workflows: update Ubuntu images for code size CI tasks
- workflows: free up disk space on zephyr workflow

The ports
=========

all ports:
- fix lwIP config setting to disable DHCP ARP check
- include py/mphal.h instead of mphalport.h

bare-arm port: no changes specific to this component/port

cc3200 port:
- mods: implement network.ipconfig and network.WLAN.ipconfig
- mods/pybuart: add the UART.IRQ_RX class constant

embed port: no changes specific to this component/port

esp8266 port:
- network_wlan: implement network.ipconfig and WLAN.ipconfig
- rework board variant support to require mpconfigvariant file
- use new mp_obj_new_str_from_cstr() function

esp32 port:
- implement ipconfig() for more network interfaces
- network_ppp: implement network.PPP.ipconfig method
- rework board variant support to require mpconfigvariant file
- use new mp_obj_new_str_from_cstr() function
- mpthreadport: fix uneven GIL allocation between Python threads
- machine_timer: limit timer numbers for ESP32C3
- mpconfigport: enable the RV32 emitter for ESP32C3 targets
- fix heap corruption triggered by bluetooth.active(0)
- machine_i2s: ensure 2 DMA buffers and improve I2S error handling
- enable workaround for math.gamma(-inf) result
- main: store native code as linked list instead of list on GC heap
- network_lan: make LAN.active(state) succeed if already in state
- network_lan: ensure LAN MAC address is valid at LAN init
- fix thread stack limit margin, change to new cstack API
- adc: add support for v5.2.1 calibration api
- boards: reduce IRAM usage
- adc: use new ADC calibration API in all cases
- boards: build using newlib nano formatting functions
- tools: add metrics_esp32 size comparison script
- add support for ESP-IDF v5.2.2
- use the ESP-IDF default esp_console config for ESP32-C3
- restore ESP32-C3 brownout detector settings to IDF defaults
- boards: remove BLE from list of features for ESP32-S2
- mphalport: print debug strings even before the GIL is ready
- fix Python cstack size for bluetooth irq callbacks
- remove the increased stack limit margin for ESP32-C3
- boards/M5STACK_ATOMS3_LITE: add M5Stack AtomS3 Lite board
- boards/LILYGO_TTGO_LORA32: add OLED rst seq for board v1.0
- boards: remove all IDF3 variants
- machine_uart: implement Python UART IRQ with IRQ_RX and IRQ_BREAK
- machine_uart: implement UART.RX_IDLE based on machine.Timer
- fix ESP32-C3 USB serial/jtag peripheral pre-IDF 5.1
- add MICROPY_HW_USB_CDC macro for native USB-CDC serial
- fix ARDUINO_NANO_ESP32 build configuration
- disable hardware stack protection on ESP32-C3
- boards/UM_FEATHERS3NEO: add FeatherS3 Neo board definition
- boards: add UM_OMGS3 and UM_RGBTOUCH_MINI board definitions
- boards/OLIMEX_ESP32_EVB: add Olimex ESP32 EVB board definition
- boards/UM_RGBTOUCH_MINI: fix compile error with missing modules
- use shared/tinyusb integration for S2 and S3 USB
- add automatic bootloader handling for S2 and S3
- Makefile: allow auto-port selection if not passed on cmdline
- boards: update ARDUINO_NANO_ESP32 USB configuration
- add support for esp32c6
- machine_adc: make ADC 2 optional
- machine_timer: generalise timer clock configuration
- modesp32: make gpio_deep_sleep_hold optional
- machine_uart: add support for LP_UART
- adc: set ADC to 12bit by default on esp32c6
- Makefile: only set port & baud for jobs that access hardware
- boards/ESP32_GENERIC_C6: add new generic esp32c6 board
- boards/M5STACK_NANOC6: add new M5Stack C6 board definition
- boards/UM_TINYC6: add new UM C6 board definition
- sdkconfig: disable PMP_IDRAM_SPLIT to fix native emit support
- fix hang in taskYIELD() on riscv CPUs when IRQs disabled
- apply the LWIP active TCP socket limit
- disable hardware stack protection on ESP32-C6
- mphalport: always poll stdin ring-buffer to include UART use
- modmachine: allow building with USB CDC disabled

mimxrt port:
- mphalport: refactor to use shared TinyUSB CDC functions
- implement ipconfig() for more network interfaces
- mpmetalport: use mp_event_handle_nowait() for metal_poll
- mimxrt_sdram: fix pin config and comments
- machine_pin: clear IRQ flag when enabling or disabling IRQ
- machine_uart: implement a Python UART IRQ handler

minimal port: no changes specific to this component/port

nrf port:
- consolidate all stdio functions
- modules/machine/uart: support sending data stored in flash
- Makefile: enable LTO by default only on newer gcc
- modules/machine/soft_pwm: ensure duty_width is always valid
- modules/machine/pin: disable IRQ with pin.irq(handler=None)
- Makefile: fix GCC_VERSION check
- modules/machine/uart: allow changing the UART baud rate w/o reset
- modules/machine/uart: implement Python UART IRQ for nrf52840 boards

pic16bit port: no changes specific to this component/port

powerpc port: no changes specific to this component/port

qemu port:
- add license and copyright to files missing them
- clean up header file includes
- fix tinytest test profile when updating set of dirs/files
- Makefile: make the build directory reflect the board
- uart: implement uart_rx_chr
- rework to provide a REPL and run tests via a pty serial port
- factor board config to mk fragments
- Makefile: clean up SRC and OBJ variables
- merge RISC-V 32-bit support into qemu-arm port
- enable RISC-V native code generation by default
- rename qemu-arm port to qemu
- mcu/rv32: fix test of mcause value in lookup_cause

renesas-ra port:
- mphalport: refactor to use shared TinyUSB CDC functions
- machine_uart: add the UART.IRQ_RX class constant
- machine_uart: implement UART.IRQ_RXIDLE based on softtimer
- README: add basic details about board autogen files
- boards: add configuration.xml for auto-generated files
- extint: fix issue with Pin.irq not triggering
- usb: use interrupt rather than polling for USB task
- pendsv: remove preemptive keyboard interrupt via PendSV

rp2 port:
- refactor soft timer to use hardware timer alarm
- refactor to not use pico-sdk alarm pool functions for sleeping
- support calling pendsv_suspend/resume from core 1
- mphalport: refactor to use shared TinyUSB CDC functions
- modmachine: use atomic section macros in lightsleep code
- modmachine: selectively leave the USB clocks enabled in lightsleep
- CMakeLists: use MICROPY_BOARD_DIR to find pins.csv
- cyw43_configport: make cyw43_delay_ms() a busy loop
- fix recursive atomic sections when core1 is active
- clocks_extra: implement custom clocks_init function
- fix USB PLL glitch during wake from light sleep
- don't disable USB if going to DORMANT mode
- pendsv: fix variable typo in assert so it compiles
- rework board variant support to require mpconfigvariant file
- boards/WEACTSTUDIO: fix variant names in board.json
- replace CMSIS funcs with Pico SDK equivalents
- mbedtls: remove config options that are now in the common settings
- rp2_pio: replace PIO_NUM macro with pio_get_index
- rp2_pio: replace explicit pio ternary expression with pio_get_index
- machine_adc: initialise ADC GPIO when a Pin is referenced by int
- fix power consumption when sleeping with a timeout
- fix wakeup from WFE on core1
- rp2_pio: disable correct IRQ for PIO1
- stop machine.idle() blocking indefinitely
- lwip_inc: enable IPv6 per default on rp2 port
- CMakeLists.txt: add MICROPY_DEF_BOARD to compile definitions
- boards/PIMORONI_PICOLIPO: refactor Pico LiPo to use board variants
- boards/PIMORONI_TINY2040: add an 8MB variant to Tiny 2040
- memmap_mp.ld: lower the minimum GC heap to 32K
- rp2_pio: make PIO IRQ handlers have lazy initialisation
- machine_i2s: deinit all active I2S instances on soft reset
- switch to use new cstack API for stack limit checks
- mphalport: skip core1_entry if thread disabled
- main: set the default clock frequency at boot
- modmachine: set the peripheral frequency with machine.freq()
- machine_uart: implement a Python UART IRQ handler
- integrate optional network.PPP
- add board-level hooks to main, and MICROPY_SOURCE_BOARD cmake var
- increase ext pins from 10 to 32
- machine_pin_cyw43: include check for CYW43_GPIO
- modules: fix FatFS boot script to detect invalid FAT filesystem
- machine_uart: fix dropped UART REPL bytes on soft reset
- cyw43_configport: define CYW43_PRINTF to mp_printf to get messages
- mpconfigport: set MCU name for RP2350
- update custom linker scripts for new pico-sdk
- modmachine: implement lightsleep for RP2350
- rp2_dma: generalise DMA for RP2350
- integrate RP2350 and use aon_timer instead of rtc API
- add support for 48-pin RP2350 variant
- machine_pin: move decl of machine_pin_obj_table to public header
- rp2_pio: add support for RP2350A/B variants in PIO interface
- boards/make-pins.py: pass num-gpios/num-ext-gpios into make-pins
- machine_pin: use 64-bit gpio functions to allow gpios >=32 to work
- machine_pin: generalise gpio_irq handler for pins >32
- clocks_extra: update runtime_clocks_init based on new pico-sdk
- machine_adc: add ADC support for RP2350B
- add support for RP2350 in RISCV mode
- Makefile: allow CMAKE_ARGS to be set by user
- machine_bitstream: set SysTick reset value
- machine_uart: allow new TX/RX pins on RP2350
- mphalport: implement mp_hal_ticks_cpu for RISCV using mcycle
- machine_bitstream: implement bitstream for RISC-V using mcycle
- workaround pico_aon_timer timezone binary size increase
- machine_pwm: add RP2350 slices to machine.PWM
- main: set CPU frequency to default for the MCU
- boards/RPI_PICO2: add new RPI_PICO2 board definition
- machine_uart: clear timeout_char when UART is first constructed
- machine_uart: make it so TX is done only when no longer busy
- mpconfigport: leave callable pointers alone on RV32
- datetime_patch: fix year and month offset for mktime wrapper
- modmachine: re-sync time_ns offset when coming out of lightsleep

samd port:
- mphalport: refactor to use shared TinyUSB CDC functions
- boards/ADAFRUIT_METRO_M4_EXPRESS: remove wlan variant
- mcu/samd21: allow user to enable additional options
- machine_uart: implement a Python UART IRQ handler
- machine_uart: implement UART.IRQ_RXIDLE based on the softtimer
- mphalport: fix an execution order bug in mp_hal_ticks_us_64()
- mphalport: simplify mp_hal_delay_ms()
- Makefile: specify UF2 family in firmware.uf2

stm32 port:
- implement ipconfig() for more network interfaces
- pin: decrease machine_pin_obj_t.pin width from 5 to 4 bits
- rework board variant support to require mpconfigvariant file
- boards: swap FMC banks on ARDUINO_GIGA and ARDUINO_PORTENTA_H7
- mpu: define the last used MPU region number
- mpmetalport: use mp_event_handle_nowait() for metal_poll
- boards: add missing images and update product URLs
- stm32_it: enable PVD_PVM_IRQHandler for WB and WL MCUs
- rfcore: allow HSE to be a wakeup source for BLE for the WB55
- octospi: add OSPI support for STM32H7 MCUs
- system_stm32: allow selection of OSPI clock source
- boards/STM32H7B3I_DK: fix octo-spi pin configuration
- machine_uart: add the UART.IRQ_RX event for UART.irq()
- integrate optional network.PPP
- machine_uart: allow changing only the baudrate
- machine_uart: return number of bytes written even with timeout
- uart: use timeout_char even with CTS enabled
- lwip_inc: implement LWIP_PLATFORM_DIAG macro in terms of printf
- add option to put ISR, flash and UART code in RAM
- boards: enable RAM_ISR feature on boards with UART REPL
- update STM32L452xx Multi OTG handling
- boards/STM32F429DISC: add DAC support to the STM32F429DISC
- uart: add UART RX/CTS pin pull config options
- powerctrl: add pre/post stop mode entry macros
- boards/ARDUINO_OPTA: add support for the Arduino Opta board
- boards/ARDUINO_PORTENTA_H7: update board config files
- boards/ARDUINO_NICLA_VISION: update board config files
- boards/ARDUINO_GIGA: update board config files
- pendsv: remove preemptive keyboard interrupt via PendSV
- Revert "stm32: - machine_uart: allow changing only the baudrate."
- boards/ARDUINO_PORTENTA_H7: add SE05x driver
- boards/ARDUINO_NICLA_VISION: add SE05x driver
- boards/ARDUINO_OPTA: add Opta expansion module

unix port:
- modtermios: add more baudrate options
- mpbthciport: remove thread detached attribute
- mpbtstackport_usb: remove thread detached attribute
- main: fix GCC builds for RISC-V 64 bits
- switch stack limit check to new cstack API
- coveragecpp: include all API headers in the C++ code
- expand the build steps in the README
- add a description of COPT in the README
- README: fix typo in build dependencies
- modffi: fix signed integer cast in return_ffi_value
- modffi: clean up FFI closures memory management
- modffi: restrict uint32_t values to 32 bits
- alloc: don't trace executable memory for GC pointers
- alloc: remove unused MICROPY_FORCE_PLAT_ALLOC_EXEC option
- main: add --version command-line option

webassembly port:
- objjsproxy: implement proxying of JS iterable protocol
- asyncio: support top-level await of asyncio Task and Event
- asyncio: schedule run loop when tasks are pushed to queue
- api: allow specifying the pystack size
- objjsproxy: lookup attributes without testing they exist
- reuse PyProxy objects when they are the same Python object

windows port: no changes specific to this component/port

zephyr port:
- modzsensor: add additional sensor type constants
- modsocket: add socket.recvfrom method
- link MicroPython with the Zephyr kernel library
- remove obsolete tinytest test framework
- increase CONFIG_CONSOLE_GETCHAR_BUFSIZE to 258
- add threading support
- re-implement the Zephyr console in non-blocking mode
- enable some core features to get more thread tests passing
- main: collect registers during a MicroPython GC scan
- mpconfigport: enable mpz big integers
- Kconfig: increase default GC heap size to 48k
- src: remove k_yield() at the end of console_irq_input_hook()
- mphalport: make mp_hal_wait_sem() always call k_poll()
- update include paths to use the zephyr namespace
- replace zephyr.h with kernel.h
- replace deprecated FLASH_AREA macros with FIXED_PARTITION
- change main function to return an int
- change SPI chip select from a pointer to a struct member
- upgrade to Zephyr v3.7.0
- refactor device lookup into a common helper function
- allow using devicetree node labels to construct machine objects
- boards: add support for BeagleConnect Freedom

Dynamic USB devices, revamped webassembly port, openamp, tls, vfs modules

This release of MicroPython adds support for dynamic USB devices defined in
Python, adds new `openamp`, `tls` and `vfs` modules, completely revamps the
webassembly port to add proxying between JavaScript and Python, and
implements significant code size optimisations for frozen modules.  There
are also many other enhancements and bug fixes.  Keep reading for a more
detailed summary of the main changes.

After a lot of design, development and testing, MicroPython now has full
support for user-defined USB devices.  The interface is via a new
`machine.USBDevice` class, and this allows the user to specify the USB
descriptors and implement Python callbacks for USB endpoint transfers.
With this, any USB device can be implemented in pure Python.  While the
`machine.USBDevice` interface is low-level and complete, there is a
higher-level USB library in `micropython-lib` that allows easier
implementation of devices, with examples for keyboard, mouse, MIDI and
serial CDC.  This feature is currently available on rp2 and samd ports, and
other ports will follow in the future.

Support for the OpenAMP (asymmetric multiprocessing) protocol has been
added through the new `openamp` module.  This allows MicroPython to control
other CPU cores in the system, to load and start processes and communicate
with them through endpoints.  This feature is currently available on the
mimxrt and stm32 ports.

Two other new modules have been added: `vfs` and `tls`.  The `vfs` module
contains all VFS (virtual filesystem) related functions and classes, such
as `mount`, `umount` and `VfsFat`.  These were originally in the `os`
module but having them there is not compatible with CPython, so they have
been moved to their own dedicated module.  They still exist in the `os`
module for now but will eventually be removed from there, so it's
recommended to start using the `vfs` module from now on.  Similarly the new
`tls` module is an evolution of the `ssl` module, whereby all the existing
functionality in `ssl` has been moved to the `tls` module.  This is done
because MicroPython's SSL interface is becoming increasingly different to
CPython's and moving this SSL/TLS functionality to a new `tls` module gives
it room to grow and obtain new features that are useful for embedded
applications.  And compatibility with normal Python is still retained via a
pure Python implementation of the `ssl` module.  One new feature in the new
`tls` module is the ability to register a certificate verification
callback.

Other additions include more methods on the `deque` object so it is
doubly-ended and supports iteration, and support for half-float 'e' format
in `struct.pack`/`struct.unpack`.  Dynamic native modules have had some
additional runtime methods exposed, and the .mpy sub-version has been
increased from v6.2 to v6.3 (native code in .mpy files will need to be
recompiled, but bytecode does not and is still compatible).

There has also been significant code size optimisations for frozen modules.
A new internal `mp_proto_fun_t` type has been defined which allows the
common case of bytecode functions (as opposed to native code) to be stored
in frozen code without any additional overhead of the `mp_raw_code_t`
descriptor structure.  All firmware builds using frozen modules will see a
significant decrease in size.  Code size has also improved further for very
small targets by adding an option to remove the qstr hash bytes.

Internally in the source code the "STATIC" macro definition has been
removed.  Code should now just use "static" instead.  If you have C/C++
code that uses "STATIC" then either replace it with "static", or provide
your own #define to define "STATIC" as "static".  See commit
decf8e6a8bb940d5829ca3296790631fcece7b21 for details.

Mbedtls has been updated to version 3.5.1.  And network interface
constants, such as `IF_STA` and `SEC_WPA2`, have now been consolidated
across ports so they all live at the `WLAN` class level, for example
`network.WLAN.SEC_WPA2` (existing constants at the `network` module level
have been retained for backwards compatibility, but the new ones should be
preferred from now on).

The esp32 port has seen some important bug fixes in the BLE component, to
deinitialise without crashing, and increase the BLE task stack size.  This
port also uses the new I2S IDF driver, and supports IDF 5.0.5 and 5.2.
There is support to enter the bootloader via `machine.bootloader()` and a
new `esp32.mcu_temperature()`, for ESP32-C3/S2/S3 devices.

The rp2 port has added the new `machine.USBDevice` dynamic USB driver, and
has had firmware performance optimisations applied to critical parts of the
runtime and VM, giving about a 10% performance boost.  There is now direct
memory access to PIO and SPI FIFOs via proxy arrays, and bugs have been
fixed with threads, lightsleep and UART IRQ latency.

The stm32 port has integrated support for the new `openamp` module, which
is enabled on all Arduino boards.  And firmware for Arduino boards now
freeze in additional Arduino-specific library code.  There have been fixes
for internal flash writes on STM32H5 and STM32H7 MCUs (bank selection and
flashing of the last word in a buffer), an important fix to a SPI DMA
caching bug, an I2C clock enable fix for I2C4 on STM32F7 MCUs, and a fix
for the FDCAN source clock frequency on STM32G4 MCUs.  Mboot has added
support for a new raw filesystem, to allow simpler and more robust firmware
updates.

The webassembly port has seen a significant overhaul in its structure, and
is now built as a JavaScript .mjs module that exports a user-friendly
JavaScript-level API which is inspired by the API provided by Pyodide
(which is a version of CPython that runs in the browser).  This change is
motivated by the need to use MicroPython as an engine within Pyscript,
which is a platform for Python in the browser.  New features in the
webassembly port include proxying of objects between Python and JavaScript,
a `js` module to interface with the JavaScript namespace, a `jsffi` module
for miscellaneous proxy helpers, top-level async code, JavaScript driven
asyncio support, automatic growing of the Python heap, integration of
JavaScript and Python finalisation for global memory management, more
`time` module functions, and support for build variants (following the unix
port).

The change in code size since the previous release for various ports is
(absolute and percentage change in the text section):

       bare-arm:   -220  -0.383%
    minimal x86:   -341  -0.184%
       unix x64: +20168  +2.527%
          stm32:  -1692  -0.430%
         cc3200:   +256  +0.139%
        esp8266:  -8880  -1.260%
          esp32:  -3328  -0.194%
         mimxrt:   -408  -0.112%
     renesas-ra:   -464  -0.074%
            nrf:   -640  -0.341%
            rp2:  +5380  +1.626%
           samd:  +3224  +1.229%

The leading causes of these changes in code size are:
- bare-arm, minimal: disabling qstr hashing
- unix: updating mbedtls to version 3.5.1
- stm32: optimising size of frozen modules
- cc3200: addition of new `vfs` module, and bug fixes in the VM and array
  type
- esp8266: disabling unused `MICROPY_DEBUG_PRINTERS` and optimising frozen
  modules
- esp32, mimxrt, renesas-ra, nrf: optimising frozen modules
- rp2: addition of `machine.USBDevice`, enabling -O2 optimisations
- samd: addition of `machine.USBDevice`

Performance is effectively unchanged since the previous release on all
ports, except the rp2 port which sees a performance improvement of roughly
10%.

Thanks to everyone who contributed to this release: Amirreza Hamzavi,
Andrew Leech, Angus Gratton, Brian Pugh, Carlosgg, Christian Walther,
Damien George, Daniël van de Giessen, darc, Dash Peters, David Lechner,
Felix Dörre, iabdalkader, IhorNehrutsa, Iksas, J. Neuschäfer, Jared
Hancock, Jim Lipsey, Jim Mussared, Jochen Sprickerhof, Joey232, Jos
Verlinde, Kwabena W. Agyeman, Maarten van der Schrieck, Matt Trentini,
Matthias Urlichs, Michiel W. Beijen, MikeTeachman, Nicko van Someren,
Olivier Lenoir, Phil Howard, Rick Sorensen, robert-hh, Sebastian Romero,
Simon Wood, Stanislav Ponomarev, stijn, Takeo Takahashi, Trent Piepho,
Trent Warlaven, Vonasmic, YAMAMOTO Takashi, Yoctopuce.

MicroPython is a global Open Source project, and contributions were made
from the following timezones: -0800, -0700, -0600, -0500, -0300, +0000,
+0100, +0200, +0330, +0400, +0900, +1000, +1100.

The work done in this release was funded in part through GitHub Sponsors,
and in part by George Robotics, Espressif, Anaconda, Arduino, LEGO
Education, OpenMV and Planet Innovation.

What follows is a detailed list of all changes, generated from the git
commit history, and organised into sections.

Main components
===============

all:
- fix "reuse" and "overridden" spelling mistakes
- update bindings, ports and tests for mbedtls v3.5.1
- use mp_obj_malloc_with_finaliser everywhere it's applicable
- remove the "STATIC" macro and just use "static" instead
- prune trailing whitespace
- update extmod, ports, examples to build with new berkeley-db lib
- add pre-commit hook for codespell
- update copyright year range to include 2024
- ISSUE_TEMPLATE: convert issue templates to forms

py core:
- py.mk: remove extra build dir created for frozen_content
- qstr: add support for MICROPY_QSTR_BYTES_IN_HASH=0
- mpconfig: disable qstr hashing at minimum feature level
- builtinimport: simplify calls to stat_path()
- compile: fix potential Py-stack overflow in try-finally with return
- emitglue: reorder and resize members of mp_raw_code_t
- emitglue: provide a truncated mp_raw_code_t for non-asm code
- emitglue: simplify mp_raw_code_t's kind and scope_flags members
- emitglue: introduce mp_proto_fun_t as a more general mp_raw_code_t
- emitglue: include fun_data_len in mp_raw_code_t only when saving
- makeversionhdr.py: reinstate MICROPY_GIT_HASH in mpversion.h
- obj: change sizeof to offsetof in mp_obj_malloc_var macro
- obj: introduce mp_obj_malloc_with_finaliser to allocate and set type
- misc: remove m_new_obj[_var]_with_finaliser macros
- objfun: make mp_obj_new_fun_native/mp_obj_new_fun_asm static-inline
- objfun: split viper fun type out to separate mp_type_fun_viper type
- emitnative: simplify layout and loading of native function prelude
- objfun: support __name__ on native functions and generators
- objfun: inline mp_obj_code_get_name() into mp_obj_fun_get_name()
- emitglue: remove n_pos_args from DEBUG_printf
- builtinevex: fix setting globals for native functions in compile()
- compile: remove TODO about name mangling
- emitglue: make mp_emit_glue_assign_native's fun_data arg a const ptr
- mpconfig: change the default enable level for the vfs module
- emitbc: remove call to adjust Python stack by 0 entries
- mpstate: don't declare mp_thread_get_state()
- modthread: move thread state initialisation to shared function
- emitglue: add explicit cast of proto_fun to uint8_t pointer
- objstr: add a macro to define a bytes object at compile time
- stream: add mp_stream_seek() helper function
- stream: factor stream implementations
- objdeque: expand implementation to be doubly-ended and support iter
- asm: add ASM_NOT_REG and ASM_NEG_REG macros for unary ops
- asmxtensa: optimise asm_xtensa_mov_reg_i32_optimised() for tiny ints
- emitnative: implement viper unary ops positive, negative and invert
- binary: support half-float 'e' format in struct pack/unpack
- parse: zero out dangling parse tree pointer to fix potential GC leak
- compile: add option to allow compiling top-level await
- nlr: add "memory" to asm clobbers list in nlr_jump
- makeqstrdata.py: ensure that scope names get low qstr values
- dynruntime: add mp_binary_get_size/get_val_array/set_val_array
- persistentcode: bump .mpy sub-version to 6.3
- objfun: fix C++ compatibility with casting in inline functions
- obj: fix initialiser order in MP_DEFINE_CONST_OBJ_TYPE_NARGS_ macros
- objarray: fix use-after-free if extending a bytearray from itself
- nlrthumb: make non-Thumb2 long-jump workaround opt-in
- dynruntime: add mp_obj_exception_init function to create C exception
- dynruntime: export mp_load_method_maybe and mp_arg_parse_all* funcs

extmod:
- extmod.mk: disable uninitialized warnings in kf_rem_pio2.c
- asyncio: support gather of tasks that finish early
- modssl_mbedtls: fix cipher iteration in SSLContext.get_ciphers
- modssl_axtls: add SSLContext.load_cert_chain()
- modtls: move the native ssl module to tls
- modtls_mbedtls: implement cert verification callback for mbedtls
- modvfs: add new "vfs" module with mount/umount and Vfs classes
- btstack: reset pending_value_handle before calling write-done cb
- btstack: reset pending_value_handle before calling read-done cb
- modrandom: add integer type casts where appropriate
- modlwip: support IPv6
- network_wiznet5k: adjust IP types for IPv6
- vfs_posix_file: ensure file object has safe default fd
- modmachine: remove MICROPY_PY_MACHINE guard from header
- modwebsocket: fix websocket to send correct close frame
- modlwip: add back support for empty IP addresses
- asyncio: make current_task raise exception when there is no task
- nimble: override configuration options set in nimble_port_init
- nimble: enable key distribution to support bonding
- network_ninaw10: activate the NIC on demand
- network_ninaw10: set the proper security mode if none provided
- network_ninaw10: fix error messages
- modmachine: add MICROPY_PY_MACHINE_SIGNAL configuration option
- modmachine: add MICROPY_PY_MACHINE_MEMX configuration option
- modmachine: add MICROPY_PY_MACHINE_RESET configuration option
- nimble: check for active before setting address mode
- machine_usb_device: add support for Python USB devices
- libmetal: add MicroPython platform for libmetal
- modopenamp: add new OpenAMP module
- modopenamp_remoteproc: add new OpenAMP RemoteProc class
- os_dupterm: handle exception properly when it occurs in parallel
- modnetwork: implement IPv6 API to set and get NIC configuration
- network_wiznet5k: properly enable interrupt signal on w5100s
- add interface and security constants at WLAN class level
- modtls_axtls: add verify_mode and CERT_NONE constant
- modopenamp: set a default log handler for ports
- modopenamp: use metal logging functions exclusively
- modasyncio: make mp_asyncio_context variable public
- network_wiznet5k: properly enable socket buffers for W5100(S)
- modlwip: use Nagle algorithm and add support for TCP_NODELAY
- modos: only sync FAT filesystems using disk_ioctl

shared:
- timeutils: remove useless void-return
- tinyusb: don't disconnect on soft reset unless USB was active
- tinyusb: update some code comments for runtime USB
- tinyusb: increase default string descr max length to 40 chars
- tinyusb: fix dynamic USB control callbacks for wLength==0
- tinyusb: stall the CDC IN endpoint while disconnecting

drivers:
- dht: only build DHT driver if MICROPY_PY_MACHINE_PULSE enabled
- memory: add IS25LPWP064D chip to list of external flash devices

mpy-cross: no changes specific to this component/port

lib:
- cmsis: update to CMSIS 5.9.0
- mbedtls: update to mbedtls v3.5.1
- mbedtls_errors: update error list for latest mbedtls
- micropython-lib: update submodule to latest
- cyw43-driver: update driver to latest version v1.0.3
- open-amp: add OpenAMP submodule
- libmetal: add libmetal submodule
- berkeley-db-1.xx: update submodule URL and version
- arduino-lib: add Arduino's external library

Support components
==================

docs:
- samd/pinout: update pinout docs with fixed pin assignment
- develop/porting: fix argument type of mp_lexer_new_from_file()
- add note about position-only arguments in CPython vs MicroPython
- library/ssl: change wrap_socket args keyfile/certfile to key/cert
- library: move vfs functions and classes from os to vfs module docs
- reference/micropython2_migration.rst: add info about os and vfs
- use vfs module instead of os
- library/sys.rst: document implementation.version.releaselevel
- library/bluetooth: add note that ESP32 supports pairing/bonding
- library/openamp: document the new openamp module
- library/collections: update deque docs to describe new features
- library/rp2.DMA: add documentation for rp2 DMA support
- library/machine.RTC: add docs for RTC.memory() method
- reference/mpyfiles: document change in .mpy sub-version
- develop/optimizations: fix typo identified in issue 14391
- esp32/quickref: add note about different ESP32 varieties
- library/machine.USBDevice: update note about packages in mp-lib
- reference: document how to mip install packages from GitLab
- library/asyncio: document that ThreadSafeFlag now works on unix
- update copyright year range to include 2024

examples:
- embedding: add -fno-common to the sample compiler flags
- natmod/framebuf: enable FrameBuffer.poly method
- usb: add a very simple USBDevice example with host
- usb: add a USBDevice example implementing the DFU protocol
- network: rename SSL examples to start with https
- network: add example of HTTPS client using non-blocking socket
- usb: add README that points out the alternative usb modules
- natmod/features4: create custom FactorialError as exc example
- natmod/btree: make btree.open use mp_arg_parse_all for kwargs

tests:
- run-tests.py: remove machine_mem.py test from skip list
- thread: adjust thread tests so most are able to run on rp2 port
- thread: add a test for accuracy of sleep within a thread
- run-multitests.py: change to dir of test script when running it
- multi_net: generate smaller certs with 2048-bit RSA
- run-tests.py: add an option for running only the failed tests
- run-tests.py: remove unneeded argument from run_feature_check()
- run-tests.py: make repl test detection more correct
- run-tests.py: fix path-based special test detection
- extmod/machine_uart_tx.py: add a test for timing of UART.flush()
- move port-specific test directories into tests/ports/ directory
- ports/rp2: add rp2-specific tests with a test for rp2.DMA
- extmod/machine_i2s_rate.py: test multiple I2S instances
- extmod/asyncio_wait_task.py: add test for raise and delayed wait
- extmod: remove asyncio .exp files that match CPython output
- extmod/framebuf_polygon.py: replace sys.stdout.write with print
- ports/rp2/rp2_dma.py: tweak test to be more reliable
- use vfs module instead of os
- multi_bluetooth/ble_irq_calls.py: enhance test to test recursion
- ports/unix: add coverage test for frozen functions and generators
- cpydiff: add new CPy diff test for class name mangling
- multi_bluetooth: move ble_deepsleep to stress_deepsleep_reconnect
- basics: split MicroPython-specific deque tests to separate file
- float/float_struct_e.py: add specific test for struct 'e' type
- run-tests.py: support running webassembly tests via node
- ports/webassembly: add webassembly JS tests
- net_inet: add simpler tls sites test, and skip existing on axtls
- cpydiff: add a note about risk of resizing memoryview targets
- micropython/import_mpy_invalid.py: skip if target cant import mpy
- run-natmodtests.py: fix search for supported native tests
- extmod: fix regex strings to be of r"" type
- extmod: add .exp test files for asyncio.get_event_loop tests
- basics: split out generator.throw tests that pass multiple args
- net_hosted/ssl_verify_callback.py: make exp match actual output
- net_inet/tls_text_errors.py: tweak test for newer CPython version
- float: use "not" instead of ~ to invert bool value
- basics: add .exp file for slice_op test
- basics: move str/bytes tests that give SyntaxWarning to sep file

tools:
- gen-changelog.sh: exclude "-preview" tags from generated log
- mpremote: reduce dependency on importlib_metadata
- manifestfile.py: change library search to use a list of paths
- mpy-tool.py: fix static qstrs when freezing without qstr header
- mpy-tool.py: skip generating frozen mp_raw_code_t when possible
- manifestfile.py: add --unix-ffi option
- ci.sh: add Arduino GIGA to stm32 CI build
- mpy-tool.py: fix merging of more than 128 mpy files
- ci.sh: update webassembly CI tests
- manifestfile.py: fix freeze() when script is an empty iterable
- mpremote: add support to mip install from GitLab
- ci.sh: simplify selection of natmod tests to run

CI:
- workflows: bump actions/cache from 3 to 4
- workflows: run mimxrt and rp2 CI with space in repository path
- workflows: move Windows CI from AppVeyor to GitHub Actions
- workflows: bump setup-msbuild, setup-python, checkout versions
- workflows: initialise micropython-lib submodule for windows CI
- workflows: move codespell to a GitHub workflow, version it
- workflows: add comments where tool versions need to be in sync
- workflows: standardise formatting of ruff.yml
- workflows: add Biome workflow for JavaScript formatting/linting
- workflows: update coverage workflow to codecov-action@v4
- workflows: run code size workflow on shared or port code changes

The ports
=========

all ports:
- move MICROPY_PY_LWIP_ENTER/REENTER/EXIT defns to mphalport.h
- move MICROPY_INTERNAL_WFE definition to mphalport.h
- fix handling of paths containing spaces in Makefiles
- add LED pin aliases for all Arduino boards
- use vfs module instead of os
- on cold boot, enable USB after boot.py completes
- don't include mpthread.h in mpthreadport.h

bare-arm port: no changes specific to this component/port

cc3200 port: no changes specific to this component/port

embed port:
- fix alloca include for FreeBSD and NetBSD
- improve stack top estimation

esp8266 port:
- boards/ESP8266_GENERIC: disable MICROPY_DEBUG_PRINTERS
- Makefile: add support for C++ user C modules
- network_wlan: add interface and security WLAN constants

esp32 port:
- modsocket: use all supplied arguments to socket.getaddrinfo()
- boards/UM_FEATHERS3: use read_uv() for accurate battery voltage
- network_ppp: make PPP support optional
- mpnimbleport: release the GIL while doing NimBLE port deinit
- increase NimBLE task stack size and overflow detection headroom
- machine_i2c: fix build warnings when I2C is disabled
- machine_hw_spi: combine argument parsing for constructor and init
- boards: add missing named digital pins for Arduino Nano ESP32
- machine_i2s: integrate new I2S IDF driver
- add support for IDF version v5.0.5
- add support for IDF version v5.2
- add IDF-version-specific sdkconfig
- mpconfigport: don't hang when machine.bootloader isn't supported
- modmachine: support bootloader on ESP32-S2/S3/C2/C3
- network_lan: add a separate argument to set PHY power pin
- machine_uart: always configure timeout_char setting in init()
- boards/ESP32_GENERIC_S3: add 4MiB partitioning board variant
- workaround IDF issue placing ISR ringbuf functions in IRAM
- main: check if main GC heap allocation failed
- network_wlan: add interface and security WLAN constants
- modesp32: add mcu_temperature() function for C3/S2/S3 devices
- panichandler: print support information on panic
- add support for TCP_NODELAY

mimxrt port:
- mphalport: remove redundant NVIC/IRQ defines
- mpbthciport: add missing extmod/modmachine.h header
- boards: fix __VECTOR_TABLE link issue with CMSIS 5.9.0
- modmachine: fix deepsleep wakeup pin ifdef
- fix header include guard names
- mpconfigport: enable cryptolib and hashlib md5
- define the MICROPY_HW_ENABLE_USBDEV macro
- set the security mode for the default WiFi AP
- add support for OpenAMP

minimal port:
- allow compiling on macOS
- use printf instead of echo -e

nrf port:
- modules/os/microbitfs: sweep the filesystem if any free chunk found
- fix _start() build issue with CMSIS 5.9.0
- boards: add named pins for Arduino Nano 33 BLE
- boards: enable MICROPY_HW_ENABLE_USBDEV on boards with USB CDC
- Makefile: allow external board definitions
- modules/machine: enable code formatting
- fix non-running LFCLK
- modules/machine: catch exceptions from pin interrupts
- modules/machine/pwm: tag a PWM device as used in the constructor
- main: fix build of microbit when SD is enabled
- Makefile: clean up dangling LIBS declaration
- mpconfigport: enable MICROPY_NLR_THUMB_USE_LONG_JUMP on nRF51xx

pic16bit port: no changes specific to this component/port

powerpc port: no changes specific to this component/port

qemu-arm port:
- mpconfigport: use MICROPY_CONFIG_ROM_LEVEL_EXTRA_FEATURES

renesas-ra port:
- ra: fix SysTick clock source
- ra: remove unnecessary min_delay() declaration
- boards/ARDUINO_PORTENTA_C33: fix the RTC clock source
- ra/ra_i2c: fix 1 byte and 2 bytes read issue
- fix spelling mistakes found by codespell
- boards: add named pins for Arduino Portenta C33
- boards/ARDUINO_PORTENTA_C33: add Arduino's external library

rp2 port:
- rp2_flash: lockout second core only when doing flash erase/write
- mutex_extra: implement additional mutex functions
- mpthreadport: fix race with IRQ when entering atomic section
- rp2_dma: fix fetching 'write' buffers for writing not reading
- provide direct memory access to PIO and SPI FIFOs via proxy arrays
- machine_uart: fix event wait in uart.flush() and uart.read()
- mpconfigport: allow MICROPY_PY_THREAD to be disabled by a board
- mpthreadport: make result of thread.get_ident() a non-zero integer
- machine_uart: fix potential race condition in interrupt handling
- boards/ARDUINO_NANO_RP2040_CONNECT: increase flash storage space
- change machine.I2S and rp2.DMA to use shared DMA IRQ handlers
- boards: add named digital pins for Arduino Nano RP2040 Connect
- enable support for Python USB devices
- CMakeLists: apply O2 optimisation to map, mpz and vm source code
- modmachine: prevent lock-up when lightsleep() called within thread
- README: fix typo, improve sentence about building with other boards
- boards/W5500_EVB_PICO: update incorrect url in board.json

samd port:
- remove the MICROPY_PY_MACHINE_RTC config option
- mcu/samd21: reorganize and enable more firmware features
- mcu: fix wrong EIC table entries in pin-af-table.csv
- mpconfigport: simplify and consolidate config options
- mcu/samd21: enable MICROPY_STACK_CHECK on SAMD21
- enable support for Python USB devices
- README: fix incorrect port directory name
- boards: enable MICROPY_HW_DFLL_USB_SYNC on appropriate boards
- mcu: update clock config after changes to USB
- samd_spiflash: allow configuring the flash SPI baudrate
- samd_qspiflash: avoid reading status byte 2 when not available
- mcu: guard static function with appropriate #if

stm32 port:
- mboot: improve detection of invalid flash erase/write
- mboot: improve mass erase to erase all non-protected pages
- flash: remove commented-out flash functions
- flash: simplify sector calculation for homogeneous flash layout
- flash: change flash_erase to only erase a single sector at a time
- flashbdev: don't rely on flash sector id
- flash: factor and simplify erase code
- flash: fix sector and bank calculation for H5 and H7 MCUs
- mboot/Makefile: revert change to BOARD_DIR that removed abspath
- disable qstr hashing on small boards
- boards/ARDUINO_PORTENTA_H7: add pin configuration for SPI1
- modos: allow disabling MICROPY_PY_MACHINE_UART
- spi: allow disabling MICROPY_PY_MACHINE_SPI
- main: allow disabling MICROPY_PY_MACHINE
- Makefile: ignore uninitialised variable warning in H5 HAL SD code
- mboot: generate FLASH_LAYOUT_STR at runtime on H5 MCUs
- mpbthciport: allow building with MICROPY_PY_MACHINE_UART disabled
- sdram: support remapping FMC memory banks
- network_lan: allow defining phy_addr in the LAN constructor
- eth: remove redundant ETH clock enable code
- network_lan: add the phy_type=x keyword option to network.LAN()
- simplify D-cache clean and invalidate macros
- mpu: rename MPU_CONFIG_DISABLE to MPU_CONFIG_NOACCESS
- dma: add D-cache protection for DMA RX operations, including SPI
- add support for dual-analog-pad "_C" pins on H7 MCUs
- boards: add named digital and analog pins for Arduino boardrs
- sdram: fix MPU config to use MPU_CONFIG_NOACCESS
- mpu: add MPU config for shared, uncached memory region
- implement port backend for libmetal
- implement port backend for OpenAMP's remoteproc
- boards/ARDUINO_GIGA: enable OpenAMP
- boards/ARDUINO_NICLA_VISION: enable OpenAMP
- boards/ARDUINO_PORTENTA_H7: enable OpenAMP
- mboot: add support for a raw filesystem
- boards/LEGO_HUB_NO6: move robust logic to mboot
- boards/LEGO_HUB_NO6: use a raw filesystem for mboot to update fw
- stm32.mk: enable _Float16 support on MCUs with hardware floats
- boards/ARDUINO_GIGA: add Arduino's external library
- boards/ARDUINO_NICLA_VISION: add Arduino's external library
- boards/ARDUINO_PORTENTA_H7: add Arduino's external library
- README: update list of supported STM32 series
- set the security mode for the default WiFi AP
- mpremoteprocport: use metal logging functions
- boards/LEGO_HUB_NO6: write key after writing elements
- boards/LEGO_HUB_NO7: add robust update logic to mboot
- flash: fix writing final words to flash on H5 and H7 MCUs
- mboot: buffer the correct amount of bytes for a flash write
- i2c: fix clock enable for I2C4 on STM32F7 MCUs
- pyb_can: fix STM32G4 FDCAN source clock frequency

unix port:
- variants: prefer unix-ffi packages when loading the manifest
- input: flush the prompt after writing it to stdout
- don't include system headers when features are disabled
- variants: don't use native _Float16 type

webassembly port:
- Makefile: remove --memory-init-file from linker options
- include lib in sys.path
- move MP_JS_EPOCH init to library postset
- implement MICROPY_PY_RANDOM_SEED_INIT_FUNC
- enable time localtime, gmtime, time, time_ns
- use POSIX write for output and add stderr
- add support for enabling MICROPY_GC_SPLIT_HEAP_AUTO
- clean up Makefile and add variant support
- add JavaScript proxying, and js and jsffi modules
- implement runPythonAsync() for top-level async code
- implement runCLI() for a Node-based CLI
- implement replInit() and replProcessChar()
- variants/pyscript: add pyscript variant
- update README.md to describe latest changes
- library: fix formatting and style for Biome
- proxy_c: ensure return value of async fun is passed to JS
- proxy_js: promote Python thenable to a Promise
- proxy_js: allow a Python proxy of a function to be undone
- api: fix waiting for Emscripten module to be loaded
- api: allocate code data on C heap when running Python code
- objjsproxy: fix handling of thrown value into JS generator
- proxy_c: fix proxy then reject handling
- proxy_c: fix then-continue to convert reason to throw value
- modjsffi: add jsffi.async_timeout_ms
- add JavaScript-based asyncio support
- api: inject asyncio.run if needed by the script
- api: fix importing micropython.mjs module from node REPL
- proxy_c: reject promises with a PythonError instance
- proxy_c: only proxy across resolve/reject funs when needed
- objjsproxy: fix proxying in arguments to JS new function
- objpyproxy: implement JS iterator protocol for Py iterables
- api: resolve thenables returned from runPythonAsync
- proxy_c: support more than 4 args when JS calls Py func
- asyncio: fix case where a Promise is resolved with no arg
- proxy_c: ensure objs thrown into generators are exceptions
- proxy_js: convert JS undefined and JS null to Py None
- mpconfigport: enable importing of .mpy files
- proxy_js: revert back to converting Py None to JS null
- proxy_js: create a special "undefined" type for Python
- proxy_c: return undefined if dict lookup failed on JS side
- objjsproxy: make jsproxy_it keep ref to jsproxy
- proxy_c: don't return value of a void function
- track the current depth of calls to external C functions
- set GC threshold and do top-level GC collect when possible
- add C-level finaliser to JsProxy object
- register PyProxy objects for JS-side finalisation
- modjsffi: add mem_info function to get detailed stats

windows port:
- windows_mphal: fix mp_hal_delay_ms() so it runs events
- Makefile: fix float exact int formatting on 32-bit mingw

zephyr port: no changes specific to this component/port

Patch release for rp2 DMA, UART and BLE, esp32 BLE, renesas-ra I2C

This is a patch release containing the following commits:
- py/compile: fix potential Py-stack overflow in try-finally with return
- extmod/asyncio: support gather of tasks that finish early
- extmod/modssl_mbedtls: fix cipher iteration in SSLContext.get_ciphers
- extmod/btstack: reset pending_value_handle before calling write-done cb
- extmod/btstack: reset pending_value_handle before calling read-done cb
- esp32/mpnimbleport: release the GIL while doing NimBLE port deinit
- esp32: increase NimBLE task stack size and overflow detection headroom
- mimxrt/modmachine: fix deepsleep wakeup pin ifdef
- renesas-ra/ra: fix SysTick clock source
- renesas-ra/boards/ARDUINO_PORTENTA_C33: fix the RTC clock source
- renesas-ra/ra/ra_i2c: fix 1 byte and 2 bytes read issue
- rp2/rp2_dma: fix fetching 'write' buffers for writing not reading
- rp2/machine_uart: fix event wait in uart.flush() and uart.read()
- rp2: change machine.I2S and rp2.DMA to use shared DMA IRQ handlers

Patch release for rp2 atomic mutex

This is a patch release to fix a race condition and potential deadlock in
the rp2 port's mp_thread_begin_atomic_section() function, when the second
core is in use.

SSL support in asyncio, sorted qstr pools, common machine module bindings

This release of MicroPython introduces SSL/TLS support to asyncio, for both
the client and server sides.  The interface matches CPython:
`asyncio.open_connection()` and `asyncio.start_serve()` now both accept an
`ssl` argument to supply an `SSLContext` object.  As part of this, new
methods were added to `SSLContext` to load certificates, and certificate
date/time validation was enabled on all ports that use mbedTLS.

Qstr pools are now sorted, which provides a significant performance boost
for `qstr_find_strn()`, which is called a lot during parsing and loading of
.mpy files, as well as interning of string objects, which happens in most
string methods that return new strings.  The static pool (part of the .mpy
ABI) isn't currently sorted, but could be in the future.

There have been many internal changes to the `machine` module (and on some
ports the `os` module) to factor the Python bindings to a common location,
reduce code duplication and make the API more consistent across all the
ports.  And a new `boardgen.py` script has been added to factor pin
generation and enable a more consistent `machine.Pin` across ports.  For
consistency, the following user-facing changes have been made:

- cc3200 port: The `machine` module gains `soft_reset()`, `mem8`, `mem16`,
  `mem32` and `Signal`; it loses `POWER_ON` (replaced by `PWRON_RESET`).
  `disable_irq()` now returns an (opaque) integer rather than a bool, and
  `enable_irq(state)` must be passed an argument which is the return value
  of `disable_irq()`, rather than a bool.  In the `os` module, `dupterm()`
  has been converted to use the common implementation and has semantics the
  same as other ports, and `uname()` is removed to save space (sys.version
  and sys.implementation can be used instead).

- esp32 port: In the `machine` module, `lightsleep()` and `deepsleep()` no
  longer take the `sleep` keyword argument, instead it's positional to
  match other ports.  Also, passing 0 here will now do a 0ms sleep instead
  of acting like nothing was passed.  And `reset_cause()` no longer accepts
  any arguments (before it would just ignore them).

- esp8266 port: `machine.idle()` now returns None instead of the time
  elapsed.  The `machine.WDT()` constructor now takes keyword arguments,
  and accepts the `timeout` argument but raises an exception if it's not
  the default value (this port doesn't support changing the timeout).

- mimxrt port: `machine.freq()` now accepts an argument but raises
  `NotImplementedError`, and `machine.lightsleep()` has been added but also
  just raises `NotImplementedError` (this is to make these functions use an
  implementation common to the other ports).

- nrf port: The `machine` module gains `unique_id()` (returns an empty
  bytes object), `freq()` (raises `NotImplementedError`) and `Signal`.
  `UART.sendbreak()` is removed, but this method previously did nothing.
  The `os.dupterm()` function has changed to match the semantics used by
  all other ports (except it's restricted to accept only `machine.UART`
  objects).

- qemu-arm port: The `machine` module gains `soft_reset()` and `idle()`.

- samd port: The `machine.deepsleep()` function now resets after sleeping.

- unix port: Gains `machine.soft_reset()`.

- zephyr port: The `machine` module gains `soft_reset()`, `mem8`, `mem16`,
  and `mem32`.  The `UART` class gains the following methods: `init()`
  which supports setting `timeout` and `timeout_char`, `deinit()` which
  does nothing, `flush()` which raises `OSError(EINVAL)` because it's not
  implemented, and `any()` and `txdone()` which both raise
  `NotImplementedError`.

The teensy port has been removed in this release.  This port was largely
unmaintained, had limited features (the only hardware support was for GPIO
and timer, and no `machine` module), and only supported a small number of
Teensy boards.

A new preview versioning scheme has been introduced, whereby non-release
builds are a preview of the next, upcoming release.  This scheme is
compatible with semver and should help to eliminate confusion matching
documentation and firmware version numbers, among other things.

Black has been replaced with ruff format as the Python code formatter.
This required a few small changes to Python code, and now allows linting
and formatting with ruff.

Bound method instances now support comparison and hashing, matching CPython
semantics.  The .mpy sub-version has been updated from 6.1 to 6.2 due to a
change in the native .mpy ABI.  A new option `MICROPY_PREVIEW_VERSION_2`
has been added which provides a way to enable features and changes slated
for MicroPython 2.x, by running `make MICROPY_PREVIEW_VERSION_2=1`.  This
is an alternative to having a 2.x development branch, and any feature or
change that needs to be "hidden" until 2.x will use this flag.

LittleFS has been updated to v2.8.1.  The associated MicroPython VfsLfs2
driver can read existing LFS2 filesystems, but any writes will update the
filesystem to a newer LFS2 version that cannot be read by older drivers, so
take this into account when updating, for example update mboot first.

The VFS sub-system has a new file ioctl to set the read-buffer size, which
is used by mpremote to significantly increase performance of the
"mpremote mount" feature.  Manifest files now allow registering an external
library path via `add_library(name, path)`.  `sys.stdout.buffer.write()`
now returns the actual number of bytes written (although this is
complicated when output goes to multiple destinations).

The esp32 port has been updated to use IDF version 5.0.4, and the initial
GC heap size tuned so that, after doubling the heap size, WiFi can still be
started and an SSL connection made.  `RMT.source_freq()` is now a class
method, socket connect timeout has been implemented, RTC user memory is now
preserved over most reset causes, and `hashlib.md5` enabled.

The mimxrt port has RTC alarm/wakeup functionality added, along with
support for `machine.deepsleep()`.

The rp2 port sees the introduction of a new `rp2.DMA` class for control
over DMA transfers.  It has switched to use the same math library as other
ports to get more accurate floating point behaviour, and enabled
`os.dupterm_notify()` for WebREPL use.  The TinyUSB stack is now scheduled
to run from the IRQ handler (instead of polled in the VM) which slightly
improves performance of the VM and USB.  The port also makes better use of
event scheduling and WFE to be more efficient.  It also has added support
for external ADC channels (for example when using the ninaw10 driver).

The stm32 port has improved support for STM32H5xx MCUs, including Ethernet
support, frequency scaling with HSI, sleep mode and SD card support.  The
NUCLEO_WL55 board now freezes in the LoRa driver, the I2S driver has
improved accuracy of the clock frequency, and mboot now supports Microsoft
WCID to set the USB driver.

New boards added in this release are: UM_TINYWATCHS3 (esp32 port),
POLOLU_3PI_2040_ROBOT, POLOLU_ZUMO_2040_ROBOT and SIL_RP2040_SHIM (rp2
port), NUCLEO_H563ZI (stm32 port).

The change in code size since the previous release for various ports is
(absolute and percentage change in the text section):

       bare-arm:   +216  +0.381%
    minimal x86:   +624  +0.340%
       unix x64:  +8283  +1.050%
          stm32:  +1368  +0.350%
         cc3200:  +1184  +0.649%
        esp8266:   +800  +0.114%
          esp32: +35348  +2.100%
         mimxrt:  +2172  +0.602%
     renesas-ra:    +96  +0.015%
            nrf:  +1460  +0.785%
            rp2:  +6100  +1.880%
           samd:  +1476  +0.568%

The changes that dominate these numbers are:
- bare-arm, minimal: comparing and hashing bound methods, sorted qstr pools
- unix: updating LittleFS to 2.8.1, enabling certificate date/time
  validation, adding SSLContext certificate methods, asyncio SSL support
- stm32: sorted qstrs, updating LittleFS to 2.8.1, I2S clock frequency
  improvements, asyncio SSL support
- cc3200: sorted qstrs, more machine module functions, use of the common
  `os.dupterm` implementation
- esp32: switching ESP-IDF from 5.0.2 to 5.0.4
- esp8266: updating LittleFS to 2.8.1
- mimxrt: adding RTC alarm/wakeup functionality, updating LittleFS to
  2.8.1, asyncio SSL support
- nrf: updating LittleFS to 2.8.1, enabling `machine.Signal`, asyncio SSL
  support
- rp2: using locally-provided math library, adding new `rp2.DMA` class
- samd: sorted qstrs, updating LittleFS to 2.8.1, asyncio SSL support

With the new sorted qstr pools, performance is significantly improved for
qstr-heavy operations, between +50% and +200% improvement.  Other areas
have their performance unchanged since the last release.

Thanks to everyone who contributed to this release: Alessandro Gatti,
Andrew Leech, Angus Gratton, Carlosgg, Christian Walther, Damien George,
Daniël van de Giessen, Elias Wimmer, Glenn Moloney, iabdalkader, Ihor
Nehrutsa, Jeff Epler, Jim Mussared, Kwabena W. Agyeman, Maarten van der
Schrieck, Mark Blakeney, Mathieu Serandour, Matthias Urlichs, MikeTeachman,
Ned Konz, Nicko van Someren, Pascal Brunot, Patrick Van Oosterwijck, Paul
Grayson, Peter Züger, Rene Straub, robert-hh, Scott Zhao, Sebastian Romero,
Seon Rozenblum, stijn, Thomas Ackermann, Thomas Wenrich, ThomHPL, Trent
Piepho.

Contributions were made from the following timezones: -0800, -0700, -0600,
-0500, +0000, +0100, +0200, +1000, +1100.

The work done in this release was funded in part through GitHub Sponsors,
and in part by George Robotics, Planet Innovation, Espressif, Arduino, LEGO
Education and OpenMV.

What follows is a detailed list of changes, generated from the git commit
history, and organised into sections.

Main components
===============

all:
- switch to new preview build versioning scheme
- replace "black" with "ruff format"
- update Python formatting to ruff-format

py core:
- vm: don't emit warning when using "raise ... from None"
- builtinevex: handle invalid filenames for execfile
- objboundmeth: support comparing and hashing bound methods
- objboundmeth: optimise check for types in binary_op
- obj: generalise mp_get_buffer so it can raise if a flag is set
- dynruntime: add mp_get_buffer
- persistentcode: bump .mpy sub-version
- modthread: initialise nlr_jump_callback_top on threads
- makeqstrdefs.py: print a nicer error when preprocessing stage fails
- mkrules.mk: add MICROPY_PREVIEW_VERSION_2
- asm: remove unused asm helper macros
- qstr: add support for sorted qstr pools
- mkrules.mk: add rule for compiling auto-generated source files
- runtime: remove declaration of function from inside function
- lexer: change token position for new lines
- misc: change sizeof to offsetof for variable-length alloc
- qstr: special case qstr_find_strn for empty string
- obj: fix mp_obj_is_type compilation with C++
- objslice: validate that the argument to indices() is an integer
- mkrules: add support for custom manifest variables
- modbuiltins: share vstr_add_char's implementation of utf8 encoding
- mphal: move configuration of ATOMIC_SECTION macros to mphal.h
- add port-agnostic inline functions for event handling
- modsys: implement optional sys.intern
- mkrules.mk: list hash files as byproducts
- makeqstrdefs.py: don't skip output for stale hash file
- makeqstrdefs.py: stop generating temporary intermediate file
- gc: improve calculation of new heap size in split-heap-auto mode
- mkrules.mk: fix dependency file generation for compiler wrappers

extmod:
- moductypes: validate that uctypes.struct addr argument is an int
- asyncio: emit errors to stderr, not stdout
- modframebuf: validate FrameBuffer bounds against input buffer
- modframebuf: fix FrameBuffer get-buffer implementation
- modframebuf: remove FrameBuffer1 from natmod build
- vfs_posix: fix relative root path
- vfs_posix: fix accidentally passing tests
- vfs_posix: fix relative paths on non-root VFS
- vfs_posix: fix getcwd() on non-root VFS
- vfs_posix: additional tests for coverage of error cases
- network_ninaw10: raise an error if nina_ioctl fails
- machine_wdt: factor ports' WDT Python bindings to common code
- machine_pwm: remove header file and move decls to .c file
- machine_i2s: factor ports' I2S Python bindings to common code
- machine_i2s: factor stream and ring-buf code
- machine_i2s: factor I2S.shift method
- machine_i2s: factor I2S.irq method
- machine_i2s: factor print function
- machine_i2s: factor init_helper argument parsing
- machine_i2s: factor comments, some enums and macros
- machine_adc: factor ports' ADC Python bindings to common code
- machine_uart: factor ports' UART Python bindings to common code
- modmachine: clean up decls of machine types to use common ones
- modmachine: consolidate simple machine headers into modmachine.h
- modmachine: consolidate mem, i2c and spi headers to modmachine.h
- network_ninaw10: fix select flags handling in socket poll
- remove empty utime_mphal.h file
- machine_adc_block: factor esp32 ADCBlock bindings to common code
- machine_i2c: do a fast poll during I2C.scan()
- vfs_reader: add file ioctl to set read buffer size
- modbluetooth: initialise nlr_jump_callback_top for IRQ handlers
- vfs_posix_file: make standard file objects non-const
- extmod.mk: allow enabling lwip loopback support
- modmachine: make I2C/SPI defns available when soft impl enabled
- modmachine: factor ports' machine module dict to common code
- modmachine: provide common Python bindings for machine.idle()
- modmachine: add MICROPY_PY_MACHINE_PIN_BASE option
- modmachine: provide common Python bindings for bootloader()
- modmachine: provide common bindings for 6 bare-metal functions
- modmachine: provide common implementation of disable/enable_irq
- mbedtls: enable certificate time/date validation by default
- modnetwork: add deinit function to NIC protocol
- network_ninaw10: switch to using soft-timer for polling
- switch to use new event functions
- add lists of libm/libm_dbl source files for ports to use
- modssl_mbedtls: add SSLContext certificate methods
- modssl_mbedtls: make SSLSocket.getpeercert() optional
- modssl_mbedtls: fix parsing of ciphers in set_ciphers method
- asyncio: add ssl support with SSLContext
- modonewire: adopt Maxim recommended read timings
- modonewire: improve write timings for better reliability
- modos: factor os.dupterm_notify() function to common extmod code
- os_dupterm: prevent recursive execution of mp_os_dupterm_rx_chr
- asyncio: remove non-working Stream __aenter__/__aexit__ methods
- modselect: handle growing the pollfds allocation correctly
- modhashlib: support MD5 with mbedtls 3.x
- os_dupterm: let mp_os_dupterm_tx_strn() return num bytes written
- vfs_lfs: fix lfs cache_size calculation
- nimble: do not set GAP device name after sync

shared:
- libc/string0: don't deref args for n==0 case
- tinyusb: schedule TinyUSB task function from dcd_event_handler
- tinyusb: expose mp_usbd_task as a public function
- tinyusb: add a helper for hex string conversion
- runtime/softtimer: generalise soft_timer to work without SysTick

drivers:
- ninaw10: add ioctl for reading analog pins
- ninaw10: add support for external ADC channels

mpy-cross: no changes specific to this component/port

lib:
- littlefs: update LittleFS to v2.8.1
- uzlib: for matches of the same length, take the closest one
- mbedtls_errors: update error list for latest esp32 mbedtls
- micropython-lib: update submodule to latest

Support components
==================

docs:
- reference/mpyfiles: document change in .mpy sub-version
- library/io: remove io.FileIO and io.TextIOWrapper
- reference/micropython2_migration: add migration guide
- mimxrt: change the examples which denote a Pin with a number
- samd: fix the pinout for SAMD21 Itsy Bitsy Express M0
- library/esp: correct the description of esp.osdebug()
- esp32/quickref: add DAC example
- library: document SSLContext cert methods and asyncio support

examples:
- pins.py: remove this pins printing example

tests:
- basics/boundmeth1.py: add tests for bound method equality/hash
- perf_bench: add string/qstr/map tests
- extmod/asyncio_as_uasyncio.py: fix qstr order dependency
- net_hosted/asyncio_loopback.py: add loopback test
- extmod/deflate_compress.py: add a test for optimal compression
- float/inf_nan_arith.py: include -inf in argument combos
- run-tests.py: skip Thumb2 tests if target doesn't support them
- update SSL network tests to use SSLContext, and work on CPython

tools:
- ci.sh: ensure enough commits are fetched for a common ancestor
- boardgen.py: add initial implementation of a common make-pins.py
- tinytest-codegen.py: externalise tests list
- mpremote: add ioctl to specify large read buffer size
- ci.sh: build ESP32_GENERIC-SPIRAM as part of esp32 CI
- ci.sh: set `ulimit -n` for unix CI
- manifestfile.py: add support for external libraries

CI:
- workflows: pin ruff to 0.1.0 and change flags for new version
- workflows: cache ESP-IDF checkout and installation
- workflows: use build matrix for esp32 port
- workflows: enable build matrix for stm32 port
- workflows: enable ccache for esp32 build
- workflows: bump actions/github-script from 6 to 7
- workflows: bump actions/setup-python from 4 to 5
- workflows: bump actions/upload-artifact from 3 to 4

The ports
=========

all ports:
- make all ports skip execution of main.py if boot.py fails
- remove SRC_QSTR_AUTO_DEPS from all ports' Makefiles
- standardise arguments and output for make-pins.py script
- fix incorrect identifiers on Arduino boards
- move definitions of ATOMIC_SECTION macros to mphalport.h
- switch build to use common lib/libm list of source files
- fix sys.stdout.buffer.write() return value

bare-arm port:
- lib: add minimal strncmp implementation

cc3200 port:
- boards/make-pins.py: don't generate qstrs
- boards/make-pins.py: add a note about tools/boardgen.py
- mods/modmachine: use common implementation of disable/enable_irq
- convert dupterm to use common extmod implementation
- convert os module to use extmod version
- eliminate dependency on stm32's irq.h
- application.mk: don't add stm32 to build include path

embed port: no changes specific to this component/port

esp8266 port:
- rename MICROPY_ESPNOW to MICROPY_PY_ESPNOW
- machine_spi: rename machine_hspi to machine_spi
- esp_mphal: make atomic section more atomic
- modmachine: use common implementation of disable/enable_irq
- avoid including ep_mphal.h directly
- update port to use new event functions

esp32 port:
- rename MICROPY_ESPNOW to MICROPY_PY_ESPNOW
- boards: update UM board image names for consistency
- boards/UM_TINYWATCHS3: add new UM TinyWATCH S3 board
- boards: update UM board settings to use custom PID/VID
- network_ppp: allow building with IPv6 disabled
- poll serial/JTAG for unread data to prevent blocking
- mpconfigport: remove port-specific GAP name
- machine_uart: add error checking for IDF API's
- network_ppp: reduce PPP thread CPU usage
- boards: disable ALPN support
- network_lan: fix and simplify the code for ETH-SPI devices
- network_lan: fix LAN.isconnected()
- network_lan: register the hostname setting for Ethernet
- modmachine: fix deepsleep() when previous sleep delay was set
- boards: reduce size of D2WD and OTA firmware
- use better build settings for ESP32-C3
- mphalport: add function to wake main from separate FreeRTOS task
- usb: wake main thread when USB receives data
- machine_pin: make irq object a sub-field of pin object
- esp32_rmt: change RMT.source_freq() to class method
- esp32_rmt: add RMT.PULSE_MAX constant
- modsocket: implement socket connect timeout
- modsocket: try garbage collection if the socket limit is reached
- boards/sdkconfig.base: fix increasing log level via esp.osdebug()
- boards/ESP32_GENERIC: reduce size of D2WD variant to fit in flash
- uart: preserve console UART clock, fix UART console with DFS
- uart: make compatible with sclk type change in ESP-IDF 5.3
- network_wlan: reduce RAM usage if SPIRAM fails to initialise
- network_wlan: fix network.WLAN.status() to return better info
- esp32_rmt: fix RMT looping
- enable mbedtls cert time validation
- boards: enable further IRAM saving opts to fit ESP32-SPIRAM fw
- machine_rtc: preserve RTC user memory over most reset causes
- boards/UM_TINYPICO: fix typo in baudrate instructions
- boards/sdkconfig.base: disable unused mbedtls options
- machine_i2c: use APB_CLK_FREQ instead of I2C_APB_CLK_FREQ
- modnetwork: add WiFi AUTH_WPA3_ENT_192 authenticate mode
- machine_dac: support one-shot mode of driver
- modmachine: fix deprecated esp_pm_config_XXX_t
- machine_i2s: fix deprecated fields and constants
- mpconfigport: keep some funcs out of IRAM for ESP32-SPIRAM builds
- boards/ESP32_GENERIC: disable network.LAN and VM-opt on D2WD
- change minimum supported IDF version to v5.0.4
- re-enable custom mbedtls error string tables
- add MICROPY_GC_INITIAL_HEAP_SIZE option and tune it
- mpconfigport: enable MICROPY_PY_HASHLIB_MD5

mimxrt port:
- led: fix LED init call from main, and simplify led_init
- boards: define missing SNVS pins for all processors
- machine_rtc: add RTC alarm/wakeup functionality
- modmachine: add support for machine.deepsleep
- boards/make-pins.py: update to use tools/boardgen.py
- modmachine: fix settings for the MIMXRT1170 board
- boards/OLIMEX_RT1010: adjust the UART pin assignment

minimal port: no changes specific to this component/port

nrf port:
- boards: automatically configure MICROPY_PY_MACHINE_PWM
- modules/machine: use SPI Python bindings provided by extmod
- boards/make-pins.py: don't generate qstrs
- boards/make-pins.py: add a note about tools/boardgen.py
- use MICROPY_PY_MACHINE_SPI instead of MICROPY_PY_MACHINE_HW_SPI
- use dupterm_objs[0] instead of board_stdio_uart
- convert os module to use extmod version
- mpconfigport: enable MICROPY_PY_MACHINE_BOOTLOADER
- boards/ARDUINO_NANO_33_BLE_SENSE: don't enable MICROPY_MBFS
- main: add /flash and /flash/lib to sys.path

pic16bit port: no changes specific to this component/port

powerpc port: no changes specific to this component/port

qemu-arm port: no changes specific to this component/port

renesas-ra port:
- boards/make-pins.py: don't generate qstrs
- boards/make-pins.py: update to use tools/boardgen.py
- boards/ARDUINO_PORTENTA_C33: fix incorrect I2C pins
- consolidate MICROPY_PY_MACHINE_I2C option

rp2 port:
- cyw43_configport: use m_tracked_calloc and m_tracked_free
- machine_adc: add support for external ADC channels
- boards/ARDUINO_NANO_RP2040_CONNECT: add external analog pins
- boards/make-pins.py: don't generate qstrs
- machine_uart: fix handling of serial break condition
- machine_adc: refactor channel/pin validation code
- remove 1ms timeout to make idle waiting tickless
- change to use TinyUSB dcd_event_handler hook
- mphalport: run TinyUSB stack while waiting for CDC input/output
- integrate soft_timer using the alarm pool
- mpbthciport: rework HCI polling timer to use soft_timer
- mpnetworkport: rework lwIP polling to use soft_timer
- mphalport: optimise exit of mp_hal_delay_ms loop
- cyw43_configport: implement cyw43_delay_ms as mp_hal_delay_ms
- switch to locally provided math library
- switch rp2 and drivers to use new event functions
- main: enable SEVONPEND CPU interrupt bit
- mpconfigport: enable MICROPY_PY_OS_DUPTERM_NOTIFY
- add new NO_DEFAULT_PINS config options for i2c, spi, and uart
- boards: add support for Pololu 3pi+ and Zumo robots
- boards: add SIL_RP2040_SHIM board by Silicognition LLC
- rp2_dma: introduce a new rp2.DMA class for control over DMA xfers

samd port:
- boards/make-pins.py: update to use tools/boardgen.py
- mpconfigport: set MICROPY_USE_INTERNAL_ERRNO to 1
- machine_uart: add machine_uart_set_baudrate() function
- pin_af: fix a typo in a conditional compile
- switch TinyUSB to run via a scheduled task
- mphalport: run TinyUSB stack while waiting for CDC input/output
- switch to shared TinyUSB implementation
- use unique id for USB serial number

stm32 port:
- boards/ARDUINO_GIGA: add QSPI fix/workaround to early init
- boards/ARDUINO_GIGA: fix name of pins in board init
- eth: add Ethernet support for H5 MCUs
- boards/STM32H573I_DK: enable ETH and DAC peripherals
- powerctrl: add support for frequency scaling with HSI on H5 MCUs
- boards/make-pins.py: don't generate qstrs
- boards: fix errors in pins.csv and af.csv
- boards: format stm32 alternate function csv files
- rename pin_obj_t to machine_pin_obj_t
- boards/make-pins.py: update to use tools/boardgen.py
- boards/make-pins.py: add initial support for H7 dual-pad pins
- add configuration options for analog switches
- add STM32H5 support for sleep mode
- boards/make-pins.py: fix H7 ADC generation
- boards/stm32f4x9_af.csv: fix DCMI_VSYNC
- boards/stm32g474_af.csv: fix final row ADC column
- boards/make-pins.py: only support ADC1-3
- boards/NUCLEO_WL55: freeze LoRa driver
- mpu: enable STM32WB mpu use to support qspi flash
- add optional lwip loopback support
- boards/NUCLEO_F446RE: add UARTs 1, 3 and 4
- boards/NUCLEO_H563ZI: add new NUCLEO-H563ZI board definition
- sdcard: add SD card support for H5 MCUs
- boards/STM32H573I_DK: enable the SD card
- add missing header include for debug builds
- modmachine: only enable machine.I2C if hardware I2C is enabled
- usbd_cdc_interface: include header to get machine_bootloader decl
- machine_i2s: improve accuracy of SCK frequency
- usbdev: optionally pass through vendor requests to Setup function
- mboot: guard use of tx_pending with USE_USB_POLLING option
- mboot: expand device descriptor to make it easier to understand
- mboot: add support for Microsoft WCID

teensy port:
- remove the teensy port

unix port:
- mbedtls: enable mbedtls cert time validation
- update port to use the new event functions

webassembly port: no changes specific to this component/port

windows port:
- use the MicroPython logo as application icon
- implement MICROPY_INTERNAL_WFE() macro

zephyr port: no changes specific to this component/port

U-module renaming, deflate module, IDF 5, board variants and Pico-W BLE

This release of MicroPython sees the renaming of built-in modules to remove
the u-prefix, a new deflate module with optional compression support, the
introduction of board variants, switching of the esp32 port to use IDF 5
together with improved heap management, support for BLE on RPi Pico W
boards, and STM32H5xx support.  The project is also now using codespell and
ruff to improve code quality.  New boards added in this release are:
ARDUINO_NANO_ESP32 and UM_NANOS3 (esp32 port), ADAFRUIT_METRO_M7 (mimxrt
port), ARDUINO_PORTENTA_C33 and VK_RA6M5 (renesas-ra port),
ADAFRUIT_METRO_M4_EXPRESS (samd port), NUCLEO_L4A6ZG and STM32H573I_DK
(stm32 port).

The renaming of built-in modules to remove the u-prefix -- for example
utime becomes time, uasyncio becomes asyncio -- is done to improve
compatibility with CPython and eliminate confusion about whether to import
the u-version or the non-u-version of the name.  Now, one should just
always import the non-u-version and no longer think about u-naming.  The
only remaining module with a u-prefix is uctypes because it is not
compatible with the CPython ctypes modules.  The following modules are
still available via their u-names for backwards compatibility: array,
asyncio, binascii, bluetooth, collections, cryptolib, errno, hashlib,
heapq, io, json, machine, os, platform, random, re, select, socket, ssl,
struct, time, websocket.  These modules (except for asyncio) are also
extensible and can be overridden by a file with the same name, eg time.py.
To force the import of a built-in, one must first clear (and subsequently
restore) sys.path; the ability to write to the sys.path attribute has also
been implemented in this release.  For further information see the
discussion at https://github.com/micropython/micropython/issues/9018.

Furthermore, importing itself has been tweaked and optimised, and importing
of built-ins no longer touch the filesystem, which makes a typical built-in
import take ~0.15ms rather than 3-5ms.  For modules that fail to import,
they are now removed from sys.modules, allowing the import to be attempted
again.  This required adding "NLR jump callbacks" to efficiently run some
code if an exception is raised.

Additional improvements to the core runtime include support for conversion
specifiers in f-strings (e.g. !r), speeding up of incremental GC cycles by
tracking the last used block, addition of a new MICROPY_GC_SPLIT_HEAP_AUTO
"auto grow heap" mode and support for pad bytes in struct format.  The
documentation, examples and test have also seen general improvements and
additions.

For the extended modules, the zlib C module has been removed and replaced
with a new MicroPython-specific deflate module and DeflateIO class that is
optimised to provide efficient streaming compression and decompression.
The zlib (and gzip) modules are now implemented in pure Python on top of
the deflate module.  The timeq module has been removed, it existed only for
a previous version of (u)asyncio and is no longer used.  In the ssl
module, SSLContext has been added to be more compatible with CPython.  The
select module now supports using system/POSIX poll when possible and the
unix port now uses this implementation instead of its own one.  That means
the unix port can now select/poll on custom Python objects that implement
the appropriate ioctl.  The socket module now supports SO_BROADCAST, and
sys.std*.buffer objects now exist on unix.  There is also a new esp-hosted
network driver for external ESP32-based network coprocessors.

mpy-cross now allows reading source files from stdin and writing compiled
code to stdout.

The esp8266 and esp32 ports add support for the Espressif ESP-NOW protocol,
and the ability to set/get the power saving mode of the WLAN hardware.  The
esp8266 port adds board-variant support, combining all boards into a single
ESP8266_GENERIC with FLASH_512K, FLASH_1M and OTA variants.

The esp32 port has now switched exclusively to ESP-IDF 5, and all existing
components have been updated to work with this new IDF (except
esp32.hall_sensor() which has been removed).  The FSM ULP has been enabled
for S2 and S3 chips, sockets now support SO_BINDTODEVICE, and board-named
pins and the Pin.board dict have been implemented.  The MicroPython heap
has been reworked on this port to support the large variety of memory
configurations: it now starts at 64kbytes and automatically grows as
needed, with new segments allocated from the IDF heap.  This means that
boards with SPIRAM have much faster GC collection times if only a small
amount of RAM is used, all available RAM can be used if needed, and the IDF
has access to enough RAM for things like SSL sockets.  For more information
see https://github.com/micropython/micropython/pull/12141.  The esp32 port
has also had its generic boards consolidated and renamed to ESP32_GENERIC,
ESP32_GENERIC_C3, ESP32_GENERIC_S2 and ESP32_GENERIC_S3, and some now have
variants such as SPIRAM.

The mimxrt port has fixes and improvements to PWM and Pin.irq, as well as
support for UART hardware flow control and UART.deinit.  It has also seen
integration of WiFi via the CYW43 driver, and Bluetooth via NimBLE.  The
mbedTLS bindings have enabled time validation of certificates.

The renesas-ra port has changed board names to match the product name,
updated to use FSP v4.4.0, added support for: RA6M5 MCUs, machine PWM, DAC,
RNG and SDCard classes, TinyUSB, Bluetooth via NimBLE, networking via lwIP,
and mbedTLS.

Bluetooth support has also been added to the rp2 port for the Pico W board.
And the RPi boards have been renamed from PICO to RPI_PICO, and PICO_W to
RPI_PICO_W.  Lightsleep has been fixed on this port so it works while WiFi
is powered off, and time.time_ns() now has microsecond resolution.

The samd port sees the addition of SPI and QSPI flash drivers to support
filesystems on external flash.

The stm32 port add support for STM32H5xx MCUs, basic support for the
OCTOSPI peripheral, and USB support for STM32L1xx MCUs.  New functions have
been added to the stm module to support the sub-GHz radio on STM32WL55.

In micropython-lib, an extensive LoRa module has been added along with
drivers for SX126x and SX127x chipsets, and the STM32WL55.  This module
supports both synchronous and asynchronous (asyncio) mode.  Also, as part
of the u-module renaming, urequests has been renamed to requests (but for
backwards compatibility "import urequests" still works for now).

The change in code size since the previous release for various ports is
(absolute and percentage change in the text section):

       bare-arm:    +192  +0.340%
    minimal x86:    +310  +0.169%
       unix x64:   +4784  +0.610%
          stm32:    -524  -0.134%
         cc3200:    +280  +0.154%
        esp8266:   +8016  +1.151%
          esp32: +112133  +7.293%
         mimxrt:   +3624  +1.015%
     renesas-ra:   -2184  -0.348%
            nrf:    +616  +0.332%
            rp2:   +1920  +0.595%
           samd:   -7904  -2.953%

The changes that dominate these numbers are:
- bare-arm, minimal, cc3200, nrf: NLR jump callbacks and support for
  extensible modules
- unix: update of mbedTLS to v2.28.1, support for polling Python objects in
  select module
- stm32: removal of the timeq module
- esp8266: addition of the espnow module
- esp32: switching to ESP-IDF 5
- mimxrt: UART features, time validation of SSL certificates
- renesas-ra: move to FSP v4.4.0, remove timeq module
- rp2: machine.PWM enhancements
- samd: drop support for VfsLfs1

Performance is effectively unchanged since the previous release.

Note that this is the last release to use the current versioning scheme for
nightly/unstable builds, whereby a build between releases is versioned as
v1.20.0-<num>-g<hash> (following the release of v1.20.0).  Moving forward,
nightly builds will now be called preview builds and be versioned with the
next release number.  For example, if the last release was v1.21.0 then
preview releases will be of the form v1.22.0-preview.<num>.g<hash>.  For
discussion see https://github.com/micropython/micropython/issues/12127.

Thanks to everyone who contributed to this release:
Adam Green, Alexander Wilde, algonell, Andrew Leech, Andy Piper, Angus
Gratton, Armin Brauns, brave ulysses, Brett Cannon, Brian 'redbeard'
Harrington, Carlosgg, Chris Wilson, Christian Clauss, Damien George, Damien
Tournoud, Daniël van de Giessen, David Grayson, David Lechner, David Yang,
dotnfc, Duncan Lowther, Elecia White, elibdev, Elvis Pfutzenreuter, Felix
Dörre, Francis Dela Cruz, Glenn Moloney, glenn20, iabdalkader, Ihor
Nehrutsa, Jared Hancock, Jim Lipsey, Jim Mussared, Jon Nordby, Jonas
Scharpf, Jos Verlinde, Kwabena W. Agyeman, Luca Burelli, marble, Mark
Grosen, mbedNoobNinja, mcskatkat, Mingjie Shen, Mirko Vogt, Nicholas H.
Tollervey, Oliver Joos, Ondrej Wisniewski, patrick, Peter Harper, Phil
Howard, Philipp Ebensberger, Rene Straub, robert-hh, Sebastian Romero, Seon
Rozenblum, stephanelsmith, stijn, Takeo Takahashi, Thomas, Tobias
Thyrrestrup, UnexpectedMaker, Victor Rajewski, vsfos, Wang Xuancong, Wanlin
Wang, Wilko Nienhaus, Wind-stormger, Yaroslav Halchenko, Yilin Sun, Yuuki
NAGAO.

The work done in this release was funded in part through GitHub Sponsors,
and in part by George Robotics, Planet Innovation, Espressif, Arduino, LEGO
Education and OpenMV.

What follows is a detailed list of changes, generated from the git commit
history, and organised into sections.

Main components
===============

all:
- fix spelling mistakes based on codespell check
- fix strings with backslash by using raw string literals
- fix various Python coding inconsistencies found by ruff
- fix cases of Python variable assigned but never used
- rename MP_QSTR_umodule to MP_QSTR_module everywhere
- rename mp_umodule*, mp_module_umodule* to remove the "u" prefix
- rename mod_umodule*, ^umodule* to remove the "u" prefix
- rename UMODULE to MODULE in preprocessor/Makefile vars
- rename *umodule*.h to remove the "u" prefix
- rename *umodule*.c to remove the "u" prefix
- use MP_REGISTER_EXTENSIBLE_MODULE for overrideable built-ins
- replace all uses of umodule in Python code
- remove the zlib module
- remove query-variants make target
- add missing imports for micropython.const
- add Black configuration section to pyproject.toml
- add ruff to pre-commit
- CODECONVENTIONS: require that commits be signed-off by the author

py core:
- ringbuf: implement put_bytes/get_bytes functions
- parse: fix build when COMP_CONST_FOLDING=0 and COMP_MODULE_CONST=1
- compile: remove over-eager optimisation of tuples as if condition
- stackctrl: add gcc pragmas to ignore dangling-pointer warning
- gc: make improvements to MICROPY_GC_HOOK_LOOP
- obj: remove mp_generic_unary_op()
- objslice: ensure slice is not hashable
- objdict: fix __hash__ for dict_view types
- objarray: disallow memoryview addition
- objstr: return unsupported binop instead of raising TypeError
- runtime: if inplace binop fails then try corresponding normal binop
- change MP_UNARY_OP_INT to MP_UNARY_OP_INT_MAYBE
- obj: accept user types in mp_obj_get_int_maybe
- objint: allow int() to parse anything with the buffer protocol
- builtinimport: handle empty sys.path correctly
- builtinimport: optimise sub-package loading
- builtinimport: allow builtin modules to be packages
- objmodule: don't use sys.modules to track a builtin __init__
- nlrsetjmp: use MP_NLR_JUMP_HEAD macro to simplify code
- nlr: remove commented-out debugging code
- nlr: implement jump callbacks
- use nlr jump callbacks to optimise compile/execute functions
- builtinimport: remove partially-loaded modules from sys.modules
- builtinimport: remove weak links
- makemoduledefs.py: add a way to register extensible built-in modules
- objmodule: add a table of built-in modules with delegation
- objmodule: workaround for MSVC with no module delegation
- mpconfig: enable module delegation if sys needs it
- modsys: allow sys.path to be assigned to
- mkrules.mk: automatically configure frozen options when manifest set
- parsenum: fix typo in #endif comment
- nlraarch64: fix dangerous use of input register
- makemoduledefs.py: fix declaring multiple module delegations
- makemoduledefs.py: automatically declare delegation attr functions
- lexer: allow conversion specifiers in f-strings (e.g. !r)
- mkrules.mk: allow $(AFLAGS) to set flags to $(AS)
- compile: fix async for's stack handling of iterator expression
- builtinimport: fix built-in imports when external import is disabled
- stream: add mp_stream___exit___obj that calls mp_stream_close
- runtime: always initialise sched_state in mp_init
- mpconfig: add MICROPY_PY_PLATFORM, enabled at extra features level
- gc: speed up incremental GC cycles by tracking the last used block
- gc: apply some code formatting cleanup
- gc: add new MICROPY_GC_SPLIT_HEAP_AUTO "auto grow heap" mode
- profile: remove the requirement to disable MICROPY_COMP_CONST
- mpconfig: enable SSL finalizers if finalizers are enabled
- objstr: fix `str % {}` edge case
- modstruct: support pad bytes in struct format
- dynruntime.h: implement MP_OBJ_NEW_QSTR
- modthread: return thread id from start_new_thread()
- malloc: fix DEBUG_print() args in m_realloc_maybe
- runtime: add helpers to call a general function on nlr jump callback
- parse: always free lexer even if an exception is raised
- persistentcode: always close reader even if an exception is raised
- gc: add "max new split" value in result of gc.mem_free()
- nlrx64: mark nlr_push() as naked function when possible
- mkrules.mk: don't strip binary if STRIP variable is unset
- change ifdef DEBUG_PRINT to if DEBUG_PRINT
- lexer: add missing initialisation for fstring_args_idx

extmod:
- utime_mphal: provide a general mktime function
- modutime: provide a generic time module
- machine_pwm: remove PWM_INIT and PWM_DUTY_U16_NS config options
- network_cyw43: add power management constants
- vfs_lfsx: fix offset used before range check
- extmod.mk: suppress deprecated-non-prototype warning
- moduos: move os.sync() into extmod/moduos.c
- modtimeq: remove timeq module
- btstack: add cmake support for BTstack
- btstack: fix marking of static addresses in set_random_address
- asyncio: rename uasyncio to asyncio
- asyncio/uasyncio.py: add backwards-compatible uasyncio alias
- modbinascii: fix buffer length error
- update to support mbedtls 3.x
- modplatform: set MICROPY_PLATFORM_ARCH on riscv platforms
- modbtree: undefine queue macros before including berkeley-db
- modssl: add SSLContext class
- moddeflate: add deflate module providing the DeflateIO class
- modssl_mbedtls: reference SSLContext from SSLSocket
- vfs_posix_file: add poll support for missing ERR,HUP,NVAL values
- modselect: abstract out a poll_set_t struct and functions
- modselect: factor low-level polling code into common function
- modselect: add optimisation to use system poll when possible
- modselect: remove undocumented support for flags arg to poll
- modssl_mbedtls: reject ioctls that are not supported
- modssl_mbedtls: fix ioctl of a socket in closed/error state
- modselect: properly track number of poll objects that are fd's
- modssl_mbedtls: clear sock member if error creating SSLSocket
- moddeflate: change default window size
- vfs_posix_file: fix flush handling on macOS
- vfs_posix_file: implement sys.std*.buffer objects
- modlwip: add support for SO_BROADCAST socket option
- modsocket: add support for SO_BROADCAST socket option
- modssl_mbedtls: call func psa_crypto_init if PSA is used
- modssl_mbedtls: ignore err ERR_SSL_RECEIVED_NEW_SESSION_TICKET
- modlwip: fix setting of IP option SOF_BROADCAST
- network_esp_hosted: add ESP-Hosted networking interface
- modssl_axtls: only close underlying socket once if it was used
- asyncio/event.py: fix ThreadSafeFlag.ioctl return
- btstack/btstack_hci_uart: trigger a poll after UART data is sent
- asyncio/stream.py: fix cancellation handling of start_server
- modnetwork: increase max hostname length to 32
- modnetwork: forward if.config(hostname) to network.hostname
- vfs_posix_file: fix flush handling in msvc builds

shared:
- upytesthelper: fix spelling of "default"
- libc/printf: fix stdout destination for putchar and puts
- tinyusb: avoid symbol clash on targets with external TinyUSB
- tinyusb: support HS endpoint sizes
- netutils/dhcpserver: reply on correct netif

drivers:
- cyw43: make the CYW43 Bluetooth HCI driver more portable
- esp-hosted: add host driver for ESP-Hosted firmware
- ninaw10/nina_bt_hci: make some minor fixes to HCI driver
- esp-hosted: fix pin IRQ
- esp-hosted: fix MTU size
- esp-hosted: add support for WiFI LED activity indicator

mpy-cross:
- allow specifying source files starting with -
- allow reading from stdin and writing to stdout
- when reading from stdin, write output to stdout
- allow specifying stdin as input without --
- fix source file name in file-not-found error

lib:
- mbedtls_errors: update error list for current version of mbedtls
- mbedtls: update to mbedtls v2.28.1
- mbedtls_errors: add esp32-specific mbedtls error file
- mbedtls_errors: update patch and error list for new mbedtls
- mbedtls: update to mbedtls v2.28.3
- fsp: update FSP for renesas-ra to the latest version v4.4.0
- cyw43-driver: update driver to latest version v1.0.1
- btstack: update to v1.5.6.2
- pico-sdk: update to version 1.5.1
- stm32lib: update library for H5 v1.0.0
- oofatfs: fix speculative read in create_name
- uzlib: add memory-efficient, streaming LZ77 compression support
- uzlib/lz77: always use separate history buffer
- uzlib/defl_static: implement some code size improvements
- uzlib: clean up tinf -> uzlib rename
- uzlib: combine zlib/gzip header parsing to allow auto-detect
- uzlib/tinflate: implement more compact lookup tables
- uzlib/defl_static: optimize zlib_start/finish_block
- uzlib: add a source_read_data var to pass to source_read_cb
- tinyusb: update to the most recent master
- protobuf-c: add protobuf-c library
- cyw43-driver: update driver to latest version v1.0.2
- micropython-lib: update submodule to latest

Support components
==================

docs:
- reference: remove double 'are' in glossary
- update the PWM examples based on recent API improvements
- samd: make use of pin names more consistent in examples
- reference/mpyfiles: add release info on v6.1
- library/espnow: update espnow docs for WLAN.config(pm=x) options
- develop/porting: add missing code to example main.c and Makefile
- reference/speed_python: remove 4-arg limit for viper
- mimxrt: add the pin-out for the Adafruit Metro M7 board
- samd: add the pin-out for the Adafruit Metro M4 Airlift board
- library/index: update built-in extension docs
- reference/packages: add GitHub repo to package example dependency
- reference/mpremote.rst: extend the mpremote guide
- library/index: update docs after umodule rename
- rename uasyncio to asyncio
- esp32: update esp32 docs based on IDF v5 changes
- library/ssl: add documentation for SSLContext
- esp32/quickref: add LAN example for WT32-ETH01 version 1.4
- library/deflate: add docs for deflate.DeflateIO
- develop/gettingstarted: clarify submodule initialization
- develop/gettingstarted: update ARM package list
- library/neopixel: change link to a micropython-lib reference
- library/platform: add docs for the platform library
- library/network: clarify network.hostname() behaviour
- esp32/tutorial: add example for pin access via registers
- library/esp32: update ESP32 idf_heap_info docs to match behaviour
- library/gc: clarify mem_alloc and mem_free only for Python heap
- conf.py: add sphinxcontrib.jquery to extensions
- add requirements.txt file with dependencies for Sphinx
- change remaining "urequests" references to "requests"

examples:
- usercmodule: add a sub-package example
- natmod: rename umodule to module
- hwapi: rename uasyncio to asyncio
- natmod/deflate: add deflate as a dynamic native module
- mark asm, pio, etc. as noqa: F821 (undefined-name)
- hwapi: add missing import for 96Boards Carbon example
- bluetooth: raise ValueError when advertising data is too large
- bluetooth: link to aioble in BLE examples
- natmod: add features4 as a class definition example
- unix/machine_bios.py: fix typo

tests:
- run-tests.py: ensure correct cwd for mpy tests
- basics: add more tests for hashing of various types
- basics: remove __index__ and __inv__ from special methods tests
- import/builtin_ext.py: add test for built-in module override
- import/import_pkg9.py: add test for subpackage attribute
- replace umodule with module everywhere
- run-multitests.py: don't allow imports from the cwd
- run-perfbench.py: don't allow imports from the cwd
- run-natmodtests.py: don't allow imports from the cwd
- float: test domain errors for more combos of args to math funcs
- rename uasyncio to asyncio
- extmod/uctypes_array_assign_le: fix buffer
- extmod/framebuf: fix buffer size issues
- extmod: add tests for ssl.SSLContext
- extmod: add test for passing cadata into ssl.wrap_socket()
- extmod: add deflate.DeflateIO tests
- extmod: add coverage tests for select module
- extmod: skip select/socket tests if they can't create UDP socket
- extmod/select_poll_eintr.py: improve robustness of test
- misc/sys_settrace_features.py: fix to run on newer CPython
- unix/mod_os: make os.system() test work on windows
- run-tests.py: capture output of stderr when running on CPython
- multi_net: increase asyncio tests timeouts
- stress/bytecode_limit.py: reverse order of cases
- float/float_format_ints.py: put power-of-10 test in separate file
- extmod/deflate_decompress.py: skip test when not enough memory
- extmod/ssl_cadata.py: skip test on axtls
- float/math_domain.py: tweak test to also pass with obj-repr-C
- extmod/vfs_fat_finaliser.py: tweak test so files are collected
- README: document ./run-internalbench.py
- run-internalbench.py: remove old CPython reference
- multi_net/ssl_cert_rsa.py: update test certificate
- extmod/asyncio_threadsafeflag.py: update for unix select

tools:
- pyboard.py: rename ProcessPtyToTerminal member "ser" to "serial"
- mpremote: remove unused import of serial
- pyboard.py: import serial.tools.list_ports
- pyboard.py: import errno to fix undefined name in PyboardError
- manifestfile.py: fix license capturing
- mpremote: add repl option to escape non-printable characters
- pydfu.py: use getattr to retrieve getargspec function
- mpremote: add `sleep` command
- mpremote: allow terminator for shortcut commands
- mpremote: add `rtc` commands to get and set the RTC
- mpremote: handle `cp` without destination
- mpremote: detach mpremote from pyboard.py
- mpremote: fix use of stdout_write_bytes function
- mpremote: fix exec_ -> exec in commands.py
- autobuild: update auto-build code to build esp32 port with IDF v5
- autobuild: add support for application .bin files for esp32
- mpy-tool.py: use isinstance() for type checking
- codeformat.py: skip formatting ESP-IDF managed components
- codeformat.py: use pyproject.toml for black config
- mpremote: make soft-reset count as an action
- autobuild: automatically build all variants for each board
- mpy_ld.py: pre-declare some local variables to appease linter
- mpy-tool.py: ignore linter failure in Python 2 compatibility code
- mpy_ld.py: support more complex rodata sections
- metrics.py: fix nrf and rp2 board names after renaming
- autobuild: include .bin firmware in renesas-ra build output
- autobuild/build-downloads.py: verify standard features
- mpremote: add support for rfc2217, serial over TCP
- metrics.py: fix esp32 and esp8266 board names after renaming
- change remaining "urequests" references to "requests"

CI:
- ci.sh: build both SAMD21 and SAMD51 boards as part of samd CI
- ci.sh: add functions to check code spelling using codespell
- ci.sh: add mimxrt and samd ports to code size build
- ci.sh: build PICO_W board as part of rp2 CI
- ci.sh: add a H5 board to stm32 CI build
- ci.sh: add ARDUINO_PORTENTA_C33 to RA CI build
- workflows: fetch full history for mpremote workflow
- workflows: add spell check to code formatting workflow
- workflows: add GitHub Action to lint Python code with ruff
- workflows: force use of Ubuntu-20.04 for unix 32-bit builds
- workflows: update esp32 CI to use IDF v5.0
- workflows: bump actions/checkout from 3 to 4

The ports
=========

all ports:
- use extmod version of mktime instead of port-specific one
- remove os.sync() implementation from stm32 and renesas-ra
- enable os.sync() for esp32, esp8266, rp2, mimxrt, samd51
- standardise docs link in help text
- in machine_i2s.c, rename uasyncio to asyncio
- simplify board feature tags in board.json
- */boards/*/board.json: remove "id" field
- restrict board.json to standard features
- rename Arduino board LED pins to be consistent

bare-arm port: no changes specific to this component/port

cc3200 port:
- mods/modutime: use extmod version of time module
- tools: fix exception raised on process failure
- Makefile: build firmware.zip

embed port: no changes specific to this component/port

esp8266 port:
- modutime: use extmod version of time module
- add support for the Espressif ESP-NOW protocol
- machine_pwm: implement duty_u16() and duty_ns() for consistency
- add support to set/get power saving mode of WLAN
- change network.WLAN from a function to a type
- allow Ctrl-C to interrupt the corrupt-fs while loop
- machine_pin: accept an integer argument to mp_obj_get_pin_obj
- add board variant support
- boards/ESP8266_GENERIC: add image filename
- boards: make sure modespnow.o is placed in irom0
- boards/ESP8266_GENERIC: remove urllib from the 2MiB manifest

esp32 port:
- modutime: use extmod version of time module
- add support for the Espressif ESP-NOW protocol
- add support to set/get power saving mode of WLAN
- change network.WLAN from a function to a type
- boards: add some missing board configs for two UM boards
- esp32_ulp: enable FSM ULP for S2 and S3 chips
- uart: use xtal as UART clock source on S3 and C3
- modespnow: change name of buffer size config option to "rxbuf"
- CMake: change PROJECT_DIR to CMAKE_CURRENT_LIST_DIR
- esp32_ulp: fix ULP (FSM) support for S2 and S3
- allow Ctrl-C to interrupt the corrupt-fs while loop
- switch from UART driver to UART HAL
- ppp_set_auth: add pppapi_set_auth from ESP-IDF
- modesp32: remove esp32.hall_sensor function
- update port to support IDF v5.0.2
- in recv_cb, get espnow rssi from recv_info->rx_ctrl
- network_wlan: wait for WIFI_EVENT_STA_START after activating
- Makefile: provide more IDF shortcuts
- boards: change SDK config parameters from deprecated to new ones
- modules/inisetup.py: format partition as FAT if its label is ffat
- machine_uart: always select a source_clk value in UART config
- re-enable mDNS after move to IDF v5.0.2
- boards/GENERIC_OTA: enable silent checks to reduce firmware size
- network_wlan: wait for STA/AP START/STOP event in wlan.active
- machine_timer: switch from legacy driver to timer HAL
- machine_pin: add a pin-find func and use it in machine_pin_get_id
- use always machine_pin_get_id for getting a Pin id
- add support for board-named pins and the Pin.board dict
- collect properties from IDF-managed components as well
- modmachine: add generic machine.bootloader()
- usb: add custom TinyUSB callback support
- boards/ARDUINO_NANO_ESP32: add support for Arduino Nano ESP32
- CMakeLists: enable multiple extra component directories in build
- boards/ARDUINO_NANO_ESP32: fix deploy instructions
- main: remove unused mbedtls debug function
- machine_wdt: allow feeding WDT from threads
- machine_hw_spi: fix access of SPI(2)
- machine_hw_spi: remove unnecessary duplicate SPI pin defaults
- machine_hw_spi: remove SPI host renaming for C3 and S3 variants
- machine_hw_spi: check for valid SPI id in constructor, not init
- boards: remove references to the IDF version in board.md files
- README: specify that only IDF v5.0.2 is supported
- allow malloc() to allocate from SPIRAM
- enable automatic Python heap growth
- gccollect: make level arg volatile to force recursive function
- Makefile: implement `make submodules` to match other ports
- boards/GENERIC: merge with GENERIC_{SPIRAM,OTA,D2WD,UNICORE}
- boards/GENERIC_C3: merge with GENERIC_C3_USB
- boards/GENERIC_S2: merge with ESP32_S2_WROVER
- boards/GENERIC_S3: merge with GENERIC_S3_{SPIRAM,SPIRAM_OCT}
- partitions.csv: rename to partitions-4MiB.csv
- use uppercase variant names
- Makefile: append board variant to BUILD
- rename GENERIC* boards to ESP32_GENERIC*
- boards/ESP32_GENERIC_C3: enable UART REPL
- modsocket: add support for SO_BROADCAST socket option
- modnetwork: add support for SO_BINDTODEVICE socket option
- support JTAG console, free up UART
- machine_uart: release GIL for blocking reads
- boards: add pins.csv to UM boards and other minor changes
- boards/UM_NANOS3: add new UM NanoS3 board
- network_ppp: block after deleting task
- boards/ARDUINO_NANO_ESP32: clarify recovery instructions
- boards/UM_FEATHERS3: fix I2C pins in pins.csv
- skip validation of image on boot from deepsleep
- machine_pin: fix null pointer access in machine_pin_find
- mphalport: add function/line/file info to check_esp_err exception
- fix Partition.writeblocks() partial write corruption
- boards: fix VBAT voltage calculation for UM S3 boards
- boards: add bootloader rollback support for all builds
- main: allow a board to override the MicroPython task stack size
- boards/ARDUINO_NANO_ESP32: use Arduino USB IDs
- boards/manifest.py: freeze aioespnow into firmware by default

mimxrt port:
- modutime: use extmod version of time module
- machine_pwm: start PWM only if freq and duty are set
- flash: separate low level driver code from flash object
- mpconfigport: add back lost uos.urandom()
- add missing UART defintion and remove obsolete config
- machine_spi: ignore transfers with len=0
- machine_pin: perform full configuration in machine_pin_set_mode
- sdcard: fix GCC 13 build error with sdcard_cmd_set_bus_width
- led: add support for up to four LEDs
- boards/ADAFRUIT_METRO_M7: add Adafruit Metro M7 board definition
- machine_pwm: fix freq change, PWM print, and error checks
- Makefile: use a specific fsl_flexspi_nor_boot.c for mimxrt1062
- machine_pin: fix bug when Pin.irq is called without a handler
- hal/pwm_backport: fix 0 and 65536 edge cases of PWM's duty_u16
- machine_uart: add uart.deinit method and machine_uart_deinit_all
- machine_uart: add support for UART hardware flow control
- boards: add support for GPIO control of SNVS pins
- hal: make flash clock frequency configurable
- fix UART RTS/CTS assignments for the OLIMEX and Adafruit boards
- machine_pin: extend pin configuration functions
- sdio: add SDIO driver
- integrate support for WiFi via the CYW43 driver
- integrate Bluetooth support with NimBLE bindings
- irq: move all IRQ related definitions to dedicated header
- machine_uart: fix and complete UART.deinit and uart_deinit_all
- boards: fix use of MICROPY_HW_SDRAM_AVAIL in MIMXRT1176.ld
- machine_uart: support slow baud rates for UART
- machine_uart: add a helper function to change the baudrate
- sdio: move config guard so headers are only included if used
- Makefile: update to work with latest TinyUSB
- mpconfigport: don't override parse chunk alloc
- sdio: add support for the 117x series
- mimxrt_sdram: allow boards to override the default SDRAM config
- Makefile: enable the FSL USDHC for supported MCU series
- remove SDCARD Makefile config option
- mpbthciport: enable flow control for BT HCI UART
- mbedtls: enable certificate validity time validation
- machine_uart: set the UART clock to a fixed 40MHz value
- boards/MIMXRT1176_clock_config: fix comments about UART clocks
- boards: fix naming of SD-card config option
- mpbthciport: allow disabling UART flow control for BLE
- machine_rtc: improve the RTC init at boot

minimal port: no changes specific to this component/port

nrf port:
- modules/utime: use extmod version of time module
- boards: rename all nRF boards to use uppercase

pic16bit port: no changes specific to this component/port

powerpc port:
- mpconfigport: don't override parse chunk alloc

qemu-arm port: no changes specific to this component/port

renesas-ra port:
- change MICROPY_HW_BOARD_NAME definition to product name
- modutime: use extmod version of time module
- update boards and ra directory files to support FSP v4.4.0
- add a macro definition to avoid compile error of FSP v4.4.0
- irq: fix typo in comment about IRQ priorities
- consolidate hal_entry.c code and remove hal_entry() func
- boards/make-pins.py: fix PA/PB pins support
- consolidate all fsp_cfg header files to one location
- support changing baudrate for UART
- add support for RA6M5, and add machine PWM, DAC, SDCard
- boards/VK_RA6M5: add new board definition
- remove duplicate machine module from constants list
- machine_spi: consistently use machine_pin_find to get pin
- boards: remove unreachable code in make-pins.py
- Makefile: generate binary firmware output
- add TinyUSB support
- add Bluetooth support using NimBLE
- add RNG driver
- add networking support using lwIP
- add mbedTLS support
- fsp_cfg: add common FSP config files
- boards/ARDUINO_PORTENTA_C33: add support for Portenta C33
- boards/ARDUINO_PORTENTA_C33: update WiFi config
- tune lwip buffers and timing to improve network performance

rp2 port:
- modutime: use extmod version of time module
- machine_pwm: enable keyword args in constructor and add init method
- machine_pwm: add support for inverting a PWM channel output
- machine_pwm: add duty_x() checks and return 0 if PWM is not started
- make rp2_state_machine_exec accept integers
- CMakeLists: allow relative MICROPY_BOARD_DIR when invoking cmake
- mphalport: only use CYW43 MAC for WLAN0 interface
- CMake: normalize MICROPY_PORT_DIR
- add Bluetooth support via cyw43
- mpbthciport: cancel existing alarms
- boards/PICO_W: enable Bluetooth Low Energy support
- machine_pin: factor out pin-find code from machine_pin_make_new
- use uppercase variant names
- Makefile: append board variant to BUILD
- rename PICO, PICO_W to RPI_PICO, RPI_PICO_W
- machine_timer: fix printing of timer period
- mpbthciport: switch to static scheduler nodes
- mpbthciport: fix HCI UART config
- mpconfigport: disable BLE locking when MICROPY_PY_BLUETOOTH enabled
- boards/ARDUINO_NANO_RP2040_CONNECT: use standard HCI UART baudrate
- modmachine: fix lightsleep while wifi is powered off
- msc_disk: allow configuring the USB MSC inquiry response
- README: fix name of RPI_PICO_W board
- CMakeLists: enable debug symbols in all builds
- implement time.time_ns with time_us_64 so it has us resolution

samd port:
- modutime: use extmod version of time module
- machine_pwm: add init() method to PWM and simplify the PWM code
- mpconfigport: drop support for SoftSPI max speed
- boards/MINISAM_M4: update pins.csv for the Mini SAM M4 board
- rearrange the MCU-specific loader files
- mcu/samd51: enable MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF
- boards: add default deploy instructions
- main: fix sercom deinit ordering in soft-reset
- modmachine: add machine.deepsleep as alias of machine.lightsleep
- modmachine: make some machine classes configurable by #defines
- boards/SEEED_WIO_TERMINAL: rename two pins starting with a digit
- mcu: reduce the startup time after hard reset
- machine_uart: add support for UART hardware flow control
- boards/ADAFRUIT_METRO_M4_EXPRESS: add Metro M4 Express Airlift
- boards: rename flash pins consistently for QSPI and SPI
- samd_spiflash: add SPI flash driver and configure it accordingly
- samd_qspiflash: add QSPI flash driver and configure it accordingly
- adapt existing samd.Flash and integrate with (Q)SPI flash in boot
- boards: extend the code size limit for boards with external flash
- set the LFS type in mpconfigmcu.mk instead of mpconfigboard.mk
- Makefile: move the math lib files from mpconfigmcu.mk to Makefile
- Makefile: print memory region usage instead of totals
- mpconfigport: enable DHT and onewire drivers on all MCUs/boards
- mpconfigport: provide the platform module
- modules/_boot.py: add /lib to sys.path
- mpconfigport: don't override parse chunk alloc

stm32 port:
- modutime: use extmod version of time module
- boards/ARDUINO_PORTENTA_H7: enable FDCAN
- boards/stm32h723_af.csv: fix ADC AF definitions
- mboot: fix alignment of packed final buffer
- irq: fix typo in comment about priorities
- usb: fix USB support on STM32G4
- boards/NUCLEO_G474RE: make it easier to enable USB
- adc: add support for STM32L4A6 MCUs
- boards/NUCLEO_L4A6ZG: add new board definition
- help: don't include unavailable features in help()
- help: exclude legacy entries from help, and adjust constant names
- mpconfigboard_common: provide default spidev config
- boards: use default spibdev config where appropriate
- Makefile: pass relevant CPU flags to assembler
- make-stmconst.py: support structs with names ending in _t
- main: start UART REPL as early as possible
- usbd_conf: treat G0 USB periph as MICROPY_HW_USB_IS_MULTI_OTG=0
- machine_adc: handle ADC resolution less than 8 bits on all MCUs
- add initial support for H5 MCUs
- boards: add ld, af.csv and hal_conf_base.h files for H5 MCUs
- octospi: add preliminary support for OCTOSPI peripheral
- boards/STM32H573I_DK: add H5 board definition files
- add USB support for STM32L1 MCUs
- modify RCC->APB2ENR directly instead of HAL API
- modmachine: remove duplicate machine_timer_type declaration
- modmachine: make machine_reset_cause_obj public
- dac: fix dac.write_timed on G4 MCUs to use 32-bit DMA access
- adc: fix ADC clock prescaler for G4 MCUs
- adc: fix pyb.ADCAll.read_core_temp for G4 MCUs
- adc: fix reading internal ADC channels on G4 MCUs
- machine_adc: fix machine.ADC to work on G4 MCUs
- adc: add workaround for ADC errata with G4 MCUs
- adc: fix pyb.ADCAll.read_core_bat on G4 and L4 MCUs
- qspi: allow qspi_write_cmd_data to write cmd with 1 data byte
- mpconfigport: always define MICROPY_SOFT_TIMER_TICKS_MS
- remove duplicate machine module from constants list
- boards/B_L072Z_LRWAN1: add pin definitions for internal SX1262
- boards/B_L072Z_LRWAN1: lower default ROM level to "Core"
- spi: add STM32WL5 SUBGHZ SPI peripheral
- powerctrlboot: support STM32WL system clock from HSE+PLL
- dma: fix DMA completion on WL55 boards
- subghz: add STM32WL55 subghz radio interface to stm module
- modstm: add MICROPY_PY_STM_CONST flag, clear it for STM32WL5
- use uppercase variant names
- Makefile: append board variant to BUILD
- mboot: fix fwupdate by replacing zlib with new deflate module
- uart: fix UART timeout issue with low baudrate on G4 MCUs
- timer: fix deadtime config on Advanced Timer peripherals
- dma: add support for SPI1 DMA on H5 MCU's
- octospi: add support for dual-line SPI interface
- powerctrlboot: allow using PLL3 for USB clock on H5 MCU's
- timer: fix use of TIM8 on H5 MCU's
- uart: add support for UART10 when it's a USART
- powerctrlboot: allow PLL1 Q and R outputs to be enabled on H5
- adc: fix STM32H5 support
- adc: add support for STM32H5 ADC2 inputs
- adc: optimize sampling time for G4, H5, L4 and WB MCUs
- machine_adc: fix and improve STM32H5 support
- dac: add STM32H5 DAC support, with dma_nohal implementation
- boards: move includes to after defines in all hal_conf.h files
- uart: generalise UART source clock calculation for H5 and H7 MCUs
- dma: remove unbalanced )
- usbd_msc_interface: allow configuring the MSC inquiry response
- boards/ARDUINO_GIGA: update board config
- i2c: add support for I2C4 on H7 MCUs

teensy port: no changes specific to this component/port

unix port:
- modutime: use extmod version of time module
- Makefile: allow variants to add QSTR_DEFS
- main: add NLR scope for checking module __path__
- README: fix Markdown link markup
- modsocket: add poll support for missing ERR,HUP,NVAL poll values
- modselect: remove unix-specific implementation of select module
- modjni: fix build errors with type definitions and error strings
- main: fix memory leakage if MICROPY_USE_READLINE is disabled

webassembly port:
- modutime: use extmod version of time module
- make mp_js_do_str asynchronous
- make mp_js_process_char asynchronous
- replace typeof window check with ENVIRONMENT_IS_NODE flag

windows port:
- Makefile: allow variants to add QSTR_DEFS

zephyr port:
- modutime: use extmod version of time module

New mip package manager, compressed type structs and Pico W support

This release of MicroPython introduces a new lightweight package manager
called mip, which uses a custom protocol to query and install packages that
is optimised for embedded systems.  It is intended to take over the role of
upip and supports installing packages from micropython-lib as well as any
URL.  Mip can be run directly on a device (with network connectivity) or
via mpremote.  As part of this, all pure-Python drivers have been moved
from the micropython repository to the micropython-lib repository, making
it easier to install the packages needed for a given project.

In the MicroPython runtime, core/built-in types have been compressed by
only including in the C-level type struct as many slots for C function
pointers as is needed for a given type (instead of storing NULL pointers
for unused slots).  This resulted in a reduction of code size of many
kilobytes for all ports (eg around 1200 for bare-arm) with a very minimal
loss in performance.  Any third-party C extensions will need to be updated
to work with this change.  See commits
662b9761b37b054f08fe2f7c00d0fce3a418d0b0 and
3ac8b5851e5f4dade465d52b91ed2ccc17851263 for details.

The MicroPython VM/runtime has also seen many improvements and bug fixes,
including: addition of hex/fromhex methods to bytes/memoryview/bytearray,
dictionary union (PEP 584), support for __float__ and __complex__
functions, support for __dict__ on module objects and UTF-8 validation of
all strings.  Whole number floats are now formatted exactly, and there have
been other accuracy improvements to parsing and formatting of floats.
A sub-version has been introduced for .mpy files which is used only when a
.mpy file includes native code, allowing the native ABI to change while
retaining backwards compatibility with pure bytecode .mpy files.
There is now an option to have the GC heap split across more than one pool
of memory, although this is not yet in use by the ports.  And root pointer
registration has been simplified with the new MP_REGISTER_ROOT_POINTER
macro.

In the network module, the keyword arguments to scan(), connect() and
config() have been renamed to be more consistent across ports and drivers.
The changed argument names are: "essid" changed to "ssid", "auth" or
"authmode" changed to "security", and "password" changed to "key".  The old
keyword arguments are still supported so this change is backwards
compatible.  The functions network.hostname() and network.country() have
also been added and provide a standard interface across ports to set the
global networking configuration for all interfaces and interface types.  In
particular, setting the hostname is now supported for all CYW43xx-based
boards (pyboard-D, Arduino Portenta, Pico W, and others).

The mbedtls (SSL library) settings have also been unified across ports that
use this library and enable elliptic curve DH and DSA cryptography enabled
so that devices can connect to more websites.  The cert_reqs and cadata
arguments have also been implemented.  Sockets now support leaving
multicast groups.  WebREPL will now run the page from the device, allowing
WebREPL resources to load from a HTTPS site.

The bluetooth module has a minor breaking change for
IRQ_GATTC_CHARACTERISTIC_RESULT: def_handle has been replaced with
end_handle.  This is not expected to affect most programs as def_handle is
unlikely to be used.  See commit cacc96d98c2a70dc7e5194331ea70746c39746ec.

The uasyncio module now supports stream read(-1), handles gather with no
awaitables, and adds a clear() method to ThreadSafeFlag.  The framebuf
module adds ellipse and polygon drawing methods, and a fill argument to
rect() for consistency with those new methods.

A new port has been added, the "embed" port, which is a port of MicroPython
that targets the C language and outputs a set of self-contained .c and .h
files for embedding into a wider project.  An example is provided to show
how this works.

The esp8266 port has reverse-special-methods enabled on the GENERIC board,
uart.flush() and uart.txdone() added, real open drain output enabled on
pins driven by PWM, and adds the ability to set TX power for the WLAN
interface.

The esp32 port now uses synchronous BLE events which allows support for BLE
pairing and bonding.  The LAN driver adds support for LAN8710, KSZ8081,
configuration of ETH ref_clk pin, and support for SPI-based Ethernet chips.
UART now supports setting timeout_char and implements uart.flush() and
uart.txdone().  New boards include ESP32S3 with octal SPIRAM, Olimex PoE
boards and a generic board for unicore chips.  There have also been many
bug fixes, in particular for newer MCU versions such as S2, S3 and C3.

The mimxrt port has seen a lot of clean up of the code, support for
MIMXRT1176 MCUs and the MIMXRT1170_EVK board, a soft-timer implementation
of machine.Timer, addition of machine.bootloader(), as well as uart.flush()
and uart.txdone().

On the nrf port, machine.UART and machine.PWM have been improved to match
other ports (the PWM change is a breaking change), and machine.I2C now
supports the freq argument.  New boards include the Arduino Nano 33 BLE
sense board and the Seeed XIAO NRF52840 Sense.

The rp2 port sees the integration of the CYW43xx WiFi driver which is used
in the new Pico W board, a board similar to the Pico but with WiFi support.
Other new boards include W5500_EVB_PICO, WEACTSTUDIO and the nullbits Bit-C
PRO board.  Support has been added for named pins, including Pin.board and
Pin.cpu attributes, consistent with other ports that support this feature.
The machine.lightsleep() function has been implemented, along with SSL
certificate time validation, and more accurate formulas are used to
determine PWM frequency and duty.  The GC heap available to MicroPython
programs has been increased to use the maximum available free RAM, adding
about 20k to the user heap.  There have also been important bug fixes to
threading and concurrency when using both cores.

The samd port has been significantly extended to include: named pins with
a pins.csv file, and Pin.board and Pin.cpu attributes; ADC, PWM, DAC,
SoftSPI, SoftI2C, SPI, I2C and RTC classes added to the machine module;
pin.irq() method and OPEN_DRAIN mode for pins; freq, disable_irq,
enable_irq, idle, lightsleep and time_pulse_us functions added to the
machine module.  Floating point support has been added for SAMD21 devices,
and the math module enabled for SAMD51.  A board definition for Sparkfun
Think Plus has been added.

The stm32 port sees support added for STM32L1xx MCUs, STM32H723, USB on
STM32G0xx and mboot support for STM32G0xx.  The existing CYW43xx WiFi
driver has been replaced with the open-source version of cyw43-driver and
this has been integrated with all existing boards with CYW43xx chips.
Support for the CC3000 WiFi driver has been removed, and the Wiznet driver
integration has been reworked to use the generic one shared with other
ports (and also uses lib/wiznet5k instead of the old drivers/wiznet5k).
Hardware I2C implementation has been added for STM32L1xx and STM32L4xx,
support added for Arduino 1200bps touch to enter the bootloader (only on
Arduino boards), mbedtls (SSL) certificate time validation added, and
link-time-optimisation (LTO) enabled by default on boards with small flash
size.  New board definitions include: LEGO Hub No. 7, NUCLEO-L152RE,
NUCLEO-F756ZG, NUCLEO-H723ZG, Arduino Nicla Vision and Arduino Giga H7.
Arduino boards also now include a range of frozen libraries including
senml.

For the unix and windows ports, build outputs (including executables) are
now kept inside the $(BUILD) directory associated with the build.  As part
of this the variant suffix has been removed from the executable name.  For
example, what was micropython-coverage is now build-coverage/micropython,
and the standard variant is build-standard/micropython.  Furthermore, the
dev variant has been removed and its features enabled instead on the
standard variant, which now enables the same feature set as a typical
bare-metal board, making it more convenient to use for development.  The
remaining variants are: minimal, standard, nanbox, coverage.  The SSL
implementation for this port has switched from axtls to mbedtls, again to
match most bare-metal ports.

The javascript port has been renamed to the webassembly port, and adds
support for VFS and VfsPosix using Emscripten's POSIX filesystem layer.
The way stdout printing works has also changed to dispatch via a custom
event called "micropython-print".

The zephyr port upgraded Zephyr to v3.1.0, added custom configuration for
bbc_microbit_v2, and enabled finalisers.

The change in code size since the previous release for various ports is
(absolute and percentage change in the text section):

       bare-arm:   -1124  -1.934%
    minimal x86:   -4322  -2.967%
       unix x64: +264181 +50.533% standard
          stm32:   -3592  -0.906% PYBV10
         cc3200:   -1832  -0.990%
        esp8266:   -2284  -0.327% GENERIC
          esp32:   +9659  +0.632% GENERIC
            nrf:     -84  -0.045% pca10040
            rp2:  +13096  +4.291% PICO
           samd: +127776 +90.488% ADAFRUIT_ITSYBITSY_M4_EXPRESS

The changes that dominate these numbers are:
- bare-arm, minimal, stm32, cc3200, esp8266: reduced size due to compressed
  type structs
- unix: switching axtls for mbedtls, merging in dev configuration options
  and features
- esp32: new Ethernet drivers and some additional machine module
  functionality
- nrf: compressed type struct and machine module improvements
- rp2: additional mbedtls features and ciphers
- samd: many new features, and machine module classes and functions

Thanks to everyone who contributed to this release:
Alex Riesen, Andrew Leech, Andrew Scheller, Angus Gratton, Antonello
Margottini, Antonin ENFRUN, Ayke van Laethem, Blake Felt, brave ulysses,
Brian Cooke, Brian Pugh, Carlosgg, Chris Overgaauw, Chris Swan, Chris
Waggoner, chrismas9, Christian Clauss, Christian Walther, Clayton Cronk,
cpottle9, Dale Weber, Damiano Mazzella, Damien George, Damien Tournoud, Dan
Ellis, Daniel Jour, David (Pololu), David Grayson, David Lechner, David
Peake, David Yang, Dorukyum, Efi Weiss, enriquezgarc, Felix Dörre, Florian
Weimer, glenn20, hoihu, Howard Lovatt, iabdalkader, Ian Davies,
IcedRooibos, Ihor Nehrutsa, Jacob Siverskog, Jan Hrudka, Jan Willeke, Jared
Hancock, Jatty_, Jay Greco, Jeff Epler, Jeremy Rand, Jim Mussared, Jonas
Scharpf, Jos Verlinde, Juan Francisco Cantero Hurtado, Koen De
Vleeschauwer, Kyuchumimo, Lars Haulin, Laurens Valk, LiaoJingyi_winY7kp,
Luiz Brandao, ma-lalonde, manobendro, Maripo GODA, Mark Grosen, Martin
Milata, Mat Booth, Matt Trentini, Maureen Helm, Michael Bentley, Michael
Mogenson, MrJake222, Nathan Hendler, Ned Konz, Nicholas H.Tollervey, Oliver
Joos, omogenot, Patrick, Patrick Joy, Paul Grayson, Paul Warren, Pepijn de
Vos, Peter Harper, Peter Hinch, PGE, Phil Howard, Philip Peitsch, Philipp
Ebensberger, pmendham, Rayane Chatrieux, Red_M, Rob Knegjens, robert-hh,
Sebastian Romero, Simon Arlott, Sky, Stewart C. Russell, Stig Bjørlykke,
stijn, Stuart Langridge, Takeo Takahashi, Thorsten von Eicken, Tim Gates,
Tobias Thyrrestrup, Tomasz 'CeDeROM' CEDRO, Tomofumi Inoue, TPReal,
Trammell hudson, Wind-stormger, yn386, Yonatan Goldschmidt, 小权一句两句.

The work done in this release was funded in part through GitHub Sponsors,
by George Robotics, and by Planet Innovation.

What follows is a detailed list of changes, generated from the git commit
history, and organised into sections.

Main components
===============

all:
- fix paths to mpy-cross and micropython binaries
- remove MICROPY_PY_IO_FILEIO config option
- update all manifest.py files to use new features
- simplify buffer protocol to just a "get buffer" callback
- standardise mp_obj_type_t initialisation
- make all mp_obj_type_t defs use MP_DEFINE_CONST_OBJ_TYPE
- fix #if inside MP_DEFINE_CONST_OBJ_TYPE for msvc
- remove unnecessary locals_dict cast
- use += rather than = everywhere for CFLAGS/LDFLAGS/LIBS
- keep msvc build output in build/ directories
- fix Python comparison to None and True, and use "not in"
- use micropython-lib unconditionally in manifests
- replace upip with mip everywhere
- update Python formatting to black "2023 stable style"
- update copyright year range to include 2023

py core:
- vm: change comparison for finally handler search from > to >=
- emit: remove logic to detect last-emit-was-return-value
- emit: suppress unreachable bytecode/native code that follows jump
- objcell: make cell get/set funcs static-inline to reduce code size
- parsenum: support parsing complex numbers of the form "a+bj"
- parsenum: fix parsing of complex "j" and also "nanj", "infj"
- parsenum: optimise when building with complex disabled
- objclosure: forward function attributes for closures
- objfun: support function attributes on native functions
- builtin: remove unnecessary module declarations
- builtinhelp: don't show help for an MP_MODULE_ATTR_DELEGATION_ENTRY
- mkrules.cmake: improve printing of git-submodules error
- scheduler: de-inline and fix race with pending exception / scheduler
- vm: document internal SELECTIVE_EXC_IP option
- emitnative: fix STORE_ATTR viper code-gen when value is not a pyobj
- vm: remove check for ip being NULL when handling StopIteration
- vm: in YIELD_FROM opcode, expand helper macros and remove them
- vm: consistently indent #if guards to match the code they surround
- objnamedtuple: fix segfault with empty namedtuple
- misc: add MP_STATIC_ASSERT_NOT_MSC()
- obj: add static safety checks to mp_obj_is_type()
- obj: add debug-only runtime checks to mp_obj_is_type()
- make_root_pointers: add MP_REGISTER_ROOT_POINTER parser/generator
- mpstate: drop MICROPY_PORT_ROOT_POINTERS from mp_state_vm_t
- persistentcode: use MP_REGISTER_ROOT_POINTER()
- modsys: use MP_REGISTER_ROOT_POINTER()
- scheduler: use MP_REGISTER_ROOT_POINTER()
- misc: fix msvc compilation with compressed error messages
- qstr: make mp_decompress_rom_string decl and def the same
- gc: allow the GC heap to be split over multiple memory areas
- gc: reduce code size when MICROPY_GC_SPLIT_HEAP is disabled
- obj: add support for __float__ and __complex__ functions
- obj: make mp_obj_get_complex_maybe call mp_obj_get_float_maybe first
- compile: support large integers in inline-asm data directive
- modio: remove FileIO and TextIOWrapper from io module
- formatfloat: format all whole-number floats exactly
- builtinimport: remove duplicate static function argument
- mkenv.mk: use micropython-lib from submodule by default
- runtime: fix crash in star arg unpacking
- mpprint: fix formatting typo with mp_print_ext_t struct name
- objstr: reformat str access macros to make them readable
- mkrules.mk: keep all build artefacts inside $(BUILD) directory
- dynruntime.mk: allow building assembly source in natmods
- nlrpowerpc: fix generation of ppc64 code on ppc32 build
- qstr: change qstr hash type from mp_uint_t to size_t
- objstr: consolidate methods for str/bytes/bytearray/array
- objstr: add hex/fromhex to bytes/memoryview/bytearray
- objstr: remove str function object declarations from header file
- mkrules: use abspath to find directory for mpy-cross dependency
- parsenum: ensure that trailing zeros lead to identical results
- formatfloat: use pow(10, e) instead of pos/neg_pow lookup tables
- dynruntime: add mp_obj_is_true
- clean up formatting of union definitions
- builtinimport: allow overriding of mp_builtin___import__
- objstr: split mp_obj_str_from_vstr into bytes/str versions
- objstr: always ensure mp_obj_str_from_vstr is unicode-safe
- objstr: optimise mp_obj_new_str_from_vstr for known-safe strings
- objstr: always validate utf-8 for mp_obj_new_str
- persistentcode: clarify ValueError when native emitter disabled
- objpolyiter: add a new polyiter type with finaliser support
- mpconfig: add LFS1/LFS2 options to match FAT/posix
- mpconfig: make feature levels available to mpconfigport.h
- mpconfig: add "everything" features from unix coverage
- objpolyiter: fix comment about finaliser method
- mkrules.mk: add link to build troubleshooting on failure
- obj: add macro to declare ROM mp_obj_type_t instances
- objexcept: make MP_DEFINE_EXCEPTION use MP_DEFINE_CONST_OBJ_TYPE
- obj: add "full" and "empty" non-variable-length mp_obj_type_t
- obj: add accessors for type slots and use everywhere
- obj: add slot-index mp_obj_type_t representation
- obj: remove basic mp_obj_type_t sparse representation
- objtype: optimise slot RAM usage for instance types
- objnamedtuple: optimise slot RAM usage for namedtuple
- obj: merge getiter and iternext mp_obj_type_t slots
- obj: convert make_new into a mp_obj_type_t slot
- obj: optimise code size and performance for make_new as a slot
- persistentcode: introduce .mpy sub-version
- objmodule: add support for __dict__
- runtime: add mp_raise_OSError_with_filename helper function
- include filename in errors from loading/saving files via "open"
- parse: allow const types other than int to optimise as true/false
- objstr: don't treat bytes as unicode in str.count
- mkenv.mk: make CPP definition explicit for consistency
- objstr: add a helper to set mp_obj_str_t data
- modsys: add support for sys.executable
- py.mk: make user-C-module handling self-contained in py.mk
- misc: remove use of bitfield from vstr_t
- obj: verify floating point type is correct for repr C
- persistentcode: only emit sub-version if generated code has native
- obj: add comments explaining the slot index scheme
- makeversionhdr: fall back to py/mpconfig.h instead of docs/conf.py
- builtinimport: fix crash handling "weak link" module names
- objarray: detect bytearray(str) without an encoding
- emitnative: ensure load_subscr does not clobber existing REG_ARG_2
- nlrmips: add native NLR support for MIPS architecture
- makeversionhdr.py: allow running outside of repo
- objdict: implement dictionary union (PEP 584)
- bc: fix checking for duplicate **kwargs
- modmicropython: make module optional
- mpconfig: include micropython module in core features
- remove the word "yet" from exception messages
- pass in address to compiled module instead of returning it
- gc: avoid valgrind false positives
- gc: ensure a gap of one byte after the ATB
- gc: fix debug printing of GC layout
- obj: remove unused MP_DEFINE_CONST_OBJ_FULL_TYPE macro
- emitnative: initialise locals as Python object type for native code
- map: clear value when re-using slot with ordered dictionaries
- gc: increase the address length in gc_dump_alloc_table()
- objarray: raise error on out-of-bound memoryview slice start
- lexer: wrap in parenthesis all f-string arguments passed to format
- add parenthesis to default impl of MP_OBJ_TO_PTR, MP_OBJ_FROM_PTR
- objint_mpz: catch and reject @ and @= operating on big integers
- mkrules: support mpy-tool-flags in cmake frozen code generation
- mkrules.cmake: force build mpversion.h and frozen_content.c
- modmath: fix two-argument math function domain check
- emitnative: explicitly compare comparison ops in binary_op emitter
- makeversionhdr.py: optionally get git tag and git hash from env vars
- compile: fix scope of assignment expression target in comprehensions
- gc: make gc_dump_info/gc_dump_alloc_table take a printer as argument
- mpconfig: provide config option for internal printf printer
- builtinimport: fix unix port build with external imports disabled
- makeversionhdr.py: always add micro to version string even if it's 0
- obj: add MP_NOINLINE to mp_obj_malloc_helper
- mpstate: add mp_thread_is_main_thread() helper macro
- scheduler: implement VM abort flag and mp_sched_vm_abort()
- obj: fix spelling of staticmethod
- makeqstrdefs.py: fix handling GreenHills C/C++ preprocessor output

extmod:
- network_cyw43: rename WLAN keyword args to ssid/security/key
- network_ninaw10: rename WLAN connect argument from essid to ssid
- modlwip: clean up inclusion of modlwip in build process
- extmod.cmake: only include modbtree in build if it's enabled
- extmod.mk: separate out extmod file list from py.mk to extmod.mk
- modbtree: use buffer protocol for keys/values
- uasyncio: attempt to write immediately in Stream.write method
- uasyncio: implement stream read(-1) to read all data up to EOF
- vfs: prevent uninitialized variable warning for path_out
- network_cyw43: support new cyw43-driver
- modnetwork: include cyw43-driver header if it's enabled
- network_cyw43: add "security" config option to get/set auth mode
- btstack: use MP_REGISTER_ROOT_POINTER()
- nimble: use MP_REGISTER_ROOT_POINTER()
- modnetwork: use MP_REGISTER_ROOT_POINTER()
- uos_dupterm: use MP_REGISTER_ROOT_POINTER()
- modlwip: use MP_REGISTER_ROOT_POINTER()
- vfs: use MP_REGISTER_ROOT_POINTER()
- modbluetooth: use MP_REGISTER_ROOT_POINTER()
- always use custom mbedtls error message code
- modussl_mbedtls: implement cert_reqs and cadata arguments
- btstack: fix descriptor discovery handle range and events
- network_ninaw10: move ninaw10 root pointer registrations here
- modbluetooth: add support for running sync irq on system thread
- webrepl: allow the page to run from the device (over HTTP)
- uasyncio: handle gather with no awaitables
- ntptime: factor out ntptime module from esp8266 port
- modussl_mbedtls: set a more sensible default debug log level
- network_cyw43: add hostname config option
- network_wiznet5k: register NIC when the lwIP stack is used
- network_wiznet5k: drop obsolete argument count check
- network_wiznet5k: deinit the NIC before (re-)initialisation
- network_wiznet5k: schedule clearing of interrupt flags
- network_wiznet5k: rearrange the function wiznet5k_poll()
- network_wiznet5k: extract SPI transfer function dynamically
- uasyncio: add clear method to ThreadSafeFlag
- uasyncio: rename internal _flag to state, to save a qstr
- modlwip: add support for leaving multicast groups
- vfs_posix_file: remove unused MICROPY_VFS_POSIX_FILE
- modframebuf: optimise argument handling
- modframebuf: add fill argument to rect()
- modframebuf: add ellipse drawing method
- modframebuf: add polygon drawing methods
- modframebuf: improve poly-fill boundary pixels
- network_wiznet5k: use the configured DNS address if available
- machine_i2c: call MICROPY_PY_EVENT_HOOK during i2c.scan()
- modure: convert byte offsets to unicode indices when necessary
- modbluetooth: fix descriptor registration with empty tuple
- modbluetooth: replace def_handle with end_handle in char IRQ
- vfs: add finaliser to ilistdir to close directory handle
- vfs_posix_file: implement finaliser for files
- modbluetooth: change data_len type from size_t to uint16_t
- modbluetooth: do GATTC reassembly in protected uPy context
- modbluetooth: run BLE IRQ callback in protected NLR context
- extmod.mk: make extmod.mk handle GIT_SUBMODULES
- make extmod.mk self-contained
- utime_mphal: make ticks_add check for overflow of delta
- btstack: update BTstack bindings to work with latest BTstack
- mbedtls: add common configuration file, and use it in all ports
- mbedtls: enable MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE
- mbedtls: enable elliptic curve DH and DSA cryptography
- mbedtls: remove MBEDTLS_ECP_DP_CURVE25519_ENABLED config
- mbedtls: remove brainpool curves from config
- machine_timer: move stm32's implementation of machine.Timer here
- vfs_posix: include errno.h and unistd.h headers
- extmod.cmake: allow overriding the default MBEDTLS_CONFIG_FILE
- modlwip: use actual errno in exception for error in listen
- extmod.mk: set default mbedtls config file in extmod Makefile
- btstack: allow the BTstack config to be overridden by a board
- add and reorganise compilation guards and includes
- extmod.cmake: add MICROPY_PY_BTREE compiler definition
- moduplatform: remove _M_IX86 test for xtensa
- moduplatform: fix MSVC x86_64 check
- modframebuf: fix crash in FrameBuffer scrolling beyond extents
- uasyncio: fix syntax of generator functions
- modnetwork: use a type protocol to implement NIC functions
- modussl_mbedtls: fix support for ioctl(MP_STREAM_POLL)
- network_cyw43: fix handling of networks with open security
- axtls-include: add back needed header files for building axTLS
- utime_mphal: fix comment re delta range check in time_ticks_add
- modbtree: move system includes within MICROPY_PY_BTREE guard
- modnetwork: add network.hostname() and network.country()
- modnetwork: allow more extensive port-specific customisation
- network_cyw43: use CYW43_CHANNEL_NONE for default arg in connect
- vfs_posix: do not filter '..*' in ilistdir when filtering '..'
- network_ninaw10: check socket types when creating new sockets
- network_cyw43: fix setting hostname using config() method
- network_cyw43: add support to get STA RSSI using status() method
- network_ninaw10: add missing raw socket type to socket()
- btstack: switch to use hci_dump_init instead of hci_dump_open
- modbluetooth: merge gatts_notify/indicate implementation
- btstack: fix indicate/notify queuing
- btstack: include value handle in client read/write events
- btstack: fix MTU handling
- btstack: add support for CCCD to allow client subscriptions
- nimble: fix flags for descriptor registration
- modbluetooth: make all HCI transports trace in the same format
- btstack/modbluetooth_btstack: add default services

shared:
- runtime/tinyusb_helpers: add TinyUSB helper functions
- netutils/dhcpserver: match default DNS to server IP
- readline: use MP_REGISTER_ROOT_POINTER()
- runtime/pyexec: use MP_REGISTER_ROOT_POINTER()
- runtime/softtimer: move softtimer.[ch] to shared/runtime
- runtime/softtimer: remove obsolete #include statement
- runtime/sys_stdio_mphal: make func static and remove some TODOs
- runtime/gchelper_native: fix pointer cast on x86_64
- netutils: add "py/obj.h" header include
- tinyusb: create common TinyUSB code for reuse by ports
- tinyusb: further refactor static USB device implementation
- tinyusb: fix CDC bNumInterfaces value
- runtime: use mp_printf consistently, instead of printf
- runtime/gchelper: drop cpu directive from ARM asm helpers
- runtime/softtimer: use consistently the same clock source
- runtime/softtimer: fix ticks range when computing ticks diff
- tinyusb: allow max USB descriptor string to be configured
- runtime/pyexec: don't allow Ctrl+C to interrupt frozen boot code
- tinyusb: revert setting of CFG_TUD_CDC_EP_BUFSIZE to 256

drivers:
- hts221: add HTS221 humidity sensor driver
- lsm9ds1: add LSM9DS1 IMU driver
- lps22h: add LPS22HB/HH pressure sensor driver
- lps22h: use machine.idle for power saving
- ninaw10/nina_wifi_bsp: use MP_REGISTER_ROOT_POINTER()
- fix a few typos in comments
- cyw43: allow configuring the netif/mDNS hostname
- sdcard: add delay in init_card_v1 to make timeout work
- wiznet5k: remove old Wiznet driver
- cc3000: remove CC3000 WiFi driver files
- display: don't include tests by default
- remove drivers that are now in micropython-lib
- ninaw10: connect to WiFi asynchronously
- bus: detect QSPI transfer errors and pass up to spiflash driver
- bus: change QSPI read_cmd signature to return an error code
- ninaw10: implement machine.Pin external pin controls
- cyw43: use board-defined BLE UART secondary baudrate
- cyw43: use a different baudrate for BT firmware download
- ninaw10: fix machine_pin GPIO read
- cyw43: include CYW43 config file
- ninaw10: add missing external pins 34 and 39
- ninaw10: fix ESP32 input-only pins

mpy-cross:
- Makefile: respect existing CFLAGS and LDFLAGS
- remove .gitignore file
- include alloca.h for NetBSD
- mpy_cross: add Python wrapper for mpy-cross
- mpy_cross: fix default path to mpy-cross binary
- mpy_cross: add a way to query the mpy version
- mpy_cross: add list of architectures to `__all__`
- mpy_cross: add docstrings to public methods
- main: don't set a default native architecture
- main: add MSVC-compatible architecture checks
- force forward slashes in paths
- main: fix return type of mp_import_stat

lib:
- cyw43-driver: add new submodule for CYW43xx WiFi driver
- pico-sdk: update to version 1.4.0
- cyw43-driver: update cyw43-driver to fix ap_auth mode setting
- tinyusb: update to the most recent master
- cyw43-driver: update driver to latest version
- micropython-lib: add micropython-lib as a submodule
- lwip: update lwIP to v2.1.3, tag STABLE-2_1_3_RELEASE
- micropython-lib: update to latest version with manifest changes
- micropython-lib: update submodule to latest
- stm32lib: update library to get L1 v1.10.3, and some other fixes
- micropython-lib: update submodule to latest
- btstack: update to v1.5.3
- micropython-lib: update submodule to latest
- libm: use __asm__ instead of asm
- btstack: update to v1.5.4
- cyw43-driver: update driver to latest version
- re1.5: reduce code size when checking for named class char
- re1.5: add support for named classes in class sets
- micropython-lib: update submodule to latest
- cyw43-driver: update driver to latest version
- pico-sdk: update to version 1.5.0
- cyw43-driver: update driver to latest version v0.9.0
- micropython-lib: update submodule to latest
- stm32lib: update library to get H7 v1.11.0
- cyw43-driver: update driver to latest version v1.0.0
- micropython-lib: update submodule to latest

Support components
==================

docs:
- update to use new WLAN argument names for ssid/security/key
- library/pyb.Timer: document `brk` argument and its constants
- library: remove unnecessary "pyb." prefix on class names
- set LaTeX engine to XeLaTeX for PDF generation
- library/machine: add note on interrupts being critical to system
- library/uasyncio: consistently use "uasyncio" instead of "asyncio"
- library/bluetooth: add link to aioble
- library/neopixel: add note that neopixel is included in rp2 builds
- library/time: provide more info about which epoch is used
- library/pyb.Pin: fix out-of-context paragraphs, and AF_PP typo
- library/pyb.Pin: add Pin.ALT constant
- library/pyb.Timer: document how to use BKIN pin with example
- update links for Arm GCC toolchain
- library/rp2: fix pull_thresh docs to use pull instead of push
- esp32: fix string quoting consistency in SDCard mount example
- update CPython differences and improve the look of table layouts
- esp32: update UART quickref on input-only pins
- library/machine.UART: add notes about UART init and deinit
- library: fix nested rst styles not rendering
- library/micropython: fix spelling of compiler
- templates/topindex.html: update forum link
- library/machine.I2C: add a note about I2C pull-up resistors
- library/machine.UART: add docs for uart.flush() and uart.txdone()
- renesas-ra: add pin drive keyword argument description
- Makefile: enable parallel compilation for Sphinx
- templates/layout.html: indicate latest vs release docs
- samd: add documentation for the samd port
- library/machine: add machine.memX to docs with brief example
- samd/pinout: fix the pin numbering for the default assignments
- develop: fix mp_compile snippet to match latest code
- renesas-ra: correct the internal file system size of EK-RA6M2
- library/array: add docs for dunder methods
- library/pyb.CAN: update the recv example to take a 5-tuple
- library/uasyncio: describe restriction on ThreadSafeFlag
- library/framebuf: clarify docs for blit regarding palette
- library/struct: fix buffer argument description
- library/struct: embed format tables
- library/neopixel: update GitHub URL for neopixel.py link
- differences: update Python 3.9 status
- differences: add Python 3.10 page
- rp2: make LED have exactly 50% duty cycle in PIO 1Hz example
- library/rp2.StateMachine: expand put() documentation
- library/socket: use correct sockaddr variable name
- esp32/quickref: add docs for the LAN interface constructor
- library/machine.Timer: add freq argument to machine.Timer
- reference/constrained: add missing heap-dump symbols to mem_info()
- zephyr/quickref: fix zsensor module usage examples
- library/network: update docs for network.country, network.hostname
- update copyright year range to include 2023

examples:
- embedding: remove obsolete axtls build target
- usercmodule: add example of a native C class
- embedding: rework example to use ports/embed
- rp2: add comment that examples using IO25 don't work on Pico W
- bluetooth: fix check for _conn_handle being None
- usercmodule/cexample: use mp_obj_malloc()
- bluetooth/ble_temperature_central.py: remove service tuple

tests:
- extmod: add heap-lock test for stream writing
- basics: add tests for __name__ and __globals__ attrs on closures
- perf_bench: add some configurations for N=32, M=10
- add an explanation of run-perfbench.py
- fix run-perfbench parsing "no matching params" case
- micropython: add test for builtin execfile() function
- extmod/ussl_basic: make test run on axtls and mbedtls
- cpydiff: fix formatting of code snippet to use double quotes
- run-tests.py: provide better default MPYCROSS value for Windows
- extmod/ubinascii: add tests for bytes.hex etc
- update path to unix micropython executable
- unicode: add test for invalid utf-8 file contents
- renesas-ra: update pin test to support all boards
- extmod/uasyncio_heaplock.py: force SKIP on stackless
- frozen: move frozentest.mpy from ports/ to tests/
- run-multitests: extend usage information
- run-multitests: make paths more deterministic
- allow 'special' tests to output "SKIP" on a single line
- extmod: add test for sleep_ms value that overflows ticks
- run-perfbench: support --heapsize argument and pass to executable
- basics: add exp file for builtin_str_hex test
- run-tests.py: use host arch for mpy-cross for target=unix
- misc: add test for cexample module
- misc/cexample_module: test class presence
- misc/cexample_class: fix timing sensitivity
- extmod/framebuf_scroll: add tests for FrameBuffer scrolling
- unix/mod_os: add test for os module
- extmod/ure_namedclass: add tests for named classes in class sets
- float: skip new complex tests if complex unavailable
- extmod: get DecompIO test running on low-memory targets
- extmod: skip vfs tests if target doesn't have enough memory
- micropython: split viper_misc test into two files
- float: add domain checks for log and also -inf
- float: make output of math function tests more readable
- run-multitests.py: add ability to test instance over reboot
- multi_bluetooth: add bluetooth multi-test for deepsleep
- run-multitests.py: support outputting test metrics
- multi_bluetooth: use multitest.output_metric in BLE perf tests
- extmod/vfs_fat_ilistdir_del.py: use 512-byte erase block size
- multi_bluetooth: use time.sleep_ms instead of time.sleep
- multi_bluetooth/ble_mtu: split peripheral/central-initiated
- multi_bluetooth/ble_subscribe: use end_handle in desc discovery
- multi_bluetooth: add test for descriptors
- multi_bluetooth/ble_characteristic.py: add write-no-response
- multi_bluetooth: use multitest.broadcast instead of sleep

tools:
- metrics.py: add mimxrt and renesas-ra to list of available ports
- ci.sh: drop ppa requirement for code formatting CI
- pyboard.py: add verbose option to filesystem_command
- mpremote: don't be verbose when using cat command
- autobuild: add nrf port to autobuild scripts
- ci.sh: initialise submodules for more ports
- ci.sh: force mpy-cross build for samd and teensy
- update path to unix micropython executable
- mpremote: allow + terminator for fs commands
- pyboard.py: add "touch" filesystem command
- mpremote: add "edit" command
- ci.sh: split the stm32 builds for wiznet5k and cc3k
- mpremote: print a nicer error when a filesystem command fails
- pyboard.py: remove implicit fs_put if source starts with ./
- pyboard.py: add fs_cp function for direct device-to-device copy
- mpremote: print nicer errors for unsupported 'cp -r' arguments
- manifestfile.py: add library for working with manifests
- makemanifest.py: update to use mpy_cross module
- manifestfile.py: allow include of directory path
- manifestfile.py: allow require() to specify unix packages
- manifestfile.py: allow manifests to set metadata
- autobuild: use distinct directory for building stm32 variants
- makemanifest.py: force the repo version of the mpy_cross package
- pyboard.py: support Windows pathname separators
- manifestfile.py: add `author` kwarg to metadata()
- manifestfile.py: replace recursive glob with os.walk
- mpremote: simplify dispatch of commands
- mpremote: use argparse for command line parsing
- mpremote: add `mpremote mip install` to install packages
- pyboard.py: handle unsupported fs command
- add note about uncrustify versions
- add pre-commit support
- mpremote: fix argument handling for follow and add help strings
- mpremote: bump version to 0.4.0
- verifygitlog.py: ignore comment lines in commit messages
- verifygitlog.py: add additional help for subject line issues
- mpremote: handle FileNotFound exceptions in listdir
- mpremote: make RemoteFile objects iterable
- makemanifest.py: fix printing of mpy_cross.CrossCompileError
- gen-cpydiff.py: use os.path.join and os.path.isdir
- gendoc.py: remove unused script
- ci.sh: add ARDUINO_NANO_RP2040_CONNECT to rp2 CI build
- ci.sh: remove one build from zephyr CI to speed it up
- ci.sh: don't print python2 version
- mpremote: allow EDITOR environment variable to work on Windows
- mpremote: only auto connect to serial device with USB VID/PID
- autobuild: create .uf2 file for seeed_xiao_nrf52
- pyboard.py: fix Python 2 compatibility
- pyboard.py: add parse kwarg to eval
- pyboard.py: add fs_{listdir,readfile,writefile,stat}
- pyboard.py: set DTR on Windows to avoid ESPxx hard reset
- mpy-tool.py: initialize line_info_top
- ci.sh: install pkg-config for macos builds
- ci.sh: add unix, stm32 and rp2 ports to code size check
- mpremote: use hatch to build mpremote package
- pyboard.py: use '/' exclusively when dealing with paths
- pyboard.py: fix joining of path in filesystem_command
- pyboard.py: fix ESPxx boards hanging in bootloader after reset
- manifestfile.py: add support for publishing packages to PyPI
- mpremote: add ctrl-x as additonal mpremote disconnect shortcut

CI:
- ISSUE_TEMPLATE: make minor improvements to placeholder text
- ISSUE_TEMPLATE: replace forum with Discussions
- workflows: print test failures for webassembly workflow
- workflows: bump actions/checkout to v3
- add dependabot to update GitHub Actions
- workflows: bump codecov/codecov-action from 1 to 3
- workflows: bump actions/setup-python from 1 or 2 to 4
- workflows: run unix port workflow if mpy-cross changes
- workflows: use ubuntu-20.04 when python2 is required
- workflows: run mpy-format CI when tests and examples change
- workflows: comment on code size change instead of failing CI
- workflows: fix code size comment workflow for non-PR
- workflows: cancel when branch is updated
- workflows: update existing comments for code_size_comment
- workflows/code_size: print code size change
- workflows: add "shared/**" to list of paths that trigger CI
- workflows: add workflow to build mpremote wheel
- workflows: bump actions/setup-python from 1 to 4
- workflows: bump actions/checkout from 2 to 3
- workflows: bump actions/upload-artifact from 2 to 3

The ports
=========

all ports:
- adapt mimxrt, nrf and rp2 ports to work with latest TinyUSB
- fix a few typos in comments
- remove unused mp_type_{fileio/textio} macros in mpconfigport.h
- always include debug information in the ELF
- always append to GIT_SUBMODULES
- use micropython-lib version of drivers in manifests
- make generated pin.c handling more consistent across ports
- make all network-capable boards use bundle-networking
- make BOARD default from BOARD_DIR in Makefile's
- rename remaining "Micro Python" to "MicroPython"
- fix MCU tags in Arduino board.json files
- implement simple write polling for stdout

bare-arm port: no changes specific to this component/port

cc3200 port:
- mpconfigport: remove mp_const_user_interrupt
- use MP_REGISTER_ROOT_POINTER()
- fix various array-based compiler warnings
- mods/pybuart: implement uart.flush() and uart.txdone()
- remove unused NIC type customisation

embed port:
- add new "embed" port which builds a simple C package
- fix arguments to mp_raw_code_load_mem

esp8266 port:
- modnetwork: rename WLAN keyword args to ssid/security/key
- mpconfigport: switch to ROM feature level configuration
- mpconfigport: disable MICROPY_PY_UTIMEQ
- rename WLAN dhcp_hostname config to hostname
- boards: enable reverse-special-methods on GENERIC board
- use MP_REGISTER_ROOT_POINTER()
- modnetwork: add support for WLAN.config(protocol=XX) option
- README: update build instructions to match ci.sh
- machine_uart: implement uart.flush() and uart.txdone()
- modmachine: move dht_readinto() to the machine module
- machine_pwm: enable real open drain output on pin driven by PWM
- machine_pin: disable open drain when pin becomes input/output
- modnetwork: add ability to set tx power for WLAN interface
- README: remove notice about port being "experimental"
- use extmod/modnetwork.c instead of port-specific version

esp32 port:
- network_wlan: rename WLAN keyword args to ssid/security/key
- machine_uart: implement the functionality of timeout_char arg
- boards: increase 512 bytes limit on ULP programs to 2040
- modesp32: add wake_on_ulp() so ULP can wake CPU from deepsleep
- network_wlan: don't raise exception when scan returns no results
- rename WLAN dhcp_hostname config to hostname
- modmachine: fix machine.freq to allow maximum 160MHz on ESP32-C3
- use MP_REGISTER_ROOT_POINTER()
- mpconfigport: enable BLE synchronous events and pairing/bonding
- Makefile: force micropython-lib as a required submodule
- network_wlan: use esp_wifi_set/get_channel to config wifi channel
- network_wlan: add support to set/get the wifi protocol
- modnetwork: add network.MODE_LR constant
- machine_uart: change sendbreak time to be at least 15 bit times
- machine_timer: support all init arguments in Timer constructor
- boards: merge manifest_release modules into standard manifest
- machine_sdcard: free SPI bus when deiniting SD card
- machine_uart: implement uart.flush() and uart.txdone()
- mphalport: fix calculation of large sleep by using 64-bit arith
- Makefile: add link to build troubleshooting on failure
- modsocket: use mp_obj_is_integer to test port type
- machine_pwm: don't use LEDC_USE_REF_TICK on ESP32-C3 variants
- machine_i2s: add I2S finaliser which calls deinit()
- machine_hw_spi: use auto DMA channel on S2, S3, C3 chips
- rename machine I2C and SPI types consistently across ports
- machine_i2c: fix clocks and timeouts for ESP32-C3, ESP32-S3
- machine_pin: fix size of machine_pin_irq_handler array
- machine_pwm: verify PWM is active when config methods are called
- add 32MiB partition table templates
- usb: add a timeout to usb_tx_strn()
- modmachine: move dht_readinto() to the machine module
- boards/GENERIC_S3_SPIRAM: enable BLE support
- boards/GENERIC_S3_SPIRAM: enable BLE
- machine_timer: fix ESP32C3 timer period doubling
- machine_touchpad: fix TouchPad for ESP32S2, ESP32S3
- main: don't call usocket_events_deinit if unavailable
- usb: cleanup connection detection
- boards/GENERIC_S3_SPIRAM_OCT: add ESP32S3 board with Octal SPIRAM
- network_lan: add support for LAN8710 PHY
- network_lan: support configuration of ETH ref_clk pin
- network_lan: add support for SPI-based ethernet chips
- network_lan: fix setting MAC address of ethernet devices
- network_lan: fix compilation on IDF lower than v4.4
- machine_sdcard: change dma_channel to SPI_DMA_CH_AUTO for ESP32S3
- boards: add board definition for Olimex ESP32 PoE boards
- boards/GENERIC_UNICORE: add board definition for unicore chips
- network_lan: add support for Ethernet PHY KSZ8081
- add a small delay before leaving wlan.active()
- boards/OLIMEX_ESP32_POE: remove id from and update board.json
- Makefile: allow specifying BOARD_DIR on make command line
- use extmod/modnetwork.c instead of port-specific version
- machine_pin: use const for size of machine_pin_irq_handler array
- esp32_rmt: fix looping behaviour for RMT on ESP32-S3

mimxrt port:
- Makefile: refactor Makefile and divide it into sections
- Makefile: modify handling of SDRAM option
- Makefile: modify handling of SDCARD option
- Makefile: rework board flash type handling
- Makefile: rework floating point config
- Makefile: fix some minor formatting inconsistencies
- boards: remove conditional assignment of flash type/size
- use MP_REGISTER_ROOT_POINTER()
- machine_uart: implement uart.flush() and uart.txdone()
- machine_uart: drop a few commented lines about TX ring buffer
- format the firmware image to match the new teensy loader
- machine_spi: allow a setting of -1 for cs in the constructor
- machine_uart: set the UART ioctl write poll flag properly
- machine_uart: fix a bug in UART.write()
- Makefile: split up SRC_C variables
- machine_pin: add the Pin.toggle() method
- fix CPU freeze when calling __WFE() in MICROPY_EVENT_POLL_HOOK
- machine_timer: use soft-timer implementation for machine.Timer
- machine_timer: use extmod version of machine.Timer
- mphalport: add a timeout to mp_hal_stdout_tx_strn()
- modmachine: move dht_readinto() to the machine module
- add support for MIMXRT1176 MCUs, and MIMXRT1170_EVK board
- README: add build and flashing instructions
- usb: change macro name MICROPY_HW_USB_STR_MANUF
- network: rename the argument clock_mode to ref_clk_mode
- Makefile: set MPY_CROSS_FLAGS
- mpconfigport: remove config options that are set by default
- machine_rtc: set the microsecond value to 0
- sdcard: fix an error when writing large blocks
- sdcard: remove obsolete code already excluded by preprocessor
- set MICROPY_GC_STACK_ENTRY_TYPE to uint32_t for large RAM
- Makefile: move the FROZEN_MANIFEST setting after board config
- enable ROM text compression
- pendsv: add MICROPY_BOARD_PENDSV_ENTRIES for board customisation
- pendsv: clean up PendSV code
- Makefile: fix internal flash configuration and build
- boards/MIMXRT1064_EVK: fix board config to use internal flash
- mpconfigport: allow configuring different network interfaces
- modmachine: implement machine.bootloader()
- fix the build for boards without ROM API

minimal port:
- Makefile: avoid terminal reset, use BUILD variable
- Makefile: set linker to $(CC)
- increase heap size for Linux builds

nrf port:
- main: add startup and early-init board hook macros
- modmachine: add machine.bootloader() and make it customisable
- enable optional support for Arduino 1200bps touch
- Makefile: drop unused MPY_CROSS and MPY_TOOL variables
- boards/arduino_nano_33_ble: add Arduino Nano 33 BLE sense board
- modmachine: add machine.idle() function
- mpconfigport: remove obsolete module declarations
- drivers/bluetooth: handle PHY_UPDATE messages, used in Bluetooth 5
- drivers/usb: probe for interrupt char in USB CDC task
- drivers/usb: add a tud_cdc_rx_cb() callback to check interrupt char
- mpconfigport: call tud_task() in MICROPY_EVENT_POLL_HOOK
- drivers/usb: fix reading of a single USB CDC character
- use MP_REGISTER_ROOT_POINTER()
- boards/arduino_nano_33_ble_sense: update deploy instructions
- main: call usb_cdc_init() before executing boot.py and main.py
- modules/ubluepy: use mp_obj_str_get_data to extract str data
- don't enable debug info by default if LTO is on
- modules/machine/uart: implement uart.flush() and uart.txdone()
- Makefile: split up SRC_C variables
- rename machine I2C, PWM, SPI, UART types consistently across ports
- rename MICROPY_PY_MACHINE_TIMER to MICROPY_PY_MACHINE_TIMER_NRF
- boards/seeed_xiao_nrf52: add defn for Seeed XIAO NRF52840 Sense
- mpconfigport: enable seeding of the PRNG by the hardware RNG
- Makefile: add support for BOSSAC flasher
- boards/arduino_nano_33_ble_sense: add support for REV-2 chipset
- modules/machine/pwm: add paramter checks and error messages
- modules/machine/pwm: use extmod/machine_pwm.c for PWM module
- modules/machine/soft_pwm: add PWM for nrf51x boards using soft PWM
- modules/machine/pwm: support using all 4 channels of a PWM module
- modules/machine/uart: add timeout keyword options and "any" method
- nrfx_config: use the UARTE definitions and drivers for the NRF52xx
- modules/machine: use a dedicated function for machine.idle()
- modules/machine: support the freq=n argument for machine.I2C
- modules/machine/pwm: fix resource conflict, and change id to device
- nrfx_config: use UARTE for nrf52xxx devices
- modules/machine/uart: prevent UART lock-up after a receive error

pic16bit port:
- pic16bit_mphal: use MP_REGISTER_ROOT_POINTER()

powerpc port: no changes specific to this component/port

qemu-arm port: no changes specific to this component/port

renesas-ra port:
- modmachine: allow boards to provide custom bootloader code
- machine_i2c: remove unnecessary start/stop dummy functions
- mpconfigport: drop pyb_hid_report_desc root pointer
- use MP_REGISTER_ROOT_POINTER()
- softtimer: switch to use softtimer code from shared/runtime
- machine_pin: support drive keyword and fix GPIO setting
- rename machine SPI type consistently across ports
- machine_timer: use extmod version of machine.Timer
- boards: update linker script to detect code flash overflow
- disable debugging option for RA4 to reduce code size
- change file system size to 64KB for RA6M1
- add the UART methods uart.txdone() and uart.flush()

rp2 port:
- modmachine: allow boards to provide custom bootloader code
- boards/ARDUINO_NANO_RP2040_CONNECT: enable Arduino 1200bps touch
- modmachine: implement lightsleep() with optional sleep period
- mpthreadport: ensure core1 doesn't hold gc lock in deinit
- mbedtls: enable some more mbedtls options
- lwip_inc: enable lwIP status callback
- rp2_flash: add asserts for size of flash filesystem partition
- mpnetworkport: convert network task scheduling to use PendSV IRQ
- integrate CYW43xx WiFi driver
- boards/PICO_W: add new Pico W board, an RP2040 with WiFi
- boards/GARATRONIC_PYBSTICK26_RP2040: change pico-sdk board name
- main: set default AP auth mode to WPA2_AES_PSK
- mpconfigport: factor core event handling to EVENT_POLL_HOOK_FAST
- Makefile: regenerate cmake if generated Makefile missing
- CMakeLists: give error if required submodules are missing
- CMakeLists: don't override cyw43-driver unless necessary
- boards/ARDUINO_NANO_RP2040_CONNECT: add urequests module
- run USB stack task exclusively from core 0
- make atomic sections suspend the other core (if active)
- mpconfigport: make networking options consistent across boards
- mphalport: fix missing storage_read_blocks symbol in debug build
- CMakeLists: use armv6m mpy-cross arch for rp2
- use MP_REGISTER_ROOT_POINTER()
- mpbthciport: remove mp_bthci_uart from set of root pointers
- cyw43_configport: set CYW43_EVENT_POLL_HOOK value
- cyw43_configport: set CYW43_WIFI_NVRAM_INCLUDE_FILE value
- rp2_pio: fix StateMachine.restart when PIO program is shared
- cyw43_configport: add event hook into cyw43_delay_ms
- Makefile: always use cmake to discover submodules
- mbedtls: enable certificate validity time validation
- machine_spi: add mp_hal_get_spi_obj helper function
- boards/W5500_EVB_PICO: add new board definition for W5500_EVB_PICO
- mark gc_heap NOLOAD for faster boot
- correctly determine path to arm-none-eabi-size
- machine_wdt: check for the maximum timeout value of watchdog
- machine_uart: implement uart.flush() and uart.txdone()
- mbedtls: fix missing time.h include
- rp2_flash: add start/len support to rp2.Flash() constructor
- boards: set PICO_BOARD correctly for each board
- machine_spi: use pico-sdk's default pins for SPI
- machine_i2c: use pico-sdk's default pins for I2C
- boards: remove all I2C,SPI pin defs that already match pico-sdk
- Makefile: add link to build troubleshooting on failure
- Makefile: add support for BOARD_VARIANTS
- boards/WEACTSTUDIO: add WEACTSTUDIO with multiple variants
- fatfs_port: fix the modification date of files
- rename machine I2C type consistently across ports
- mphalport: add a timeout to mp_hal_stdout_tx_strn()
- cyw43_configport: make sure only core0 executes a __WFI()
- modmachine: move dht_readinto() to the machine module
- allow enabling USB device without enabling USB-CDC
- boards/ARDUINO_NANO_RP2040: add more modules and enable MD5 hash
- fix lightsleep to work with interrupts and cyw43 driver
- machine_pwm: use more accurate formulas for freq and duty_u16
- machine_pwm: fix overflows with freq > 268 MHz
- mphalport: change order of pin operations to prevent glitches
- rp2_flash: call MICROPY_EVENT_POLL_HOOK_FAST after reading flash
- machine_pin: refactor the machine.Pin class for external GPIO
- machine_pin: add support for named pins and alternate functions
- boards: add pin CSV files to board definitions
- fix crash in a pin.irq handler
- main: use mp_printf in nlr_jump_fail
- machine_pin: fix configuring OPEN_DRAIN with initial value
- boards/NULLBITS_BIT_C_PRO: add Bit-C PRO board
- rp2_pio: track use of PIO resources and free them on soft reset
- boards/ARDUINO_NANO_RP2040_CONNECT: use default aioble
- mpconfigport: enable os.dupterm and hashlib.sha1 on all boards
- cyw43_configport: specify the chipset firmware include file
- Makefile: allow specifying BOARD_DIR on make command line
- pendsv: add MICROPY_BOARD_PENDSV_ENTRIES for board customisation
- boards/ARDUINO_NANO_RP2040_CONNECT: include "time" in manifest
- boards/ARDUINO_NANO_RP2040_CONNECT: add more external pins
- boards/ARDUINO_NANO_RP2040_CONNECT: include "senml" in manifest
- modrp2: support reading the BOOTSEL button on the Pico board
- modrp2: disable other core, shorten delay to 8us in bootsel_button
- allocate GC heap from unused RAM
- allow disabling USB via MICROPY_HW_ENABLE_USBDEV config
- main: keep UART REPL with DEBUG=1 and MICROPY_HW_ENABLE_UART_REPL=1
- machine_uart: fix setting of UART LCR parameters
- machine_i2c: add timeout parameter for machine.I2C()
- memmap_mp.ld: allow a board to reserve memory for the C heap

samd port:
- mpconfigport: enable MICROPY_ENABLE_FINALISER when VFS is used
- remove the existing provisional support for REPL on UART
- boards: replace pins.c and pins.h by pins.csv
- boards: move mcu-specific settings into a mpconfig_samdXX.h file
- Makefile: alphabetically sort the source code files in Makefile
- boards: add ADAFRUIT_FEATHER_M4_EXPRESS and _ITSYBITSY_M0_EXPRESS
- clock_config: set up the clock configuration
- modmachine: allow changing the CPU freq with machine.freq(f)
- mphalport: add pin open-drain funcs, and improve delay and ticks
- samd_isr: extend systick_ms to 64 bit
- machine_pin: add OPEN_DRAIN mode for pins
- machine_pin: allow specifying a pin or LED by its name as a string
- modmachine: enable SoftSPI and SoftI2C
- boards: create pin_af_table.c from pin_af_table_SAMDxx.csv files
- pin_af: add the pin af table and its helper functions
- machine_adc: add the machine.ADC class
- machine_pwm: add the machine.PWM class
- samd_isr: rework the interrupt tables
- machine_pin: add pin.irq() to the machine.Pin class
- modmachine: add disable_irq(), enable_irq() and idle() to machine
- machine_uart: add the machine.UART class
- machine_spi: add the machine.SPI class
- machine_i2c: add the machine.I2C class
- moduos: add uos.dupterm()
- moduos: add uos.urandom() for SAMD51
- main: use the common execution mode of boot.py and main.py
- mpconfigport: enable a few more MicroPython features
- samd_isr: change the way a Sercom ISR is registered and called
- machine_timer: add machine.Timer based on the shared soft-timer
- machine_wdt: add the machine.WDT class
- modsamd: add pininfo() function to the samd module
- machine_led: optimise size of the machine.LED class
- machine_dac: add the machine.DAC class
- modmachine: add machine.time_pulse_us
- mcu: factor out MCU policy for SAMD21 and SAMD51
- mphalport: add a mp_hal_ticks_ms_64() function
- modutime: enable time.time() based on systick_ms()
- machine_uart: support buffered TX for UART
- boards: add missing/lost board config and pin definitions
- mphalport: use CYCCNT for SAMD51's mp_hal_ticks_cpu()
- machine_bitstream: add the machine.bitstream() function
- mpconfigport: restructure to use ROM feature levels
- clock_config: split clock_config.c to separate SAMD21/SAMD51 files
- clock_config: add HW_DFLL_USB_SYNC and HW_MCU_OSC32KULP extensions
- pin_af: simplify the pin-af-table handling
- samd_flash: remove obsolete printf's and return values instead
- Makefile: fix a dependency problem with "make -j"
- mphalport: fix USB endpoint handling ignoring Ctrl-C
- change the symbol names for the peripheral clocks
- mcu: add floating point suport for SAMD21 devices
- mcu: enable the math module on SAMD51
- boards: move the flash filesystem definitions to the linker files
- boards: use the same linker file for all SAMD51x19 variants
- main: initialize readline on start up
- mcu: use lf2s for SAMD51 and lfs1 for SAMD21
- machine_pin: change the printing of Pin and LED objects
- Makefile: split up SRC_C variables
- rename machine I2C type consistently across ports
- clock_config: extend the range of machine.freq()
- clock_config: support changing machine.freq() for SAMD21
- modmachine: add machine.reset_cause()
- boards/SPARKFUN_SAMD51_THING_PLUS: add board files for Thing Plus
- modmachine: add machine.dht_readinto and enable on SAMD51
- mcu/samd51: enable onewire support for SAMD51
- mcu/samd51: enable FAT support for SAMD51
- modmachine: implement machine.lightsleep()
- modmachine: get the bootloader magic address from the lib
- clock_config: document the #defines use in init_clocks()
- machine_uart: implement uart.txdone() and uart.flush()
- mcu: make some settings in mpconfigmcu.h conditional
- machine_rtc: add the machine.RTC class
- clock_config: extend the SAMD51 us-counter to 60 bit
- boards/SEEED_WIO_TERMINAL: declare more pins for SEEED WIO board
- machine_pin: change the pin handling and naming/numbering
- make ADC, DAC, PWM, SPI objects consistent in how they print out
- modmachine: replace the LED class by the Signal class
- boards: rework the pins.csv files
- machine_pwm: serialize fast update of PWM settings
- machine_uart: use a finaliser to tidy up UART on soft reset
- machine_spi: implement spi.deinit() and simplify sercom_deinit_all
- machine_spi: register SerCom objects as root pointers
- modmachine: add machine.softreset()
- machine_timer: use extmod version of machine.Timer
- mcu/samd51: use an additional manifest.py for SAMD51 boards
- README: update README to reflect recent changes to the port
- boards/SEEED_WIO_TERMINAL: enable using the 32kHz crystal
- mphalport: add a timeout to mp_hal_stdout_tx_strn()
- move MCU-specific CFLAGS to mpconfigmcu.mk
- Makefile: set MPY_CROSS_FLAGS
- mpconfigport: support MICROPY_HW_SOFTSPI_MIN_DELAY
- mpconfigport: use __WFE() in MICROPY_EVENT_POLL_HOOK
- avoid under-/overflow in I2C and SPI baudrate calculations
- machine_uart: fix IRQ flag setting and clearing
- machine_uart: simplify machine_uart_any() and machine_uart_read()
- machine_uart: check the UART TX pin assignment
- machine_uart: fix uart.deinit() and save some RAM
- add a vref=num option to the ADC and DAC constructor
- support entering bootloader via USB CDC 1200bps touch
- boards/SEEED_XIAO: rename to SEEED_XIAO_SAMD21
- add Pin.board and Pin.cpu classes to Pin
- boards: clean up comments and some pins in pins.csv files
- mcu: rework the comments in clock_config.c
- mcu: use the FDPLL96M clock for the SAMD21 CPU
- mcu: implement a hardware seed for the SAMD21 random module
- mcu: set the SAMD21 us-counter to 2 MHz for better resolution
- moduos: add uos.urandom() using the phase-jitter rng
- pendsv: add MICROPY_BOARD_PENDSV_ENTRIES for board customisation
- always provide the machine.RTC class

stm32 port:
- modmachine: allow boards to provide custom bootloader code
- modmachine: factor out mboot enter code to a function
- boards/stm32f091xc.ld: allocate space for a small filesystem
- boards/NUCLEO_F091RC: enable LFS1 filesystem
- Makefile: set CSUPEROPT to -Os for F0 and G0 MCUs to save space
- usbd_cdc_interface: add support for Arduino 1200bps touch
- usb: expose USB HID device instance via usbd_hid_get()
- use a separate symbol name for the bootloader state pointer
- Makefile: enable link-time-optimisation via LTO=1 make option
- boards: enable LTO by default on boards with smaller flash size
- Makefile: fix setting of define that enables WIZNET5K driver
- mboot: remove redundant code in mboot_state_change function
- boardctrl: allow boards to override fatal-error handler
- sdram: include boardctrl.h for fatal-error handler
- use MP_REGISTER_ROOT_POINTER()
- Makefile: workaround LTO linker order bug in binutils <2.35
- softtimer: switch to use softtimer code from shared/runtime
- boards/LEGO_HUB_NO6: fix typo in README
- boards/LEGO_HUB_NO6: use named pins
- boards/LEGO_HUB_NO6/appupdate: detect filesystem size at runtime
- boards/LEGO_HUB_NO6/spiflash: pick command type at runtime
- boards/LEGO_HUB_NO6/cc2564: make timer configurable
- boards/LEGO_HUB_NO7: add LEGO Hub No. 7 board definition
- boards/NUCLEO_WB55: add error handling to firmware update scripts
- don't enable debug info by default if LTO is on
- switch Wiznet to use lib/wiznet5k and extmod/network_wiznet5k
- add definitions required for lwIP version of Wiznet NIC
- mphalport: add mp_hal_get_spi_obj() helper function
- sdram: enable MPU for unaligned access on H7 MCUs
- boards: increase mboot region to 32k for WB55 boards
- move board variant config to mpconfigboard.mk
- boardctrl: use HAL_Delay instead of mp_hal_delay_ms
- remove support for CC3000 WiFi driver
- machine_uart: implement uart.flush() and uart.txdone()
- boards/LEGO_HUB_NO6: update manifest to new format
- boards: only freeze LCD160CR driver in PYB board firmware
- adc: make ADCAll.read_channel reject invalid channels
- pyb_i2c: fix pyb.I2C to work with dma=True on F4 MCUs
- timer: fix use of timer channel callback() method on L4 MCUs
- boards: add alternate function list for STM32F446RE
- boards/PYB: fix handling of BOARD_VARIANT selection
- make-stmconst.py: support TypeDef's with a single char prefix
- add support for STM32L1 MCUs
- boards/NUCLEO_L152RE: add NUCLEO-L152RE board support
- rename machine I2C and SPI types consistently across ports
- boards/ARDUINO_PORTENTA_H7: revert to single-precision float
- mbedtls: enable mbedtls certificate time validation
- Makefile: allow overriding the default MBEDTLS_CONFIG_FILE
- boards/ARDUINO_PORTENTA_H7: add custom mbedtls config
- modmachine: move dht_readinto() to the machine module
- spi: downgrade SPIHandle definitions to static
- boards/ARDUINO_PORTENTA_H7: add more modules, I2C1 and SE pin
- usbd_desc: support USB strings on CDC interface descriptors
- Makefile: set MPY_CROSS_FLAGS based on MCU type
- pyb_i2c: fix failing pyb.I2C(dma=True) after receiving 1 byte
- i2c: fix I2C frequency calc so it doesn't exceed requested rate
- adc: fix reading internal ADC channels on L4 MCUs
- adc: fix ADCAll.read_core_temp() on L4 MCUs
- i2c: add hardware I2C implementation for STM32L1
- i2c: add hardware I2C implementation for STM32L4
- mboot: make all mboot sectors erase/write protected
- boards: add missing LPUART macros for H7 HAL
- boards/NUCLEO_F429ZI: enable I2C1 and I2C2 with default pins
- powerctrl: improve standby mode entry code for H7 MCUs
- boards/NUCLEO_F756ZG: add board definition for NUCLEO-F756ZG
- powerctrl: fix build on STM32G0xx and STM32H7Bx MCUs
- boards: consolidate linker snippets to reduce duplication
- Makefile: leave DFU mode after download when using dfu-util
- boards/NUCLEO_H743ZI2: refer to NUCLEO_H743ZI for frozen manifest
- boards/STM32F769DISC: fix building with USE_QSPI_XIP=1
- boards/ARDUINO_PORTENTA_H7: fix macro value check for QSPI
- boards/ARDUINO_PORTENTA_H7: use default aioble
- Makefile: clean up nested if-else to chained if-else-if
- update to use the open-source lib version of cyw43-driver
- boards: update linker scripts now that big_const is gone
- add a default implementation of pyb.country
- cyw43_configport: fix build for boards without an RF switch
- boards/PYBD_SF2: set CYW43 Bluetooth fimrware download baudrate
- cyw43_configport: allow boards to override default resource files
- boards/ARDUINO_PORTENTA_H7: update board config files
- Makefile: include HAL HSEM driver on H747 MCUs
- boards/ARDUINO_NICLA_VISION: add support for Arduino Nicla Vision
- boards/ARDUINO_GIGA: add support for Arduino Giga H7 board
- cyw43_configport: add cyw43_sdio_enable_high_speed_4bit function
- powerctrl: add sleep RCC semaphore management for WB55 MCUs
- powerctrl: disable WB55 BLE before entering deepsleep
- powerctrlboot: provide custom SystemInit for WB55
- powerctrl: don't compile WB helpers on WL MCUs
- boards: include "senml" in manifest for ARDUINO boards
- remove commented-out printf's and debugging code
- main: use mp_printf instead of printf for MPY start-up messages
- i2c: return error code and raise exception if I2C init fails
- spi: return error code and raise exception if SPI init fails
- modmachine: make machine.info print using mp_printf
- extint: make ExtInt.regs print using mp_printf
- pin: make pin_find debug output use mp_printf
- pybthread: make pyb_thread_dump take a printer as its argument
- boards/NUCLEO_H743ZI2: fix MCU tag in board.json file
- mphalport: update HAL version to 1.11.0 to match stm32lib
- add support for STM32H723 MCUs
- boards: add ld and af.csv for H723
- boards/NUCLEO_H723ZG: add new H723 board
- add support for USB on G0 MCUs
- mboot: add support for G0 MCUs
- boards/NUCLEO_G0B1RE: add config for USB and mboot
- boards/ARDUINO_NICLA_VISION: fix incorrect bootloader PID
- flash: fix get_bank function for STM32H750
- cyw43_configport: provide cyw43_hal_pin_config_irq_falling func

teensy port:
- mpconfigport: drop unused root pointers
- teensy_hal: use MP_REGISTER_ROOT_POINTER()

unix port:
- variants: move setting of MICROPY_PY_USELECT to port config file
- variants: enable remaining options on dev,coverage from ROM extra
- variants/coverage: change config to use ROM level everything
- variants/dev: allow all config options to be overridden
- moduos: include errno.h
- main: restore tty settings on nlr_jump_fail()
- alloc: use MP_REGISTER_ROOT_POINTER() for mmap_region_head
- mpconfigport: make MICROPY_EVENT_POLL_HOOK call usleep directly
- mbedtls: add custom config for mbedtls
- mpconfigport: switch ussl from axtls to mbedtls
- Makefile: only include axtls in GIT_SUBMODULES list when enabled
- Makefile: only checkout libffi submodule when used
- mpconfigport: allow overriding MICROPY_EVENT_POLL_HOOK
- enable MICROPY_GC_SPLIT_HEAP on coverage build
- unix_mphal: allow overriding hal time functions
- variants: remove variant suffix from executable filename
- modjni: add missing const qualifier
- remove .gitignore file
- modusocket: support proto and flags arguments to getaddrinfo
- include alloca.h for NetBSD
- mpconfigport: enable MICROPY_ENABLE_FINALISER when VFS is used
- variants: remove freedos and fast variants
- refactor mpconfigport.h and mpconfigvariant.h
- refactor mpconfigvariant.mk
- variants/coverage: add test for manifest freeze_mpy()
- enable sys.executable
- Makefile: don't use _MOD variable names
- modffi: move header includes inside MICROPY_PY_FFI guard
- variants: change mip package to mip-cmdline
- coverage: add extra GC coverage test for ATB gap byte
- moduos: implement 2-arg version of os.getenv()
- Makefile: disable building the shared library of libffi
- main: free pathbuf when there's an error opening a file

webassembly port:
- Makefile: remove obsolete disable of array-bounds warning
- rename this port from 'javascript' to 'webassembly'
- mpconfigport: use MICROPY_CONFIG_ROM_LEVEL_EXTRA_FEATURES
- add support for VFS and enable VFS_POSIX
- use Date's now() instead of getTime()
- change "stack" argument to "heapsize"
- support piping in a program on stdin
- dispatch micropython-print via document not mp_js_stdout
- README: update README to describe new stdout behaviour
- Makefile: change compiler optimisation from O3 to Os
- library: make use of CustomEvent detail property
- library: extract and send data to print as UInt8Array

windows port:
- provide a definition for MP_ALWAYSINLINE
- msvc: support compressed ROM text for error messages
- Makefile: update test dependency on $(PROG)
- make project file read-only for IDE
- .gitignore: simplify by removing build artefacts
- msvc: remove variant suffix from executable filename
- msvc: make mpy-cross independent of micropython variant
- msvc: fix qstr generation dependency
- msvc: fix module freezing

zephyr port:
- update include paths to use the zephyr namespace
- upgrade to Zephyr v3.1.0
- use MP_REGISTER_ROOT_POINTER()
- machine_uart: use mp_obj_str_get_str to get device name
- boards: add config for bbc_microbit_v2
- mpconfigport: enable MICROPY_ENABLE_FINALISER when VFS is used
- rename machine I2C and SPI types consistently across ports

Bug fix for esp32 SoftI2C

This is a bug fix release.  The changes are:

- extmod/machine_i2c: only use WRITE1 option if transfer supports it

  This fixes the machine.SoftI2C.readfrom_mem() method on esp32, so it
  writes the address to read from.

New mpy 6 file format with improved bytecode, addition of renesas-ra port

In this release of MicroPython the .mpy file format has been significantly
reworked and bumped to version 6.  The new format now contains data and
bytecode organised to be mostly static and ready to run in-place.  To
achieve this, qstr references from bytecode (and native machine code) now
go through a lookup table, to convert from local qstr number in the module
to global qstr number in the runtime that the module executes within.  This
means bytecode (and most native code) does not need rewriting when it is
imported.  Along with this change, the jump opcodes have been optimised to
emit 1-byte jump offsets when possible, which gives a good reduction in
bytecode size, saving RAM and reducing the size of .mpy files.

The change to the bytecode means that code constants (like long strings,
bytes objects and floats) are now shared and de-duplicated across the whole
module, rather than each code object having a separate constant table.  The
parser can also now turn a tuple of constants into a constant object, so
the tuple doesn't need to be built at runtime each time it is used.
Furthermore, any constant object can now be used in "X = const(obj)"
statements.

With these bytecode changes, .mpy files see around a 10% reduction in size
and frozen .mpy code sees about a 5% size reduction.  Heap memory use after
import is also down by around 5% (more savings are seen if the code uses
lots of constants).  Due to the qstr indirection performance of the VM is
slightly reduced on some benchmarks by a few percent, but the benefits of
smaller code and reduced RAM usage are deemed to outweigh this.  See commit
f2040bfc7ee033e48acef9f289790f3b4e6b74e5 for more details.

In the runtime, support has been added for multiple *args and **args in a
function call, following PEP 448.  Built-in modules can now have (optional)
mutable attributes, and this is used to implement sys.ps1/sys.ps2 which
allow the user to customise the REPL prompt.  This can be useful, for
example, to configure a different REPL for different boards so they can be
easily distinguished.  The sys module has also had the MicroPython git
version and build date appended to sys.version, sys.implementation._machine
has been added, and sys.implementation.mpy renamed to
sys.implementation._mpy.  The sys module can now be used to fully identify
the MicroPython version and target it is running on (and the platform
module provides additional information when it's available).

The MP_REGISTER_MODULE macro is now used to register all built-in C modules
and the third argument to this macro has been removed.  Any user-C-modules
will need to be updated.  Also support for MICROPY_PORT_BUILTIN_MODULES is
removed because this is no longer needed, and should be replaced by usage
of MP_REGISTER_MODULE (see commit 0a92469c10542d57ef0ea6b6cf2ed0cae9491dbe
for example).

The MP_REGISTER_MODULE macro is now used to register all built-in C modules
and the third argument to this macro has been removed.  Also support for
MICROPY_PORT_BUILTIN_MODULES is removed because this is no longer needed.

mpy-cross now supports the -march=armv6m option, which can be used with the
rp2 port.  The -mno-unicode has been removed.

The littlefs2 library has been updated to v2.5.0 which includes some
performance improvements and minor fixes.

At the REPL, a tab will now insert an indent when it follows whitespace,
and auto-indent is automatically disabled if a space or tab follows an
auto-indent.  This means that Python code can be pasted into the standard
REPL without messing up the indentation.

mpremote is now at version 0.3.0, with a progress indicator shown when
copying large files, and recursive copy fixed on Windows.  It also has the
following commands added: --help, --version, version, resume, soft-reset,
umount.

The esp32 port has a new machine.ADCBlock class and updated ADC class.
Fixes have been made to ADC2 channel mapping, low PWM frequencies,
UART initialisation of unspecified parameters, and RMT channel on S2/S3/C3
variants.  The Pin.PULL_HOLD constant has been replaced by a "hold" keyword
argument to the Pic constructor, and it's now possible to configure pin
drive strength.  I2C write-then-read transfers have been optimised to be
faster.  WLAN.config() now supports setting/getting the txpower.  New
boards include LOLIN C3 MINI ESP32-C3, LilyGO LoRa32, and UM ESP32-S3 based
boards.

The mimxrt port has updated the nxp_driver to v2.10 and fixed USB CDC RX
handling to not block.  Pin drive constants have been renamed to DRIVE_x to
match other ports, and the machine.I2S class has been added.  New boards
include Olimex RT1010 and MIMXRT1015_EVK.

The nrf port now includes uasyncio in the default board manifest, and
additional features have been enabled on nrf52840 and nrf9160 boards to
match the features on stm32, rp2 and esp32.  This includes enabling the
json, re, zlib and framebuf modules.

There is a new renesas-ra port which targets Renesas RA4M1, RA4W1, RA6M1
and RA6M2 MCUs, with board definitions for evaluation kits for these MCUs,
along with RA4M1 clicker.  This port currently supports Pin, ADC, SoftI2C,
I2C, SoftSPI, SPI, UART, Timer and RTC classes in the machine module, along
with the VFS and an internal flash filesystem.

The rp2 port now has optional USB MSC support, and optional dupterm
support.  The machine.UART class has init and deinit methods added, and
the ucryptolib module is now available.  The lwIP network stack has been
integrated, along with mbedtls for the ssl module, and these can be used
with the new Wiznet driver to provide Ethernet support.  The Wiznet
W5100S-EVB-Pico board has been added which makes use of this driver.  The
day-of-week value reported by time.localtime() has been fixed, memory
corruption when a thread is created on core1 has been fixed, and the UART
now uses a mutex when reading/writing to prevent character duplication in
code that uses both cores.

The stm32 port has added support for G0, G4 and WL MCUs.  The new boards
for these MCUs are NUCLEO_G0B1RE, NUCLEO_G474RE and NUCLEO_WL55.  The
ARDUINO_PORTENTA_H7 board has also been added, with full WiFi and BLE
support.  The rfcore on WB55 MCUs has been improved by removing an extra
layer of buffering, and the restriction on the use of address resolution
has been removed, meaning that the rfcore WS firmware should be updated
to v1.12.0 or later; see commit 26b1d31eda292d9cd5cfc68f14ce8055256fade8.
The board-level configuration of mboot has been significantly improved to
allow more control over system clocks, more hooks into the start up
process, and a hook for state change.  And the CRC32 of DFU files is now
verified before writing them.

The pyb.CAN class has been improved to support FD frames and buses with
mixed classic/extended-ID nodes, allowing extended IDs to be specified on a
per-message basis.  CAN.recv also now returns a value indicating if the
received message had an extended ID or not.  And CAN.initfilterbanks has
been removed, replaced with the num_filter_banks keyword argument to
CAN.init.  These are all breaking changes to the pyb.CAN class API and code
will need to be updated accordingly; see commit
5cdf9645711cc12b45e602ef5795c33895116fc4 for details.

The unix port now shows compiler information in the REPL banner to make it
consistent with how bare-metal ports work, and the "-X realtime"
command-line option has been added for macOS to get improved timing.  All
variants have switched to use the VFS subsystem, and use the VfsPosix class
for mounting the host's filesystem.  The os module has been consolidated
with all other ports and the minimal and standard variants gain the unlink,
chdir, getcwd and listdir functions.

The windows port has also switched to the VFS subsystem and VfsPosix.  It
adds support for micropython.schedule and uasyncio on the dev variant.  And
BCryptGenRandom has been used to implement os.urandom.

The zephyr port upgraded Zephyr to v3.0.0.

The change in code size since the previous release for various ports is
(absolute and percentage change in the text section):

       bare-arm:   +792  +1.394%
    minimal x86:  +2091  +1.286%
       unix x64: +10231  +1.995%
    unix nanbox:  +9777  +2.162%
          stm32:   +184  +0.047% PYBV10
         cc3200:   +904  +0.493%
        esp8266:  -1240  -0.177% GENERIC
          esp32:  +6464  +0.425% GENERIC
            nrf: +11288  +6.472% pca10040
            rp2: +14432  +2.929% PICO
           samd:  +1352  +0.970% ADAFRUIT_ITSYBITSY_M4_EXPRESS

The changes that dominate these numbers are:
- bare-arm, minimal, cc3200, samd: reworked bytecode and mpy format,
  optimisation of jump opcodes to use 1-byte offsets, de-duplication of
  constants at the module level, and PEP 448 support
- unix: switching to use VFS, and new mpy format and related changes
- esp8266: removal of esp.info and machine.WDT.deinit
- esp32: addition of machine.ADCBlock, and new mpy format changes
- nrf: enabling uasyncio, enabling MICROPY_PY_IO
- rp2: enabling ucryptolib with mbedtls

Note that the stm32 port's size remained roughly unchanged.  This is
because it has a decent amount of frozen Python code and the reduction in
frozen code size due to the reworked bytecode has offset the increase in
runtime/VM size due to this change.  Ports like bare-arm, minimal, cc3200
and samd do not have any frozen code so only see the increase in runtime/VM
size.  Production-level projects that have a significant amount of frozen
code have seen around a 4% overall reduction in their firmware size.

Thanks to everyone who contributed to this release: Algy Tynan, Andrew
Leech, Andrew Scheller, Artyom Skrobov, Asensio Lorenzo Sempere, Bradley
Wogsland, Cem Eliguzel, Chris Wilson, Christian Decker, Christian Zietz,
Christophe Priouzeau, Clayton Mills, Damien George, Daniel Jour, Daniël van
de Giessen, Dave Hylands, David Lechner, Emil Kondayan, Herwin Grobben,
iabdalkader, IhorNehrutsa, Jan, Jared Hancock, jason, Jeff Epler, Jeremy
Herbert, Jim Mussared, Jon Bjarni Bjarnason, Jonathan Hogg, Jos Verlinde,
Kattni Rembor, Lars Kellogg-Stedman, Luiz Brandao, marcidy, Martin Fischer,
Maureen Helm, Meriç SARIIŞIK, Michael Himing, Michael O'Cleirigh,
MikeTeachman, Peter D. Gray, Peter Hinch, Peter Züger, Phil Howard, Philipp
Ebensberger, Rob Knegjens, robert-hh, Sean Coates, Seon Rozenblum, Stephane
Smith, stijn, Takeo Takahashi, ubi de feo, Waterlens, wemos, YoungJoon
Chun, Yukai Li.

What follows is a detailed list of changes, generated from the git commit
history, and organised into sections.

Main components
===============

all:
- fix MICROPY_OBJ_REPR_D compilation with msvc
- update Python formatting to latest Black version 22.1.0
- use mp_obj_malloc everywhere it's applicable
- reformat remaining C code that doesn't have a space after a comma
- remove third argument to MP_REGISTER_MODULE
- rename MICROPY_PY_WIZNET5K to MICROPY_PY_NETWORK_WIZNET5K

py core:
- objstr: support '{:08}'.format("Jan") like Python 3.10
- modmath: add math.tau, math.nan and math.inf constants
- qstr: separate hash and len from string data
- qstr: use `const` consistently to avoid a cast
- gc: update debug code to compile with changes to qstr pool types
- rework bytecode and .mpy file format to be mostly static data
- bc.h: fix C++ compilation of public API
- objmodule: support delegating failed attr lookups
- modsys: add optional attribute delegation
- modsys: add optional sys.tracebacklimit attribute
- modsys: add optional mutable attributes sys.ps1/ps2 and use them
- parse: simplify handling of const int parse nodes
- parse: put const bytes objects in parse tree as const object
- parse: handle check for target small-int size in parser
- showbc: remove global variables and make DECODE_PTR work correctly
- smallint: introduce MP_SMALL_INT_BITS macro
- objgenerator: fix unused variables when native gen extracts prelude
- change jump opcodes to emit 1-byte jump offset when possible
- emitbc: add check for bytecode jump offset overflow
- change jump-if-x-or-pop opcodes to have unsigned offset argument
- builtinimport: alias sys to usys if import weak links aren't enabled
- bc.h: fix C++20 compilation with "volatile"
- compile: only show raw code that is bytecode
- asmxtensa: fix use of l32i/s32i when offset won't fit in encoding
- emitnative: don't store prelude at end of machine code if not needed
- vm: prevent array bound warning when using -MP_OBJ_ITER_BUF_NSLOTS
- runtime: allow multiple **args in a function call
- runtime: allow multiple *args in a function call
- runtime: do not overallocate when len is known
- runtime: drop new_alloc < 4 check
- runtime: use size_t/ssize_t instead of uint/int
- emitbc: assert that a small int fits its encoding when emitting one
- fix compiling and decoding of *args at large arg positions
- runtime: remove unnecessary check for kw_value == MP_OBJ_NULL
- makeqstrdefs: cleanup and extend source file classification
- emitinlinethumb: use 16 bit encodings for PUSH LR and POP PC
- scheduler: add support for scheduling static C-based callbacks
- emitnative: revert "don't store prelude at end of machine code if..."
- persistentcode: define enum values for obj types instead of letters
- parse: factor obj extract code to mp_parse_node_extract_const_object
- parse: print const object value in mp_parse_node_print
- parse: add MICROPY_COMP_CONST_TUPLE option to build const tuples
- persistentcode: support loading and saving tuples in .mpy files
- objtype: convert result of user __contains__ method to bool
- modsys: append MicroPython git version and build date to sys.version
- modsys: rename sys.implementation.mpy to sys.implementation._mpy
- modsys: introduce sys.implementation._machine constant
- emitcommon: don't implicitly close class vars that are assigned to
- obj: introduce mp_obj_malloc macro to allocate, and set object type
- objfloat: explain why mp_obj_malloc isn't used
- malloc: introduce m_tracked_calloc, m_tracked_free functions
- objmodule: move stray #include to top of file
- persistentcode: remove obsolete comment about qstr window size
- persistentcode: remove unicode feature flag from .mpy file
- asmx64: support full range of regs in asm_x64_lea_disp_to_r64
- bc: provide separate code-state setup funcs for bytecode and native
- emitnative: put a pointer to the native prelude in child_table array
- compile: allow new qstrs to be allocated at all compiler passes
- compile: de-duplicate constant objects in module's constant table
- parse: allow all constant objects to be used in "X = const(o)"
- makemoduledefs.py: allow multiple ways to register a module
- make builtin modules use MP_REGISTER_MODULE
- remove support for MICROPY_PORT_BUILTIN_MODULES
- asmthumb: fix PC relative load by sign extending the constant
- emitnative: simplify generation of code that loads prelude pointer
- emitnative: provide dedicated local for exception unwind handler ptr
- asmthumb: fix offset variable name in ldr, ldrh and strh functions
- asmthumb: add asm_thumb_ldrh_reg_reg_i12_optimised() helper func
- asmarm: add asm_arm_ldrh_reg_reg_offset() helper func
- asm: add ASM_LOAD16_REG_REG_OFFSET macro for load-u16 with offset
- emitnative: access qstr values using indirection table qstr_table
- asmthumb: make ARMv7-M instruction use dynamically selectable
- persistentcode: select ARMV6M as maximum when __thumb2__ not defined
- dynruntime.mk: add basic support for armv6m architecture
- asmthumb: provide implementations of clz/ctz for msvc
- builtin: clean up and simplify import_stat and builtin_open config
- emitinlinethumb: make ARMv7-M instruction use dynamically selectable
- emitinlinethumb: make float instruction use dynamically selectable
- change makemoduledefs process so it uses output of qstr extraction
- persistentcode: remove remaining native qstr linking support
- bc: remove unused mp_opcode_format function
- compile: give the compiler a hint about num nodes being non-zero
- makemoduledefs.py: remove shebang line and adjust style of comment
- parse: work around xtensa esp-2020r3 compiler bug
- dynruntime: add macros to create a new dict and store to dicts
- dynruntime: add macros to access more types and mp_const_empty_bytes
- makemoduledefs.py: emit useful error for legacy MP_REGISTER_MODULE

extmod:
- network_ninaw10: implement MP_STREAM_POLL in ioctl
- modusocket: make setsockopt return if NIC is not connected
- modusocket: add makefile() method and common socket options
- modusocket: create new sockets in blocking mode
- modusocket: support additional args to getaddrinfo
- machine_i2c: increase default SoftI2C timeout to 50ms
- modubinascii: add newline keyword to b2a_base64 function
- moduplatform: move platform PP definitions into a header
- moduzlib: fix parsing zlib header dict size
- moduos: create general uos module to be used by all ports
- modure: set subject begin_line so ^ doesn't match interior
- uasyncio: allow task state to be a callable
- uasyncio: fix gather cancelling and handling of exceptions
- extmod.cmake: add micropy_lib_mbedtls component
- modusocket: implement optional socket.listen backlog argument
- modusocket: provide config macro for socket.listen backlog deflt
- uasyncio: make Python Task match C version with use of asserts
- uasyncio: fix bug with task ending just after gather is cancel'd
- uasyncio: rename and merge TaskQueue push/pop methods
- move font_petme128_8x8.h from ports/stm32 to extmod
- make extmod modules use MP_REGISTER_MODULE
- make port-included extmod modules use MP_REGISTER_MODULES
- revert accidental usocket->socket rename
- webrepl: fix setting password in foreground mode and factor code
- modusocket: fix polling of a new socket
- modusocket: bind unconnected socket to default NIC in setsockopt
- modusocket: fix errcode returned from socket read/write
- modusocket: add socket type print function
- modusocket: add support for socket events callback
- modusocket: fix socket_make_new argument parsing
- modusocket: add timeout and callback to socket object
- modusocket: add sendall function
- network_ninaw10: add support for socket events callback
- machine_i2c: add optional support for write-then-read transfers
- uasyncio: fix edge case for cancellation of wait_for
- nimble: add support for reading whole HCI UART packets
- network_wiznet5k: add Wiznet Ethernet network interface
- modussl_mbedtls: poll EVENT_POLL_HOOK in ssl handshake loop
- modurandom: fix missing void in empty argument list
- extmod.cmake: require components to be explicitly enabled
- modusocket: add socket state to track new/listening/conn/closed
- modusocket: fix polling of closed sockets
- extmod.cmake: fix hard-coded mbedtls config file path

shared:
- readline: make tab insert an indent when it follows whitespace
- readline: disable auto-indent if space/tab follows added indent

drivers:
- ninaw10: add function to check socket state/data availability
- ninaw10: fix timeout handling to match modusocket
- ninaw10: return standard error numbers
- ninaw10: add NIC-level ioctl function
- sdcard: allow setting the final SPI baudrate
- codec: add driver for the WM8960 codec
- ninaw10: fix isconnected to return False when inactive
- dht/dht.py: change default import module as machine
- ninaw10: update driver to support firmware 1.5.0
- bus: rename MP_SPI_ADDR_IS_32B to MICROPY_HW_SPI_ADDR_IS_32BIT
- lsm6dsox: add support for SPI mode
- sdcard: fix CSD version 1.0 device size calculation
- sdcard: make ioctl(4), ioctl(5) return num blocks, block size
- sdcard: fix address calculation on v2 SDSC cards

mpy-cross:
- add armv6m architecture option

lib:
- re1.5: distinguish between subject start-of-line and start-of-srch
- stm32lib: update library for G0 v1.5.1
- fsp: add renesas fsp git repository as submodule
- littlefs: update littlefs2 to v2.5.0
- littlefs: guard lfs2_file_rawopen with LFS2_NO_MALLOC
- littlefs: remove assignment of variables to themselves
- nxp_driver: update nxp_driver to v2.10
- wiznet5k: add submodule for Wiznet Ethernet drivers

Support components
==================

docs:
- library: specify additional ADC methods and new ADCBlock class
- esp32: document expanded ADC API in quickref
- differences: update differences now that math.tau/inf/nan exist
- differences: update python_36 now that b2a_base64 accepts newline
- remove reference to obsolete neopixel_write function
- develop/porting.rst: fix build and import problems in the example
- reference/isr_rules.rst: fix inconsistent variable name in example
- esp32/quickref: update ADC documentation
- reference/isr_rules.rst: describe uasyncio-IRQ interface
- library/collections.rst: use class for deque and OrderedDict
- use the correct * keyword-only notation
- library/socket.rst: document socket as a class
- library/pyb.Timer.rst: add pyb.Timer class constants
- library/pyb.rst: add pyb.hid_mouse and pyb.hid_keyboard constants
- library/pyb.DAC.rst: add DAC class constants
- library/machine.SPI.rst: add class constant SoftSPI.MSB and .LSB
- library/machine.WDT.rst: use correct case for WDT.feed
- library/esp.rst: document the osdebug function
- library/pyb.SPI.rst: document default for prescaler argument
- library/machine.Pin.rst: document defaults for Pin.init
- library/uasyncio.rst: fix description of ThreadSafeFlag.wait
- library/machine.UART.rst: add details for `invert` parameter
- differences/python_35: mark PEP 486 as not applicable
- library/esp32.rst: mark esp32.Partition as not taking kw args
- esp32/quickref: document GPIO drive strength
- library/machine.Pin: update to use preferred DRIVE_x constants
- esp32/quickref: refine deep-sleep power-saving notes
- library/machine.I2S: clarify what rate refers to
- library/pyb.CAN: update CAN docs to match revised API
- add quickref and docs for mimxrt, including network.LAN docs
- reference/mpremote: add details about mount usage over soft reboot
- differences: update Python 3.5 diff, with optional listen backlog
- reference: update constrained docs now that tuples can be const
- library/network.WLAN: add "txpower" to list of known WLAN configs
- renesas-ra: add renesas-ra docs files
- update files for renesas-ra port
- renesas-ra: remove unused image files
- reference/mpyfiles: remove docs about mpy flags and qstr win size
- mimxrt: add i.MX RT1015 to general.rst, and a few clarifications
- mimxrt: move the pinout tables to a separate document
- reference/manifest: add link to details about opt-level for freeze
- reference/mpyfiles: update .mpy description to match latest format
- update Raspberry Pi URLs from .org to .com

examples:
- embedding: fix build with updated sys and os modules
- natmod/features3: add example to test more natmod features

tests:
- run-multitests.py: ignore lld_pdu_get_tx_flush_nb msgs from IDF
- run-multitests.py: set HOST_IP so tests work between PC and board
- multi_net: add testing key/cert to SSL server/client test
- multi_net: close accepted sockets when tests are done
- multi_net/udp_data.py: allow reusing port before bind
- multi_net/udp_data.py: make UDP test more reliable
- run-perfbench.py: allow a test to SKIP, and to have a .exp file
- perf_bench: add perf tests for qstr interning and importing .mpy
- perf_bench: add perf test for yield-from execution
- run-perfbench.py: use SKIP consistently, and increase print width
- extmod/vfs_fat_finaliser.py: make finalisation more robust
- run-tests.py: skip repl tests when running windows underneath
- perf_bench: skip bm_chaos test if random.randrange is unavailable
- unix: add coverage test for freezing various objects
- basics: add test for creating small-ints in nan-box builds
- run-tests.py: include test files ending in _set as set tests
- micropython: switch from set.pop to raise-0 to test exc strings
- extmod/vfs_posix.py: only test statvfs if it exists
- cmdline/cmd_showbc: fix spelling of sequence
- extmod: add test for machine.I2S data rate
- extmod: update I2S rate test to work on mimxrt
- basics/fun_callstardblstar: add coverage test
- basics/fun_callstardblstar: add test for large arg allocation
- pyb: update CAN tests to match revised CAN API
- inlineasm: add test for PUSH LR and POP PC
- perf_bench: update import tests for changes to .mpy consts
- micropython: add tests that const tuples don't use the heap
- extmod/uasyncio_gather: make double-raise gather test reliable
- run-tests.py: add timeout for running PC-based MicroPython test
- cmdline: add test for REPL auto-indent
- renesas-ra: add tests for renesas-ra port
- run-tests.py: update for renesas-ra port
- renesas-ra: remove unsupported feature test of Pin
- extmod: increase timing on uasyncio tests to make more reliable
- fix tests to use sys.implementation._mpy
- perf_bench: update .mpy file header to remove old unicode flag
- run-perfbench.py: return error code if any test fails on target
- thread: use less resources for stress_aes if settrace enabled
- run-tests.py: exclude settrace tests when using native emitter
- multi_net: skip SSL test if relevant modules aren't available
- micropython: fully unlink nested list in extreme exc test
- extmod: use bytearray instead of bytes for uctypes test
- micropython: add more test cases for native generators
- run-tests.py: allow running tests via mpy-cross on remote targets
- run-perfbench.py: allow running tests via mpy and native emitter
- basics: unlock heap if skipping nanbox small-int test
- run-tests.py: handle case where mpy-cross fails to compile script
- run-tests.py: enable `-X realtime` option for macOS tests
- extmod: change expected errno code from 36 to 30 in VfsLfs2 test
- multi_net: fix TCP accept test when using system error numbers
- run-multitests.py: use LAN for IP address if WLAN doesn't exist
- micropython: make import_mpy_native_gc run on ARMv6-M and above
- micropython: make import_mpy_native test run on all architectures
- run-tests.py: add rp2 test target
- move native while test from pybnative to micropython
- net_inet: remove broken api.telegram.org from tests
- run-multitests.py: read IP address from boot nic if available
- basics: add .exp file for sys.tracebacklimit test
- stress: adjust bytecode_limit test so it can SKIP if no memory

tools:
- mpremote: use machine instead of umachine in commands
- ci: test math constants with MICROPY_OBJ_REPR_D
- uf2conv.py: update to latest version
- autobuild: provide .uf2 images for esp32 builds when available
- mpremote: fix "fs cp -r" on Windows
- mpremote: make ConsolePosix work without .raw attribute
- mpremote: during soft reboot wait long enough for 115200 data
- mpremote: accept both --help and help to show usage
- mpremote: correctly manage mounted flag during soft-reset
- mpremote: fix special handling of ctrl-D when host FS is mounted
- verifygitlog.py: ignore line length in body if it's a URL
- ci.sh: update IDF v4.4 build to use v4.4 tag
- ci.sh: run urandom test scripts as part of native module tests
- mpremote: add "resume" and "soft-reset" commands
- mpremote: add "umount" command
- upip.py: remove unused op_basename() function
- mpy-tool.py: fix frozen comment generation to escape chars
- ci.sh: run performance benchmark as part of all unix test runs
- mpremote: bump version to 0.2.0
- gen-cpydiff: skip Black fmt comments
- mpremote: support any prompt string when detecting soft reset
- mpremote: allow running mpremote with `python -m`
- mpremote: improve reliability of mount after soft reboot
- mpremote: show progress indicator when copying large files
- mpremote: add option to mount cmd to allow "unsafe" symlinks
- mpy-tool.py: support loading tuples from .mpy files
- mpy-tool.py: support freezing tuples and other consts
- mpy-tool.py: optimise freezing of ints that can fit a small int
- mpy-tool.py: optimise freezing of empty str and bytes objects
- mpy-tool.py: make global qstr list a dedicated class
- mpy-tool.py: optimise freezing of str when str data is a qstr
- mpy-tool.py: intern more strings when freezing
- codeformat.py: remove ports/unix/*.py from exclusion list
- codeformat.py: include more ports .c/.h files in formatting
- ci.sh: don't run uasyncio_gather test on macOS
- ci.sh: update for ports/renesas-ra
- uncrustify: make sure a space exists after a comma
- autobuild: update for ports/renesas-ra
- mpy_ld.py: remove obsolete QSTR_WINDOW_SIZE constant
- ci.sh: run full test suite on stackless and settrace builds
- ci.sh: for esp8266 CI install esptool 3.3.1
- mpy-tool.py: remove obsolete unicode flag in .mpy header
- ci.sh: add build of W5100S_EVB_PICO board to rp2 CI
- mpy-tool.py: rework .mpy merging feature
- ci.sh: add test for mpy-tool's merging feature
- mpy-tool.py: improve generated frozen identifiers
- mpremote: add command to print the version
- mpremote: bump version to 0.3.0
- ci.sh: build NUCLEO_H743ZI with -O2 optimisation level
- mpy_ld.py: support R_XTENSA_PDIFF32 relocation
- ci.sh: build native .mpy examples for armv7emsp, xtensawin in CI
- mpy_ld.py: support GOT entries that reference inside mp_fun_table

CI:
- workflows: show context for qemu-arm test failures
- workflows: add new workflow to test .mpy file format and tools
- workflows: add new workflow to test embedding example
- workflows: add workflow for renesas-ra port

The ports
=========

all ports:
- consolidate inclusion of umachine module in built-ins
- recompile bytecode tests now that .mpy format changed
- allow boards to define additional network interfaces
- recompile bytecode tests now that .mpy format changed
- reformat more C and Python source code
- rename thread_t to mp_thread_t
- use default VFS config for import_stat and builtin_open

bare-arm port: no changes specific to this component/port

cc3200 port:
- make port-specific modules use MP_REGISTER_MODULE

esp8266 port:
- moduos: convert module to use extmod version
- mpconfigport.h: remove config values that are the defaults
- modesp: remove esp.info() function
- make port-specific modules use MP_REGISTER_MODULE
- machine_wdt: remove deinit method for watchdog
- etshal.h: remove unneeded function declaration

esp32 port:
- machine_adcblock: add new machine.ADCBlock class and update ADC
- pin MicroPython to core 1 again
- esp32_rmt: call rmt_driver_install directly if running on core 1
- main: allocate at most 1/2 of available IDF heap for MP heap
- README.md: fix URL for esp-idf installation
- modnetwork: fix test for WIFI_AUTH_MAX for IDF v4.3.0
- main: use heap_caps_get_info on IDF <4.1 to compute total heap
- boards: provide custom deploy_c3.md for ESP32-C3 boards
- partitions: increase size of app-part from 0x180000 to 0x1F0000
- machine_pwm: fix PWM not allowing frequencies < 611 Hz
- machine_pwm: clean up macro names and their use
- esp32_rmt: select correct last RMT channel on S2, S3, C3 variants
- main: automatically size SPIRAM heap when allocated using malloc
- adc: fix wrong mapping between ADC2 channel and GPIO number
- remove unneeded modesp.h
- create .uf2 binaries for S2 and S3 chips
- partitions-16MiB.csv: increase 14MiB filesystem to maximum size
- machine_adcblock: fix ADC bit width for ESP32-S3
- machine_adc: fix configuration of default ADC atten value
- boards: add three UM ESP32-S3 based boards
- mpconfigport.h: use the "extra" feature level
- mpconfigport.h: enable remaining features to get to "extra" level
- esp32_partition: add support for specifying block_size
- modules: create ffat partition object with block_size=512
- README.md: update list of supported IDF versions
- boards: add specific deploy instructions for S3 variant
- uart: correctly init low-level UART driver for REPL
- machine_uart: allow limited configuration of REPL UART
- sleep one tick in MICROPY_EVENT_POLL_HOOK
- machine_pwm: always set the duty cycle when setting the frequency
- machine_uart: make UART.init preserve unspecified parameters
- machine_pin: add support for pin drive strength
- moduos: convert module to use extmod version
- machine_pin: add new hold keyword argument and remove PULL_HOLD
- modesp32: add new gpio_deep_sleep_hold function
- boards/UM_TINYPICO: remove use of PULL_HOLD
- boards: add LOLIN C3 MINI ESP32-C3 based board
- machine_hw_spi: use automatic DMA channel selection for SPI on C3
- boards: add support for LilyGO LoRa32 boards
- machine_pin: expose pin 20 for ESP32
- allow overriding cmake frozen manifest from the command line
- boards: add test manifest to test freezing during build
- add MICROPY_HW_ENABLE_UART_REPL and enable on generic S2/S3
- boards: compile GENERIC_SPIRAM and UM_TINYPICO with -Os
- machine_pin: don't expose pins 33-37 when octal SPIRAM is enabled
- modesp32: properly define RTC_VALID_EXT_PINS on S2/S3 variants
- network_wlan: support setting/getting txpower in WLAN.config()
- modnetwork: fix build when MICROPY_PY_NETWORK_WLAN is disabled
- make port-specific modules use MP_REGISTER_MODULE
- boards/UM_FEATHERS3: use correct sdkconfig.board
- boards/LILYGO_TTGO_LORA32: remove ID from TTGO Lora32 board json
- machine_pin: fix ESP32C3 IDFv4.4.1 build
- track allocated iRAM and free it on soft reset
- machine_i2c: implement write-then-read I2C transfers
- machine_pin: only expose IO20 on esp32 for IDF 4.3.2 and above

javascript port:
- make port-specific modules use MP_REGISTER_MODULE

mimxrt port:
- support gaps in the SPI an I2C device numbers
- allow for board-specific flash driver files
- compensate for a bug in the fsl_lpspi.c file
- remove two files from the Seeed Arch Mix directory
- replace Pin-config constants by a function call
- allow to select cs0 or cs1 for SPI
- add USB ID elements
- add support for the Olimex RT1010 board
- simplify Makefile in selection of flash type
- machine_pin: change pin drive constants to DRIVE_x naming
- machine_spi: add omitted GPIO config
- boards: add board files for MIMXRT1015 and MIMXRT1015_EVK
- eth: fix an Ethernet transmit error
- boards/TEENSY41: use the same SPI1 pins for Teensy 4.0 and 4.1
- boards: support using an optional board-specific manifest.py
- eth: avoid a race condition for Ethernet
- hal/pwm_backport: make PWM symmetric, and round division calcs
- moduos: convert module to use extmod version
- mbedtls: add NULL pointer check in m_free_mbedtls
- machine_i2s: add I2S protocol support
- boards: add board.json file for OLIMEX RT1010Py
- modules: append /flash/lib to the default sys.path
- machine_rtc: start RTC at boot and set datetime if not set
- machine_spi: improve handling of busy SPI peripheral
- mphalport: fix USB CDC RX handling to not block when unprocessed
- mbedtls: use core-provided tracked alloc instead of custom funcs
- make port-specific modules use MP_REGISTER_MODULE
- boards/OLIMEX_RT1010: document the initial deploy procedure
- boards: extend the deploy_teensy.md instructions
- mphalport: fix strict aliasing error with unique id
- update port to work with new nxp_driver v2.10
- machine_uart: fix an inconsistency for UART.init() arg handling

minimal port: no changes specific to this component/port

nrf port:
- drivers/usb: fix background events/scheduling while at USB REPL
- drivers/usb: fix MP_STREAM_POLL_RD support on USB CDC
- modules: include uasyncio in default board manifest
- make port-specific modules use MP_REGISTER_MODULE
- mpconfigport: set MICROPY_CONFIG_ROM_LEVEL defines for each MCU
- mpconfigport: enable extra features as defined by ROM levels
- mpconfigport: fix MICROPY_VFS IO build support
- modules/uos/microbitfs: fix MICROPY_MBFS build to use mp_obj_malloc

pic16bit port:
- make port-specific modules use MP_REGISTER_MODULE
- use 1 byte for qstr hash len and include header to fix build

powerpc port: no changes specific to this component/port

qemu-arm port:
- add tests for freezing viper and asm_thumb code
- moduos: convert module to use extmod version
- test-frzmpy: add test for freezing constant tuples
- mpconfigport: define MICROPY_PY_SYS_PLATFORM

renesas-ra port:
- add new port to Renesas RA
- boards: change device name information to show properly
- rename pyb_uart_ to machine_uart_
- rename pyb_rtc_ to machine_rtc_
- make port-specific modules use MP_REGISTER_MODULE
- modmachine: add missing MP_REGISTER_MODULE for umachine
- machine_pin: remove code for unsupported Pin features

rp2 port:
- machine_i2c: provide more specific error codes from I2C transfer
- mpconfigport.h: use internal error numbers
- mphalport: add optional dupterm support
- machine_uart: add machine.UART init/deinit methods
- machine_i2c: use soft I2C only for len=0, and increase timeout
- modutime: fix time.localtime day-of-week value
- machine_uart: fix UART RTS behaviour so RTS is deasserted
- Makefile: add FROZEN_MANIFEST Makefile option, to override default
- mpthreadport: fix memory corruption when thread is created in core1
- add USB MSC support
- allow Overriding cmake frozen manifest from the command line
- enable ucryptolib, using mbedtls for backend functions
- mphalport: fix USB CDC RX handling to not block when unprocessed
- Makefile: add mbedtls to GIT_SUBMODULES list and use it in CI func
- machine_uart: use read/write mutex to prevent char duplication
- mpconfigport: enable execfile, NotImplemented and REPL EMACS keys
- make port-specific modules use MP_REGISTER_MODULE
- mpconfigport.h: enable static scheduler nodes
- mpconfigport.h: allow boards to override internal errno config
- boards/ARDUINO_NANO_RP2040_CONNECT: disable internal errno
- boards/ARDUINO_NANO_RP2040_CONNECT: enable webrepl
- mbedtls: add support for ssl module with MICROPY_SSL_MBEDTLS
- machine_pin: add mp_hal_pin_interrupt C interface
- Makefile: use cmake for "make submodules" task when needed
- integrate lwIP network stack
- add support for using Wiznet hardware as an Ethernet NIC
- boards/W5100S_EVB_PICO: add Wiznet W5100S-EVB-Pico board
- Makefile: build in debug mode with "make DEBUG=1"
- boards/ARDUINO_NANO_RP2040_CONNECT: update USB PID
- mpnetworkport: fix lwip alarm callback timing to use microseconds
- CMakeLists: simplify qstr sources when enabling extmod components

samd port:
- moduos: convert module to use extmod version
- make port-specific modules use MP_REGISTER_MODULE

stm32 port:
- mbedtls: enable MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE
- mboot: remove custom HAL_RCC_GetHCLKFreq and use HAL provided one
- pin: change remaining uses of "af" to "alt"
- dac: deinit all DACs on soft reset
- fdcan: fix FIFO1 usage and handling of error interrupts
- fdcan: fix naming with regards to G4 series
- usbd_conf: set lpm_enable and battery_charging_enable on all MCUs
- powerctrlboot: set HAL uwTickPrio variable when needed
- powerctrl: write bootloader-state as 64-bit word to work on H7
- mboot: use PLL3 for USB clock source on H7 MCUs
- mboot: include hal_rcc_ex.c in source file list
- mboot: support H7 MCUs in fwupdate.py
- mboot: compute and check CRC32 of dfu file in fwupdate.py
- add support for G4 MCUs, and add NUCLEO_G474RE board defn
- mboot: allow HSI to be used as the main clock source
- mboot: add MBOOT_BOARD_ENTRY_INIT for a board to add entry code
- mboot: add support for F469/479 MCUs in fwupdate.py
- rtc: use LL_RTC functions to simplify some MCU-specific code
- Makefile: make stm32lib configurable
- add initial support for STM32WL MCUs
- boards/NUCLEO_WL55: add new board definition
- system_stm32: make SystemClock_Config() a weak symbol
- adc: fix L4 ADC channel numbers
- adc: remove obsolete FIRST/LAST GPIO channel macros
- boards/NUCLEO_L432KC: disable MICROPY_OPT_COMPUTED_GOTO
- boards/NUCLEO_WB55: add Arduino pin alias definitions
- mboot: allow a board to fully configure system clocks
- mboot: allow a board more control over entry initialisation
- moduos: convert module to use extmod version
- boards: convert F4xx and F7xx to new flash FS config
- mbedtls: add NULL pointer check in m_free_mbedtls
- sdcard: use mp_hal_pin_input instead of HAL function
- sdcard: add sdcard_select_sd/mmc functions
- main: support SD cards without a partition table
- dma: add option to disable auto-DMA-turn-off
- mboot: add pragma for GCC to ignore array bounds warning
- mboot: always check the magic number to enter filesystem loading
- mboot: add support for 64-bit mboot address space for reads
- mboot: add support for reading from SD card
- boards/PYBD_SF2: turn on SD card in mboot init if SD enabled
- mboot/fwupdate.py: simplify calculation of CRC32
- mboot: verify signature of fsload packed DFU files before writing
- mboot: verify CRC32 of fsload DFU files before writing
- support building for STM32F745
- machine_i2s: set FullDuplexMode to disabled on F4
- machine_i2s: allow I2S.deinit to be called multiple times
- machine_i2s: fix 16-bit stereo i2s_frame_map
- sdio: use runtime calculation for clock divider of sdio on H7
- modmachine: add deepsleep support to reset_cause() for WB55
- pyb_can: enable CAN FD frame support and BRS
- pyb_can: add support for CAN FD extended frame ID
- pyb_can: add support for bus with mixed Classic/FD nodes
- pyb_can: return the filter ID and type of received messages
- pyb_can: define the maximum bit timing parameters
- pyb_can: replace CAN.initfilterbanks with CAN.init keyword arg
- Makefile: allow overriding COPT in Makefile
- mpconfigport.h: let MICROPY_PY_IO_FILEIO take its default value
- machine_bitstream: include all clobbered regs in Cortex-M0 impl
- mboot: consolidate all UI and add general state change hooks
- mboot: add macros for use in led_state_all()
- sdram: add function to enable SDRAM power-down mode
- Makefile: add H747 to Makefile's MCU flags
- system_stm32: add H7 switched-mode-power-supply support
- system_stm32: set voltage scaling level 0 for H7 Rev-V devices
- system_stm32: allow boards to configure PLL VCI, VCO and FRACN
- system_stm32: improve H7 PLL and OSC configuration
- boards/PYBD_SFx: allow FROZEN_MANIFEST to be overridden
- mpbthciport: switch scheduling callback to use node scheduler
- boards/SPARKFUN_MICROMOD_STM32: fix incorrect UART and I2C config
- mphalport: fix I/O glitches when switching GPIO mode to alt-func
- boards/ADAFRUIT_F405_EXPRESS: use external SPI flash for storage
- boards/LEGO_HUB_NO6: exclude BTstack code from formatting
- qspi: support common flash sizes in MPU configuration
- qspi: wait for a free FIFO location before writing to DR
- qspi: workaround for SR set immediately after setting AR
- ulpi: add USB3320 ULPI low-power functions
- ulpi: include missing py/mperrno.h header
- boards/ARDUINO_PORTENTA_H7: add support for Arduino Portenta H7
- storage: add support for internal storage on Cortex-M0 MCUs
- add support for G0 MCUs
- boards/NUCLEO_G0B1RE: add NUCLEO_G0B1RE board definition
- mbedtls: use core-provided tracked alloc instead of custom funcs
- make port-specific modules use MP_REGISTER_MODULE
- rfcore: revert "intercept addr-resolution HCI cmd to work arou..."
- mboot: move remaining led_state_all call into mboot_state_change
- mboot: add update_app_elements to return mboot fsload elements
- mboot: make 0x70ad0000 values named constants with macros
- mboot: pass initial_r0 to early-init and get-reset-mode funcs
- boards/LEGO_HUB_NO6: make all SPI flash transfers use 32-bit addr
- boards/LEGO_HUB_NO6: add support for mboot to access SPI flash
- boards/LEGO_HUB_NO6: use multi-colour LED for mboot status
- boards/LEGO_HUB_NO6: implement robust filesystem-load updates
- boards/LEGO_HUB_NO6: add helper scripts to update app firmware
- rfcore: remove extra layer of buffering on BLE IPCC
- flash: remove FLASH_OPTR_DBANK condition in L4, H7 get_bank func
- machine_i2c: enable timingr constructor keyword on H7 MCUs
- powerctrl: disable sys tick interrupt in stop mode on some STM32s
- usbd_conf: remove disable of SYSCFG clock
- mboot: add board-configurable SysTick hook
- mboot: remove MP_WEAK on led funcs and make some of them static
- boards/LEGO_HUB_NO6: add comment to readme about powering off
- mboot: only include UI code if at least one board LED is defined

teensy port:
- make port-specific modules use MP_REGISTER_MODULE
- mpconfigport.h: remove obsolete macros

unix port:
- Makefile: remove explicit addition of -std=c++ flag
- show compiler info in REPL banner
- .gitignore: remove *.py from ignore list
- moduos: convert module to use extmod version
- mpconfigport.h: collect together config options from extra level
- variants: use rom feature config for standard, dev, coverage
- variants: enable a few optimisations and features on dev, coverage
- make port-specific modules use MP_REGISTER_MODULE
- implement `-X realtime` command-line option on macOS
- factor out code that generates random bytes to a new func
- variants: enable seeding random module on import in dev, coverage

windows port:
- README.md: fix broken mingw link
- add micropython.schedule support
- mingw: include extmod/shared/lib sources properly
- uselect: enable micropython select in dev variant
- uasyncio: add support for uasyncio to windows dev variant
- appveyor: fix printing of test failures
- Makefile: specify CXXFLAGS in the Makefile
- unify project file headers
- switch to VFS subsystem and use VfsPosix
- consolidate all sleep-related functions into windows_mphal.c
- avoid busy loop when using scheduler
- use BCryptGenRandom to implement os.urandom
- factor out code that generates random bytes to a new func

zephyr port:
- update include path to disk_access.h
- upgrade to Zephyr v3.0.0
- prj.conf: enable CONFIG_BUILD_OUTPUT_HEX to generate .hex output
- moduos: convert module to use extmod version
- make port-specific modules use MP_REGISTER_MODULE
- modusocket: fix function object wrapper for listen method

Boosted performance, board.json metadata, more mimxrt, rp2, samd features

This release of MicroPython sees a boost to the overall performance of the
VM and runtime.  This is achieved by the addition of an optional cache to
speed up general hash table lookups, as well as a fast path in the VM for
the LOAD_ATTR opcode on instance types.  The new configuration options are
MICROPY_OPT_MAP_LOOKUP_CACHE and MICROPY_OPT_LOAD_ATTR_FAST_PATH.  As part
of this improvement the MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE option has
been removed, which provided a similar map caching mechanism but with the
cache stored in the bytecode, which made it not useful on bare metal ports.
The new mechanism is measured to be at least as good as the old one,
applies to more map lookups, has a constant RAM overhead, and applies to
native code as well as bytecode.

These performance options are enabled on the esp32, mimxrt, rp2, stm32 and
unix ports.  For esp32 and mimxrt some code is also moved to RAM to further
boost performance.  On stm32, performance increases by about 20% for
benchmarks that are heavy on name lookups, like misc_pystone.py and
misc_raytrace.py.  On esp32 performance can increase by 2-3x, and on mimxrt
it is up to 6x.

All boards in all ports now have a board.json metadata file, which is used
to automatically build firmware and generate a webpage for that board
(among other possibilities).  Auto-build scripts have been added for this
purpose and they build all esp32, mimxrt, rp2, samd and stm32 boards.  The
generated output is available at https://micropython.org/download.

Support for FROZEN_DIR and FROZEN_MPY_DIR has been deprecated for some time
and was finally removed in this release.  Instead of these, FROZEN_MANIFEST
can be used.  The io.resource_stream() function is also removed, replaced
by the pure Python version in micropython-lib.

The search order for importing frozen Python modules is now controlled by
the ".frozen" entry in sys.path.  This string is added by default in the
second position in sys.path.  User code should adjust sys.path depending on
the desired behaviour.  Putting ".frozen" first in sys.path will speed up
importing frozen modules.

A bug in multiple precision integers with bitwise of -0 was fixed in commit
2c139bbf4e5724ab253b5b034ce925e04267a9c4.

The platform module has been added to allow querying the compiler and
underlying SDK/HAL/libc version.  This is enabled on esp32, mimxrt and
stm32 ports.

The mpremote tool now supports seek, flush, mkdir and rmdir on PC-mounted
filesystems.  And a help command has been added.

The documentation has seen many additions and improvements thanks (for a
second time) to the Google Season of Docs project.  The rp2 documentation
now includes a reference for PIO assembly instructions, a PIO quick
reference and a PIO tutorial.  The random and stm modules have been
documented, along with sys.settrace, manifest.py files and mpremote.  There
is also now more detail about the differences between MicroPython and
standard Python 3.5 and above.

The esp32 port sees support for ESP32-S3 SoCs, and new boards GENERIC_S3,
ESP32_S2_WROVER, LOLIN_S2_MINI, LOLIN_S2_PICO and UM_FEATHERS2NEO.  The PWM
driver has been improved and now supports all PWM timers and channels, and
the duty_u16() and duty_ns() methods, and it keeps the duty constant when
changing frequency.  The machine.bitstream() function has been improved to
use RMT, with an option to select the original bit-banging implementation.

The mimxrt port gained new hardware features: SDRAM and SD card support, as
well as network integration with a LAN driver.  The machine.WDT class was
added along with the machine.reset_cause(), machine.soft_reset(),
machine.unique_id() add machine.bitstream() functions.  DHT sensor support
was added, and f-strings were enabled.

The rp2 port now has support for networking, and bluetooth using NimBLE.
The Nina-W10 WiFi/BT driver is fully integrated and supported by the new
Arduino Nano RP2040 connect board.  I2S protocol support is added along
with a machine.bitstream() driver and DHT sensor support.  The PWM driver
had a bug fix with the accuracy of setting/getting the frequency, and the
duty value is now retained when changing the frequency.

On the samd port there is now support for the internal flash being a block
device, and for filesystems and the os module.  Pin and LED classes have
been implemented.  There are more time functions, more Python features
enabled, and the help() function is added.  SEEED_WIO_TERMINAL and
SEEED_XIAO board definitions are now available.

The stm32 port now has support for F427, F479 and H7A3(Q)/H7B3(Q) MCUs, and
new board definitions for VCC_GND_H743VI, OLIMEX_H407, MIKROE_QUAIL,
GARATRONIC_PYBSTICK26_F411, STM32H73B3I_DK.  A bug was fixed in the SPI
driver where a SPI transfer could fail if the CYW43 WiFi driver was also
active at the same time.

On the windows port the help() function has been enabled, and support for
build variants added, to match the unix port.

The zephyr port upgraded Zephyr to v2.7.0.

The change in code size since the previous release for various ports is
(absolute and percentage change in the text section):

       bare-arm:  -1520  -2.605%
    minimal x86:  -2256  -1.531%
       unix x64:   -457  -0.089%
    unix nanbox:   -925  -0.204%
          stm32:   +312  +0.079% PYBV10
         cc3200:   -176  -0.096%
        esp8266:   +532  +0.076% GENERIC
          esp32: +27096  +1.820% GENERIC
            nrf:   -212  -0.121% pca10040
            rp2:  +9904  +2.051% PICO
           samd: +35332 +33.969% ADAFRUIT_ITSYBITSY_M4_EXPRESS

The changes that dominate these numbers are:
- bare-arm, minimal: use of new MICROPY_CONFIG_ROM_LEVEL_MINIMUM option and
  subsequent disabling of remaining optional features
- unix, cc3200, nrf: general code size reductions of the core
- stm32: performance improvements, addition of platform module
- esp8266: enabling f-strings
- esp32: use of -O2 instead of -Os
- rp2: machine.I2S and other new hardware features
- samd: filesystem support and other new hardware features

Thanks to everyone who contributed to this release: Alan Dragomirecký,
Alexey Shvetsov, Andrew Leech, Andrew Scheller, Antoine Aubert, Boris
Vinogradov, Chris Boudacoff, Chris Fiege, Christian Decker, Damien George,
Daniel Gorny, Dave Hylands, David Michieli, Emilie Feral, Frédéric Pierson,
gibbonsc, Henk Vergonet, iabdalkader, Ihor Nehrutsa, Jan Hrudka, Jan Staal,
jc_.kim, Jim Mussared, Jonathan Hogg, Laurens Valk, leo chung, Lorenzo
Cappelletti, Magnus von Wachenfeldt, Matt Trentini, Matt van de Werken,
Maureen Helm, Michael Bentley, Michael Buesch, Mike Causer, Mike Teachman,
Mike Wadsten, Ned Konz, NitiKaur, oli, patrick, Patrick Van Oosterwijck,
Peter Boin, Peter Hinch, Peter van der Burg, Philipp Ebensberger, Pooya
Moradi, retsyo, robert-hh, roland van straten, Scott Armitage, Sebastian
Wicki, Seon Rozenblum, Sergei Silnov, Simon Baatz, Stewart Bonnick, stijn,
Tobias Thyrrestrup, Tomas Vanek, YoungJoon Chun.

What follows is a detailed list of changes, generated from the git commit
history, and organised into sections.

Main components
===============

all:
- remove MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE
- update Python formatting to latest Black version 21.12b0
- remove support for FROZEN_DIR and FROZEN_MPY_DIR

py core:
- parse: simplify parse nodes representing a list
- emitnative: ensure load_subscr does not clobber existing REG_RET
- mpconfig.h: define initial templates for "feature levels"
- vm: add a fast path for LOAD_ATTR on instance types
- map: add an optional cache of (map+index) to speed up map lookups
- builtinimport: forward all debug printing to MICROPY_DEBUG_PRINTER
- add wrapper macros so hot VM functions can go in fast code location
- runtime: fix crash when exc __new__ doesn't return an exc instance
- mpconfig.h: define the "extra" feature level
- mpconfig.h: revert MICROPY_REPL_INFO to disabled at all levels
- gc: add hook to run code during time consuming GC operations
- showbc: print unary-op string when dumping bytecode
- modsys: replace non-ASCII quote char with ASCII char
- runtime: allow types to use both .attr and .locals_dict
- lexer: support nested [] and {} characters within f-string params
- objfun.h: remove obsolete comments about entries in extra_args
- builtinimport: refactor module importing
- showbc: fix printing of raw bytecode header on nanbox builds
- modio: remove io.resource_stream function
- only search frozen modules when '.frozen' is found in sys.path
- mkrules.cmake: set frozen preprocessor defs early
- runtime: allow initialising sys.path/argv with defaults
- mpstate.h: only include sys.path/argv objects in state when enabled
- mpz: fix bugs with bitwise of -0 by ensuring all 0's are positive
- qstr: reset mpstate.qstr_last_chunk before raising an error
- modbuiltins: add additional macro for extending builtins
- mpconfig.h: define MICROPY_PY_USSL_FINALISER only if not defined

extmod:
- machine_i2c: make SoftI2C configurable via macro option
- machine_spi: make SoftSPI configurable via macro option
- modonewire: make _onewire module configurable via macro option
- machine_pwm: factor out machine.PWM bindings to common code
- move modnetwork and modusocket from stm32 to extmod
- modnetwork: add STA_IF and AP_IF constants
- modnetwork: add extended socket state
- modusocket: add read/write stream methods to socket object
- modnetwork: define network interfaces in port config files
- network_cyw43: make consistent use of STA and AP constants
- modnetwork: remove STM32 references
- modnetwork: remove modnetwork socket u_state member
- mpbthci.h: add mp_bluetooth_hci_uart_any prototype
- nimble: add nimble CMake fragment file
- add platform module
- moduplatform: improve implementation for PC ports
- vfs_posix_file: support MP_STREAM_POLL in vfs_posix_file_ioctl
- modbluetooth: add connection interval to gap_connect
- nimble: update to NimBLE v1.4
- nimble: remove workaround for OS_ENOMEM
- uasyncio: fix gather returning exceptions from a cancelled task
- uplatform: remove unused definitions
- uplatform: use generic custom platform string
- network_ninaw10: fix scan list order to match other NICs
- modbluetooth: support gap_connect(None) to cancel a connection
- modure: redirect regex debug printing to mp_printf
- network_ninaw10: fix config of AP mode
- network_ninaw10: disable active connections before connecting
- network_ninaw10: make NIC state persistent
- network_ninaw10: return -1 on timeout from recv/send
- network_ninaw10: make recv/recvfrom interchangeable
- moduplatform: detect xtensa arch
- modusocket: allow setting timeout on unbound sockets
- modusocket: initialise accepted socket state
- network_ninaw10: use socket timeout preset in modusocket
- modbluetooth: fix conditional compilation of ringbuf_put_uuid
- modbluetooth: put declaration of connect_cancel in correct place

shared:
- libc/string0: don't include string.h, and provide __memcpy_chk
- runtime/pyexec: cleanup EXEC_FLAG flag constants

drivers:
- ninaw10: add ublox Nina-W10 WiFi/BT module driver
- lsm6dsox: add LSM6DSOX driver and examples
- neopixel: avoid heap alloc in fill()
- ninaw10: fix BSSID byte order, and add null byte to ESSID
- ninaw10/nina_wifi_drv: fix DNS resolution

mpy-cross: no changes specific to this component/port

lib:
- mynewt-nimble: switch to the MicroPython fork of NimBLE
- asf4: point submodule to latest commit on circuitpython branch
- update pico-sdk to 1.3.0 and tinyusb to 0.12.0
- stm32lib: update library for L4 v1.17.0, new G4, WL, and MMC fixes
- stm32lib: update library for fix to F7 USB HS

Support components
==================

docs:
- library/os.rst: clarify littlefs requirements for block erase
- library/bluetooth.rst: update incorrect link to gatts_write
- make.bat: change Windows output dir from '_build' to 'build'
- library/machine.I2S.rst: specify that I2S.shift args are kw-only
- esp32: explain ESP32 PWM modes, timers, and channels
- rp2: add reference for PIO assembly instructions, and PIO tutorial
- library/random.rst: document the random module
- reference/mpremote.rst: add docs for mpremote
- reference/manifest.rst: add docs for manifest.py files
- library/stm.rst: document the stm module
- esp32/tutorial: add an example of peripheral control via regs
- rp2/general.rst: fix typo with missing spaces
- library/framebuf.rst: adjust dimensions in example
- library/rp2.rst: update function asm_pio_encode to add sideset_opt
- reference/filesystem.rst: add detail on how to use littlefs fuse
- rp2/quickref.rst: add section on PIO
- library/sys.rst: add docs for sys.settrace
- esp8266/tutorial: fix comments of FrameBuffer examples
- library/uasyncio.rst: detail exception behaviour in cancel/timeout
- library/machine.Timer.rst: document 'id' as positional-only arg
- library/machine.SPI.rst: add example SPI usage
- library/machine.Timer.rst: document `period` and `callback` args
- library/machine.Pin.rst: add Pin.ANALOG mode constant
- remove trailing spaces and convert tabs to spaces
- library/sys.rst: add note about '.frozen' as an entry in sys.path
- differences: document details of new PEPs/features in Python 3.5+
- update copyright year range to include 2022
- esp32: update RMT quickref example to match latest code

examples: no changes specific to this component/port

tests:
- perf_bench: use math.log instead of math.log2
- basics: add tests for type-checking subclassed exc instances
- micropython/const.py: add comment about required config for test
- cpydiff: clarify f-string diffs regarding concatenation
- basics/int_big_cmp.py: add more tests for big-int comparison
- extmod: skip uselect_poll_udp when poll() is not available

tools:
- autobuild: add auto build for GENERIC_C3_USB
- ci.sh: use IDF v4.4 as part of esp32 CI and build GENERIC_S3
- autobuild: add the MIMXRT1010_EVK board to autobuild
- ci.sh: use a specific ESP IDF v4.4 commit
- autobuild: add script to generate website board metadata
- dfu.py: make tool work with python3 when parsing DFU files
- autobuild: automatically build all mimxrt, rp2 and samd boards
- autobuild: automatically build all stm32 boards
- mpremote: implement seek and flush in ioctl method
- autobuild: automatically build all esp32 boards
- upip.py: support == to specify exact package version
- makemanifest.py: make str conversion compatible with Python 2
- makemanifest.py: merge make-frozen.py
- mpremote: add mkdir and rmdir to RemoteFS
- mpremote: add help command
- mpremote: add link to mpremote docs URL in help message
- upip.py: skip '.frozen' entry in sys.path for install path
- autobuild: build esp8266 OTA image with GENERIC_1M board
- ci.sh: upgrade Zephyr docker image to v0.21.0
- ci.sh: build zephyr nucleo_wb55rg to test zephyr bluetooth build

CI:
- workflows: use Python 3.8 for macos workflow
- workflows: add new workflow to build ports download metadata

The ports
=========

all ports:
- add board.json for all boards
- add images, features and urls to board.json
- add '.frozen' as the first entry in sys.path
- move '.frozen' to second entry in sys.path

bare-arm port:
- mpconfigport.h: use MICROPY_CONFIG_ROM_LEVEL_MINIMUM
- mpconfigport.h: disable remaining optional features

cc3200 port: no changes specific to this component/port

esp8266 port:
- boards/GENERIC: enable f-strings
- extract qstr from object when comparing keys in config()
- etshal.h: remove unneeded function declarations
- allow building a board to any dest directory

esp32 port:
- boards: add new FeatherS2-Neo board definition
- machine_timer: use tx_update member for IDF 4.4 and above
- add support for ESP32-S3 SoCs
- boards: add new GENERIC_S3 board definition
- machine_hw_spi: fix hardware SPI DMA channels for S2/S3
- boards: add board definition for ESP32-S2-WROVER module
- boards: add LOLIN_S2_MINI ESP32-S2 board
- machine_pwm: add support for all PWM timers and channels
- README: updated readme with req IDF vers for ESP32-S2, C3 and S3
- usb: add USB host connection detection for CDC serial output
- machine_pin: block out IO16 and IO17 when using SPIRAM on ESP32
- mpthreadport: fix TCB cleanup function so thread_mutex is ready
- main: add option for a board to hook code into startup sequence
- split out WLAN code from modnetwork.c to network_wlan.c
- enable optimisations and move code to iRAM to boost performance
- usb: improve speed of USB CDC output
- add specific deploy_s2.md instructions for esp32-s2
- boards/LOLIN_S2_MINI: add image to board.json
- boards: update board and deploy metadata for UM_xxx boards
- usb: further improve speed of USB CDC output
- boards/LOLIN_S2_PICO: add LOLIN_S2_PICO board definition files
- boards/ESP32_S2_WROVER: link to specific deploy_s2 instructions
- support building with latest IDF v5
- in machine_i2s, send null samples in underflow situations
- in machine_i2s, make object reference arrays root pointers
- add SDCard support for S3, and a GENERIC_S3_SPIRAM board
- boards/GENERIC_S3: enable BLE on ESP32 S3
- machine_pwm: implement duty_u16() and duty_ns() PWM methods
- extract qstr from object when comparing keys in config()
- machine_pin: make GPIO 26 usable for S2,S3 if SPIRAM not config'd
- machine_hw_spi: fix SPI default pins reordering on ESP32-S2/S3
- machine_hw_spi: set proper default SPI(id=1) pins on S2,S3 and C3
- machine_hw_spi: set proper default SPI(id=2) pins on S2 and S3
- boards: remove SPI pin defaults from GENERIC S2/S3 boards
- modnetwork: synchronize WiFi AUTH_xxx constants with IDF values
- machine_pwm: keep duty constant when changing frequency
- machine_bitstream: replace bit-bang code with RMT-based driver
- machine_i2s: add support for ESP-IDF 4.4
- machine_bitstream: fix signal duplication on output pins
- esp32: enable platform module with IDF version
- boards/GENERIC_D2WD: build with -Os optimisation
- esp32_rmt: install RMT driver on core 1
- machine_bitstream: reinstate bitstream bit-bang implementation

javascript port: no changes specific to this component/port

mimxrt port:
- sdcard: implement SDCard driver
- machine_bitstream: add bitstream function to machine module
- rework flash configuration
- sdram: add SDRAM support
- eth: add LAN support and integrate the network module
- modmachine: implement machine.WDT() and machine.reset_cause()
- boards: fix the D14/D15 pin assignment of MIMXRT1050/60/64_EVK
- hal: remove duplicate definitions from flexspi_hyper_flash.h
- dma_channel: fix the DMA channel management
- fix cycle counter for time.ticks_cpu() and machine.bitstream()
- add dht_readinto() to the mimxrt module, and freeze dht.py
- extend the help() message and README.md
- mpconfigport.h: enable f-strings
- modmachine: implement soft_reset() and unique_id() functions
- boards/make-pins.py: allow empty lines and comments in pins.csv
- optimize the runtime speed
- enable the platform module
- boards: add the Seeed ARCH MIX board
- boards: update the board.json files and add deploy_xx.md files
- fix mp_hal_quiet_timing_enter()/exit() so timer still runs
- support PWM using the FLEXPWM and QTMR modules
- define UART 0 on MIMXRT boards
- support selection of PHY type and address
- re-enable eth checksum creation by HW
- fix a tiny unnoticed bug in sdcard.c
- add a driver for the DP83848 PHY device
- refactor the reading of the machine id
- enable ticks_cpu at boot time for NDEBUG builds only
- use -Og instead of -O0 for DEBUG builds
- tidy up the board flash related files
- hal: allow readSampleClkSrc to be configured by a board
- enable MICROPY_PY_USSL_FINALISER

minimal port:
- mpconfigport.h: use MICROPY_CONFIG_ROM_LEVEL_MINIMUM
- Makefile: don't force a 32-bit build
- mpconfigport.h: disable features that are not needed

nrf port:
- Makefile: improve Black Magic Probe commands
- main: use VFS helper function to mount fs and chdir

pic16bit port: no changes specific to this component/port

powerpc port: no changes specific to this component/port

qemu-arm port: no changes specific to this component/port

rp2 port:
- mpconfigport.h: enable heapq module
- add support for bluetooth module using NimBLE
- add framework for networking
- mpconfigport.h: use the "extra" feature level
- enable optimisations (comp goto, map cache, fast attr)
- machine_i2s: add I2S protocol support
- add support for Nina-W10 WiFi/BT module
- boards: add support for Arduino Nano RP2040
- machine_bitstream: implement the machine.bitstream driver
- boards: add neopixel.py to manifest.py
- rp2_pio: support exec with sideset
- boards/PIMORONI_PICOLIPO_16MB: fix 16MB flash size
- boards: add PYBSTICK26 RP2040 board definition
- machine_uart: handle and clear UART RX timeout IRQ
- boards/ARDUINO_NANO_RP2040_CONNECT: set default I2C pins
- machine_pwm: fix PWM frequency setting
- machine_pwm: keep duty value when changing the frequency
- add support for DHT11 and DHT22 sensors
- CMakeLists.txt: allow a board to override PICO_BOARD
- boards/GARATRONIC_PYBSTICK26_RP2040: use correct pico-sdk board cfg

samd port:
- integrate latest asf4, add help, more time funcs and uPy features
- samd_soc: allow a board to configure the low-level MCU config
- add internal flash block device, filesystem and uos support
- add Pin and LED classes, and machine.unique_id
- boards/ADAFRUIT_FEATHER_M0_EXPRESS: update for flash and pins
- boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS: update for flash and pins
- boards/MINISAM_M4: update for flash and pins
- boards/ADAFRUIT_TRINKET_M0: update for flash and pins
- boards/SAMD21_XPLAINED_PRO: update for flash and pins
- boards/SEEED_WIO_TERMINAL: add new board definition
- boards/SEEED_XIAO: add new board definition
- README.md: update README to reflect new features and boards

stm32 port:
- pin: enable GPIO clock of pin if it's constructed without init
- main: don't unconditionally enable GPIO A,B,C,D clocks
- boards/VCC_GND_H743VI: add board definition for VCC_GND_H743VI
- boards/OLIMEX_E407: add Ethernet RMII support
- boards/LEGO_HUB_NO6: remove user paths from cc2564 init file
- boards: remove trailing spaces, and add newline at end of file
- add basic support for STM32H750
- add support for H7A3(Q)/H7B3(Q), and STM32H73B3I_DK board defn
- suggest putting code in main.py not boot.py
- boards/make-pins.py: allow a CPU pin to be hidden
- boards/make-pins.py: allow empty lines and comments in pins.csv
- dma: add functions for external users of DMA to enable clock
- enable LOAD_ATTR fast path, and map lookup caching on >M0
- boards: add OLIMEX H407 board definition
- enable platform module
- extended flash filesystem space to 512K on H743 boards
- boards/NUCLEO_H743ZI: enable VfsLfs2 on NUCLEO_H743ZI(2) boards
- boards: add PF11-BOOT0 to stm32f091_af.csv
- machine_i2c: use hardware I2C for STM32H7
- sdram: enforce gcc opt, and use volatile and DSB in sdram_test
- usbd_cdc_interface: allow a board to hook into USBD CDC RX events
- mpbthciport: allow a board to hook BT HCI poll functions
- pendsv: allow a board to add entries for pendsv_schedule_dispatch
- boards: add images to board.json for Adafruit and VCC_GND boards
- uart: fix race conditions and clearing status in IRQ handler
- mpconfigport.h: use the "extra" feature level
- in machine_i2s, send null samples in underflow situations
- in machine_i2s, make object reference arrays root pointers
- led: support an extra 2 LEDs in board configuration
- boards/MIKROE_CLICKER2_STM32: add more detail to board.json
- boards: add new board MikroElektronika Quail, and F427 support
- main: run optional frozen module at boot
- sdio: don't explicitly disable DMA2 on deinit of SDIO
- dma: make DMA2_Stream3 exclusive to SDIO when CYW43 enabled
- boards: build NUCLEO_WB55 and STM32F769DISC without mboot enabled
- boards: add PYBSTICK26 F411 board definition
- boards/NADHAT_PYBF405: rename board to GARATRONIC_NADHAT_F405
- usb: use a table of allowed values to simplify usb_mode get/set
- boards/NUCLEO_WB55: update rfcore_firmwre for new WS
- flashbdev: support generic flash storage config via link symbols
- boards: convert F413,F439,H743,L4xx,WB55 to new flash FS config
- add support for F479 MCUs
- include HAL MMC code in F4 builds
- boards/make-pins.py: use cpu pins to define static alt-fun macros
- boards/NUCLEO_WB55: fix LED ordering
- boards/LEGO_HUB_NO6: set filesystem label as HUB_NO6
- boards: remove stray '+' characters at start of lines in ld files
- boards: remove unused MICROPY_HW_ENABLE_TIMER config
- boards: enable MICROPY_HW_ENABLE_SERVO on various boards
- update L4 code to build with latest stm32lib and L4 HAL 1.17.0
- main: call sdcard_init when only MICROPY_HW_ENABLE_MMCARD enabled
- sdcard: support 8-bit wide SDIO bus
- sdcard: add config option to force MM card capacity
- factoryreset: init vfs flags before calling pyb_flash_init_vfs
- qspi: fix typo in address comment
- boards/make-pins.py: generate empty ADC table if needed
- boards/OLIMEX_H407: fix typo in OLIMEX H407 board.json
- network_wiznet5k: fix build error with wiznet5k and lwip enabled
- enable MICROPY_PY_USSL_FINALISER

teensy port:
- switch to use manifest.py instead of FROZEN_DIR

unix port:
- enable LOAD_ATTR fast path, and map lookup caching
- modusocket: support MP_STREAM_POLL in unix socket_ioctl
- modos: add support for uos.urandom(n)
- coverage: change remaining printf to mp_printf
- Makefile: use -Og instead of -O0 for debug builds

windows port:
- README: remove unsupported Python instructions for Cygwin
- mpconfigport.h: enable help and help("modules")
- add support for build variants to windows port
- run tests via Makefile
- appveyor: build both standard and dev variants
- appveyor: build mpy-cross only once for mingw-w64
- msvc: run qstr preprocessing phase in parallel

zephyr port:
- mphalport.h: remove unused and unimplemented C-level pin API
- increase minimum CMake version to 3.20.0
- update include path to reboot.h
- get UART console device from devicetree instead of Kconfig
- use CONFIG_USB_DEVICE_STACK for conditional USB device support
- upgrade to Zephyr v2.7.0
- modbluetooth_zephyr: provide dummy connect_cancel function