To build the example you need to bring your own clang and lld, also you need wchisp. I used clang 23.
cd example/cmake/blink
cmake -B build -G Ninja -DCMAKE_TOOLCHAIN_FILE="./toolchains"
cmake --build build
llvm-objcopy -O binary --only-section=.init --only-section=.vector --only-section=.text --only-section=.fini --only-section=.preinit_array --only-section=.init_array --only-section=.fini_array --only-section=.ctors --only-section=.dtors --only-section=.dlalign --only-section=.data --only-section=.got build/main ./build/main.bin
sudo /home/mccakit/dev/tooling/wchisp/bin/wchisp flash build/main.bin
SDK files(Drivers link scripts etc) are from https://github.com/openwch/ch32v307 so is the FreeRTOS
LLVM libc, compiler-rt and libcxx are distributed in binary form in this sdk