HelenOS sources

ZONE_FIRMWARE     106 kernel/arch/amd64/src/mm/frame.c 			    ZONE_FIRMWARE);
ZONE_FIRMWARE     106 kernel/arch/ia32/src/mm/frame.c 			    ZONE_FIRMWARE);
ZONE_FIRMWARE     200 kernel/generic/src/ddi/ddi.c 	if (zones.info[znum].flags & (ZONE_FIRMWARE | ZONE_RESERVED)) {
ZONE_FIRMWARE    1313 kernel/generic/src/mm/frame.c 		    (flags & ZONE_FIRMWARE) ? 'F' : '-',
ZONE_FIRMWARE    1424 kernel/generic/src/mm/frame.c 	    (flags & ZONE_FIRMWARE) ? 'F' : '-',
HelenOS homepage, sources at GitHub