CHIP_IO_SYS_START
abst->abst_sys_start = CHIP_IO_SYS_START(v);
abst->abst_sys_end = CHIP_IO_SYS_START(v) + abst->abst_bus_end;
ioaddr = ioh - ALPHA_PHYS_TO_K0SEG(CHIP_IO_SYS_START(v));