pmap_preboot_get_vpages
dpcpu = pmap_preboot_get_vpages(DPCPU_SIZE / PAGE_SIZE);
irqstack = pmap_preboot_get_vpages(IRQ_STACK_SIZE * MAXCPU);
abtstack = pmap_preboot_get_vpages(ABT_STACK_SIZE * MAXCPU);
undstack = pmap_preboot_get_vpages(UND_STACK_SIZE * MAXCPU );
kernelstack = pmap_preboot_get_vpages(kstack_pages);
msgbufp = (void *)pmap_preboot_get_vpages(
vm_offset_t pmap_preboot_get_vpages(u_int);