Swindle CH32V3x DFU bootloader

This is a "small" bootloader for the CH32V3x chips from WCH. It takes about 13 kB and is being built on top of tinyUSB.

The downloaded application must be linked to be at 0x4000 (i.e. base +16 kB)

There are several ways to enter DFU:

There is a signature in ram upon reboot (0xDEADBEEFCC00FFEEULL at the beginning of RAM)
The pin PB2 is pulled down to ground
The signature of the main firmware is invalid

Firmware signature

The layout is as follows :

If firmware size is 0x1234 and xxhash is 0x5678, the hash check is skipped.

Edit platformConfig to point for your toolchain.

The one i use is a recent version of clang/riscv32 with picolibc.

dfu-util -d 1d50:6030  -s 0x0004000:leave -D binaryfile

Name		Name	Last commit message	Last commit date
Latest commit History 59 Commits
.vscode		.vscode
lnArduino @ 2ab52db		lnArduino @ 2ab52db
lnArduino_mini		lnArduino_mini
src		src
.clang-format		.clang-format
.clang-tidy		.clang-tidy
.gitignore		.gitignore
.gitmodules		.gitmodules
.pre-commit-config.yaml		.pre-commit-config.yaml
CMakeLists.txt		CMakeLists.txt
LICENSE		LICENSE
README.md		README.md
build_default.cmake		build_default.cmake
dfu_test.sh		dfu_test.sh
dfu_update.txt		dfu_update.txt
flash_config.h.in		flash_config.h.in
mcuSelect.cmake		mcuSelect.cmake
platformConfig.cmake		platformConfig.cmake
tiny.cmake		tiny.cmake