KPDPI
#define MPPDPI KPDPI
#define KERNBASE KVADDR(KPML4I + NKPML4E - 1, KPDPI, 0, 0)
i = (NKPML4E - 1) * NPDPEPG + KPDPI;
for (j = 0; j < NPDPEPG - KPDPI; ++j) {
nkpt_base = (NPDPEPG - KPDPI) * NPTEPG; /* typically 2 x 512 */
kpd_base = allocpages(firstaddr, NPDPEPG - KPDPI);