If I understood everything correct, osmocombb project consist of all the code for GSM stack L1-L3 functionality but Calypdo DSP code is not Opensource and layer1.bin ask non-opensource DSP module to do execute L1 tasks from ghis list:

Of cource we can patch DSP and ask it to do whatever we want, like send raw bursts to the host, but now osmocombb uses mostly DSP firmware written by Texas Instruments, not its own opdnsource.

Is it correct or not?

Thanks in advance!