This fork of a-culfw contains some cherry picks in order to make the project compilable again.
If you found this repository through Google, because you tried compiling the original a-culfw project and got erros like the one below, give this fork a try.
/usr/local/Cellar/arm-none-eabi-gcc/10.3-2021.07/gcc/bin/../lib/gcc/arm-none-eabi/10.3.1/../../../../arm-none-eabi/bin/ld: section .ARM.exidx LMA [000000000011c47c,000000000011c483] overlaps section .relocate LMA [000000000011c47c,000000000011c9eb]
collect2: error: ld returned 1 exit status
make[1]: *** [CUBE_BL.elf] Error 1
make: *** [CUBE_BL] Error 2
The original fimware is cloned from www.culfw.de (thanks for the work to R.K.)
This alternative firmware has additional send receive methods and code cleanups. The compiled firmware can be found at MediaFire