trunc_4mpage
pv_npg = trunc_4mpage(vm_phys_segs[vm_phys_nsegs - 1].end -
va = trunc_4mpage(va);
va = trunc_4mpage(va);
sva = trunc_4mpage(va);
firstpte = &KPTmap[i386_btop(trunc_4mpage(va))];
pagezero((void *)&KPTmap[i386_btop(trunc_4mpage(va))]);
firstpte = pmap_pte_quick(pmap, trunc_4mpage(va));
tmpva = trunc_4mpage(tmpva) + NBPDR;
tmpva = trunc_4mpage(tmpva) + NBPDR;