This is currently the firmware I use for the BIQU B1 with the B2 (2 in 1 hotend) with an SKR2 Board (f407 chip) and TMC2225(2208) drivers and BLtouch. Driver jumpers need to be placed in UART mode. Reference image for UART mode.
It is set up with BLtouch for homming
* Double check and Set up yor own Probe offsets
* Z-endstop switch should be diabled/removed to prevent damage