HelenOS sources

sdctl1_run        193 uspace/drv/audio/hdaudio/stream.c 		ctl = ctl | BIT_V(uint8_t, sdctl1_run);
sdctl1_run        195 uspace/drv/audio/hdaudio/stream.c 		ctl = ctl & ~BIT_V(uint8_t, sdctl1_run);
HelenOS homepage, sources at GitHub