+extern void __pg_mount_point;
+
+/* 四个页挂载点,两个页目录挂载点: 用于临时创建&编辑页表 */
+#define PG_MOUNT_RANGE(l1_index) (701 <= l1_index && l1_index <= 703)
+#define PD_MOUNT_1 (MMIO_BASE + MEM_4MB)
+#define PG_MOUNT_BASE (PD_MOUNT_1 + MEM_4MB)
+#define PG_MOUNT_1 (PG_MOUNT_BASE)
+#define PG_MOUNT_2 (PG_MOUNT_BASE + 0x1000)
+#define PG_MOUNT_3 (PG_MOUNT_BASE + 0x2000)
+#define PG_MOUNT_4 (PG_MOUNT_BASE + 0x3000)
+
+#define PD_REFERENCED L2_BASE_VADDR