L2_BASE
#define L2_BASE ((pd_entry_t *)((char *)L1_BASE + L4_SLOT_PTE * NBPD_L3))
#define L2_BASE ((pd_entry_t *)((char *)L1_BASE + L4_SLOT_PTE * NBPD_L3))
#define L2_BASE ((pd_entry_t *)((char *)L1_BASE + L2_SLOT_PTE * NBPD_L1))