Extended STM32 Support

[code-fiasco]

Pull Request: Full STM32 Support and Reliable DFU Entry

TL;DR

• Adds multi-family STM32 support: F1xx, F4xx, G4xx, and WB55
• Automatic USB initialization and task polling for supported families
• Serial automatically aliased to SerialTinyUSB
• Software DFU entry overhauled for reliability:
  • F1/F4/G4: direct ROM bootloader jump
  • WB55: magic value in BKP0R + NVIC_SystemReset() with early Reset_Handler interception
• WB55-specific support via dfu_boot_stm32wb.c
• Nucleo-64 board definitions supported for F1/F4/G4 variants
• Expanded hardware testing: WeAct STM32G431, G474, STM32F411/405, WB55 Nucleo boards

Notes:

• Generic WB55 variants without a USB clock configuration are not supported
• STM32F1 DFU still requires validation on boards with factory bootloader
• No changes were made to other architectures

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Full Detailed Description

Summary

This PR extends the Adafruit TinyUSB Arduino library to support a broader range of STM32 MCUs and adds reliable software DFU for all supported boards. It consolidates functionality previously implemented in separate updates (v0.2.0 and v0.3.0).

Added

• STM32 Family Support
  • F1 (tested on STM32F103 BluePill)
  • F4 (WeAct STM32F411/405)
  • G4 (WeAct STM32G431/G474)
  • WB55 (WeAct STM32WB55CGU6 using P-NUCLEO-WB55 / NUCLEO WB55 USB Dongle board definitions)
• Automatic USB initialization via initVariant()
• Automatic TinyUSB task polling using HAL_IncTick() override and serialEventRun() hook
• Automatic aliasing of Serial to SerialTinyUSB
• Software DFU entry:
  • F1/F4/G4: direct ROM bootloader jump after disabling interrupts and resetting clocks
  • WB55: writes magic value to RTC backup register (BKP0R), triggers NVIC_SystemReset(), intercepted by dfu_boot_stm32wb.c at Reset_Handler
• Nucleo-64 board definitions now supported for F1/F4/G4 variants as a side effect of WB55 support

Changed

• DFU implementation rewritten for reliability across families
• boards.txt entries updated: four lines per board (including use_1200bps_touch and wait_for_upload_port)
• boards_txt_additions.txt updated to reflect new format and include Nucleo-64 entry

Testing

• F1: STM32F103 BluePill (USB works; DFU untested on clone boards)
• F4: WeAct STM32F411/405
• G4: WeAct STM32G431/G474
• WB55: P-NUCLEO-WB55, NUCLEO WB55 USB Dongle

Known Limitations

• Generic WB55 variants without proper USB clock configuration are not supported. Full generic support would require a PLLSAI1Q 48 MHz USB clock setup in the STM32duino core.
• STM32F1 DFU entry requires further validation on boards with factory bootloader.
• Adding support to Nucleo-64 means that TinyUSB will show as an option for some Nucleo boards that aren't yet supported.

Notes

• This PR builds on the existing STM32 TinyUSB support, extending it to additional families and boards.
• WB55 DFU implementation ensures reliable bootloader entry without affecting normal boot behavior.
• No changes were made to other architectures.
• These changes consolidate prior experimental updates (v0.2.0 and v0.3.0 functionality) into a single, complete STM32 port.

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Suggested Testing / Validation Checklist

Suggested Testing / Validation Checklist

• USB enumeration works on all supported STM32 boards (F1xx, F4xx, G4xx, WB55)
• CDC, MIDI, HID, MSC USB classes function correctly
• Sketches using Serial alias to SerialTinyUSB behave as expected
• Software DFU entry works reliably:
  • WB55: triggers bootloader via magic value + reset
  • F1/F4/G4: triggers ST ROM bootloader after direct jump
• Nucleo-64 board definitions work with TinyUSB option in Arduino IDE
• boards.txt auto-upload (use_1200bps_touch + wait_for_upload_port) functions correctly
• Normal boot is unaffected when DFU is not triggered

[Copilot]

Pull request overview

Extends the STM32 Arduino port to support additional STM32 families (F1/F4/G4/WB) with automatic USB init/task servicing, and introduces a WB-specific DFU entry path via early reset interception.

Changes:

• Auto-detect STM32 family in TinyUSB config and adjust class/buffer defaults.
• Add automatic TinyUSB initialization (initVariant) and background servicing (HAL_IncTick flag + yield()/serialEventRun()).
• Implement WB55 software DFU entry via backup-register “magic” + custom Reset_Handler, plus documentation updates for STM32duino boards.txt integration.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/arduino/ports/stm32/tusb_config_stm32.h	Adds STM32 family autodetection and updates TinyUSB configuration for the STM32 port.
src/arduino/ports/stm32/Adafruit_TinyUSB_stm32.cpp	Implements multi-family STM32 USB HW init, automatic init/task pumping, and DFU entry logic.
src/arduino/ports/stm32/dfu_boot_stm32wb.c	Adds WB reset-time DFU interception and bootloader jump.
src/arduino/ports/stm32/boards_txt_additions.txt	Documents STM32duino boards.txt menu additions needed to enable TinyUSB.
README.md	Updates documentation for STM32 and other cores without built-in support.

Comments suppressed due to low confidence (1)

src/arduino/ports/stm32/boards_txt_additions.txt:22

• The WB55 note says the Nucleo-64 definitions are “covered by the Nucleo_64 entry above”, but the Nucleo_64.menu.usb.TinyUSB... lines are below this comment in the file. Please fix the wording (“below”) so the instructions are unambiguous.

# Generic WB55 variants lack USB clock configuration and will not enumerate.
# Use the P-NUCLEO-WB55 or NUCLEO WB55 USB Dongle board definition instead
# (covered by the Nucleo_64 entry above). Custom WB55 boards with a 32MHz
# HSE crystal should also work with these definitions.

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[code-fiasco]

Assuming esp32_v2 fail is unrelated like last time? I've submitted pr to STM32 to get boards.txt additions. Next goal is to add F0xx support and then I'm probably done for a while until someone requests something specific, can't keep buying microcontrollers! lol