LEGACYIO_PAGE_WIDTH 48 kernel/arch/ia64/include/arch/legacyio.h #define LEGACYIO_SIZE (1ULL << LEGACYIO_PAGE_WIDTH) LEGACYIO_PAGE_WIDTH 530 kernel/arch/ia64/src/mm/tlb.c if ((va >= LEGACYIO_USER_BASE) && (va < LEGACYIO_USER_BASE + (1 << LEGACYIO_PAGE_WIDTH))) { LEGACYIO_PAGE_WIDTH 532 kernel/arch/ia64/src/mm/tlb.c uint64_t io_page = (va & ((1 << LEGACYIO_PAGE_WIDTH) - 1)) >>HelenOS homepage, sources at GitHub