proof of concept bts

Hi list,   Regarding the interesting video from Russia(Positive hacking days 2012) where Sylvain demonstrates av proof of concept bts, is it a dsp patch of the osmocombb firmware before one uploads to the c123 phones that one has to  do? The tasks then are modified in this patch or also elsewhere? And then one removes and replaces a tranceiver-code in openbts sourcecode?    [I have tried the tacooper version of osmo-bts but that that code-approach is for the sysmo-bts, althoug the osmocombb phone proof of concept bts is mentioned in the tacooper thesis online]     Regards Erich