diff --git a/lib/xlat_tables/aarch64/xlat_tables.c b/lib/xlat_tables/aarch64/xlat_tables.c
index 309cb9b..4125651 100644
--- a/lib/xlat_tables/aarch64/xlat_tables.c
+++ b/lib/xlat_tables/aarch64/xlat_tables.c
@@ -8,66 +8,19 @@
 #include <arch_helpers.h>
 #include <assert.h>
 #include <bl_common.h>
-#include <cassert.h>
 #include <common_def.h>
 #include <platform_def.h>
 #include <sys/types.h>
 #include <utils.h>
 #include <xlat_tables.h>
+#include <xlat_tables_arch.h>
 #include "../xlat_tables_private.h"
 
-/*
- * Each platform can define the size of the virtual address space, which is
- * defined in PLAT_VIRT_ADDR_SPACE_SIZE. TCR.TxSZ is calculated as 64 minus the
- * width of said address space. The value of TCR.TxSZ must be in the range 16
- * to 39 [1], which means that the virtual address space width must be in the
- * range 48 to 25 bits.
- *
- * Here we calculate the initial lookup level from the value of
- * PLAT_VIRT_ADDR_SPACE_SIZE. For a 4 KB page size, level 0 supports virtual
- * address spaces of widths 48 to 40 bits, level 1 from 39 to 31, and level 2
- * from 30 to 25. Wider or narrower address spaces are not supported. As a
- * result, level 3 cannot be used as initial lookup level with 4 KB
- * granularity. [2]
- *
- * For example, for a 35-bit address space (i.e. PLAT_VIRT_ADDR_SPACE_SIZE ==
- * 1 << 35), TCR.TxSZ will be programmed to (64 - 35) = 29. According to Table
- * D4-11 in the ARM ARM, the initial lookup level for an address space like
- * that is 1.
- *
- * See the ARMv8-A Architecture Reference Manual (DDI 0487A.j) for more
- * information:
- * [1] Page 1730: 'Input address size', 'For all translation stages'.
- * [2] Section D4.2.5
- */
+#define XLAT_TABLE_LEVEL_BASE	\
+       GET_XLAT_TABLE_LEVEL_BASE(PLAT_VIRT_ADDR_SPACE_SIZE)
 
-#if PLAT_VIRT_ADDR_SPACE_SIZE > (1ULL << (64 - TCR_TxSZ_MIN))
-
-# error "PLAT_VIRT_ADDR_SPACE_SIZE is too big."
-
-#elif PLAT_VIRT_ADDR_SPACE_SIZE > (1ULL << L0_XLAT_ADDRESS_SHIFT)
-
-# define XLAT_TABLE_LEVEL_BASE	0
-# define NUM_BASE_LEVEL_ENTRIES	\
-		(PLAT_VIRT_ADDR_SPACE_SIZE >> L0_XLAT_ADDRESS_SHIFT)
-
-#elif PLAT_VIRT_ADDR_SPACE_SIZE > (1 << L1_XLAT_ADDRESS_SHIFT)
-
-# define XLAT_TABLE_LEVEL_BASE	1
-# define NUM_BASE_LEVEL_ENTRIES	\
-		(PLAT_VIRT_ADDR_SPACE_SIZE >> L1_XLAT_ADDRESS_SHIFT)
-
-#elif PLAT_VIRT_ADDR_SPACE_SIZE >= (1 << (64 - TCR_TxSZ_MAX))
-
-# define XLAT_TABLE_LEVEL_BASE	2
-# define NUM_BASE_LEVEL_ENTRIES	\
-		(PLAT_VIRT_ADDR_SPACE_SIZE >> L2_XLAT_ADDRESS_SHIFT)
-
-#else
-
-# error "PLAT_VIRT_ADDR_SPACE_SIZE is too small."
-
-#endif
+#define NUM_BASE_LEVEL_ENTRIES	\
+       GET_NUM_BASE_LEVEL_ENTRIES(PLAT_VIRT_ADDR_SPACE_SIZE)
 
 static uint64_t base_xlation_table[NUM_BASE_LEVEL_ENTRIES]
 		__aligned(NUM_BASE_LEVEL_ENTRIES * sizeof(uint64_t));