BA_UNMAPPED
gbflags = (flags & BA_UNMAPPED) != 0 ? GB_UNMAPPED : 0;
gbflags = (flags & BA_UNMAPPED) != 0 ? GB_UNMAPPED : 0;
gbflags = (flags & BA_UNMAPPED) != 0 ? GB_UNMAPPED : 0;
flags |= BA_UNMAPPED;