This is a custom STM32F1xx/STM32F4xx bootloader that allows flashing firmware binaries via USB, using DFU or HID-flash protocols. The -ambitious- intention behind the project is to implmenet the intricacies of many more STM32 MCUs into a single project that can be easily downloaded, configured, compiled and flashed.

Flashing new firmware with minimal interaction with the physical board is really convenient in some cases. In my case, it was flashing my 3d printer's BTT GTR 1.0 board through my OctoPi at the press of a button (two actually, reset + LCD encoder button), which I can now trigger via RPi's GPIO and flash at will, without any manual interaction.

This bootloader is a work in progress, meaning it has not been tested widely, and there is still a lot to consider on hardware compatibility. Please consider this as something experimental, until you've made sure all aspects work on your specific board.

The project was inspired by Serasidis/STM32_HID_Bootloader (which originates from bootsector/stm32-hid-bootloader) and retains compatibility with the hid-flash tool.

The project is adapted to PlatformIO (the project should build and upload as is, provided you have an ST-Link/v2 device connected). It uses the original STM32Cube framework libraries instead of containing slightly modified parts of it. DFU protocol is implemented and tested on both STM32F1xx/4xx platforms. For the moment, compatibility with the older version of HID-Flash.exe is maintained only in STM32F4xx compilation. HID-flash tool's sources are not included in the project.

Before you try this, be absolutely sure that you have a copy of the original bootloader of your board, which you have successfully flashed back to the board without problems.

Customizing the bootloader behavior is done by modifying the Configuration.h file. See file comments for details.

Use an ST-Link compatible device, properly connected to your board and the PC. Use PlatformIO's upload command to install. Resetting the board with BOOT0 pin set to 3.3V should also work, but this depends on your board and MCU (check the wiki for more info on the subject).

Enable the configured trigger and reset the board (in case of pin trigger, keep the pin enabled while resetting and until the USB device appears at the host. Depneding on which protocol you have enabled (DFU or HID), use dfu-util.exe or hid-flash.exe cmd line tool to upload a firmware binary file manually, or if your firmware project is a PlatformIO project, simply configure dfu or hid as your preferred upload-protocol in the env section of your firmware's platformio.ini file, like in the following example:

#
# Bigtreetech GTR V1.0 (STM32F407IGT6 ARM Cortex-M4)
#
[env:BIGTREE_GTR_V1_0]
extends            = stm32_variant
board              = marlin_BigTree_GTR_v1
board_build.offset = 0x8000
build_flags        = ${stm32_variant.build_flags} -DSTM32F407IX
upload_protocol    = dfu

Visit the wiki for more info on flashing and using.

More triggers, more flashing methods, more STM32 MCUs / boards to support.

So far, the project has been tested on the following boards:

STM32F4XX:

• BigTreeTech GTR 1.0 (STM32F407IGT6)

STM32F1XX:

• HR0214-32 development board (STM32F103C8T6)