This repo is cross-platform UF2 Bootloader projects for MCUs based on TinyUSB
.
├── apps # Useful applications such as self-update, erase firmware
├── lib # Sources from 3rd party such as tinyusb, mcu drivers ...
├── ports # Port/family specific sources
│ ├── espressif
│ │ └── boards/ # Board specific sources
│ │ └── Makefile # Makefile for this port
│ └── mimxrt10xx
├── src # Cross-platform bootloader sources files
Supported features are
- Double tap to enter DFU, reboot to DFU and quick reboot from application
- DFU with MassStorage (MSC)
- Self update with uf2 file
- Indicator: LED, RGB, TFT
- Debug log with uart/swd
Not all features are implemented for all MCUs, following is supported MCUs and its feature
| MCU | MSC | Double Reset | Self-update | Write Protection | Neopixel | TFT |
|---|---|---|---|---|---|---|
| ESP32 S2/S3 | ✔ | Need RC | ✔ | ✔ | ✔ | |
| K32L2 | ✔ | ✔ | ||||
| LPC55 | ✔ | ✔ | ✔ | |||
| iMXRT | ✔ | ✔ | ✔ | ✔ | ||
| STM32F3 | ✔ | ✔ | ✔ | |||
| STM32F4 | ✔ | ✔ | ✔ | ✔ | ✔ |
Following is generic compiling information. Each port may require extra set-up and slight different process e.g esp32s2 require setup IDF.
To build this for a specific board, we need to change current directory to its port folder
$ cd ports/stm32f4
Then compile with make BOARD=[board_name] all, for example
make BOARD=feather_stm32f405_express all
The required mcu driver submodule if any will be clone automatically if needed.
flash target will use the default on-board debugger (jlink/cmsisdap/stlink/dfu) to flash the binary, please install those support software in advance. Some board use bootloader/DFU via serial which is required to pass to make command
$ make BOARD=feather_stm32f405_express flash
If you use an external debugger, there is flash-jlink, flash-stlink, flash-pyocd which are mostly like to work out of the box for most of the supported board.
To compile for debugging add DEBUG=1, this will mostly change the compiler optimization
$ make BOARD=feather_stm32f405_express DEBUG=1 all
Should you have an issue running example and/or submitting an bug report. You could enable TinyUSB built-in debug logging with optional LOG=.
- LOG=1 will print message from bootloader and error if any from TinyUSB stack.
- LOG=2 and LOG=3 will print more information with TinyUSB stack events
$ make BOARD=feather_stm32f405_express LOG=1 all
By default log message is printed via on-board UART which is slow and take lots of CPU time comparing to USB speed. If your board support on-board/external debugger, it would be more efficient to use it for logging. There are 2 protocols:
LOGGER=rtt: use Segger RTT protocol- Cons: requires jlink as the debugger.
- Pros: work with most if not all MCUs
- Software viewer is JLink RTT Viewer/Client/Logger which is bundled with JLink driver package.
LOGGER=swo: Use dedicated SWO pin of ARM Cortex SWD debug header.- Cons: only work with ARM Cortex MCUs minus M0
- Pros: should be compatible with more debugger that support SWO.
- Software viewer should be provided along with your debugger driver.
$ make BOARD=feather_stm32f405_express LOG=2 LOGGER=rtt all
$ make BOARD=feather_stm32f405_express LOG=2 LOGGER=swo all