p4_entry_t
PT4 = (p4_entry_t *)0x0000000040000000;
PT4[i] = (p4_entry_t)PT3;
static p4_entry_t *PT4;
uint64_t modulep, p4_entry_t *pagetable,
extern p4_entry_t PT4[];
PT4[i] = (p4_entry_t)VTOP((uintptr_t)&PT3[0]);