_BUS_VM_PAGE_TO_BUS
#if !defined(_BUS_VM_PAGE_TO_BUS)
busaddr = _BUS_VM_PAGE_TO_BUS(pg) + offset;
curaddr = lastaddr = segs[curseg].ds_addr = _BUS_VM_PAGE_TO_BUS(m);
curaddr = _BUS_VM_PAGE_TO_BUS(m);