Are there actually any open gsm capable chips? I'd expect there to be other transmitted codes for certain functionality which isn't as readily documented but still abuseable.
TI Calypso, with OsmocomBB[1]. Haven't you seen the link you're commenting under? :P
[1] of course all feature and legal restrictions apply, so don't get too excited about "yay free baseband finally!". It's a amazing research project nevertheless, which together with OpenBSC already gave us incredible insights on GSM security. All hail Harald Welte! \o/
