HelenOS sources

bitmap_set        421 kernel/generic/src/mm/frame.c 		bitmap_set(&zone->bitmap, index, 0);
bitmap_set        507 kernel/generic/src/mm/frame.c 		bitmap_set(&zones.info[z1].bitmap, i,
bitmap_set        513 kernel/generic/src/mm/frame.c 		bitmap_set(&zones.info[z1].bitmap, base_diff + i,
HelenOS homepage, sources at GitHub