HelenOS sources

ZONE_EF_MASK       89 kernel/generic/include/mm/frame.h 	(((((zf) & ZONE_EF_MASK)) == ((f) & ZONE_EF_MASK)) && \
ZONE_EF_MASK       90 kernel/generic/include/mm/frame.h 	    (((zf) & ~ZONE_EF_MASK) & (f)))
HelenOS homepage, sources at GitHub