diff --git a/arch/x86/cpu/broadwell/sdram.c b/arch/x86/cpu/broadwell/sdram.c
index c104a84..1295121 100644
--- a/arch/x86/cpu/broadwell/sdram.c
+++ b/arch/x86/cpu/broadwell/sdram.c
@@ -25,7 +25,7 @@
 #include <asm/arch/pei_data.h>
 #include <asm/arch/pm.h>
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	return mrc_common_board_get_usable_ram_top(total_size);
 }
diff --git a/arch/x86/cpu/coreboot/sdram.c b/arch/x86/cpu/coreboot/sdram.c
index 4a256ba..f4ee4cd 100644
--- a/arch/x86/cpu/coreboot/sdram.c
+++ b/arch/x86/cpu/coreboot/sdram.c
@@ -27,7 +27,7 @@
  * address, and how far U-Boot is moved by relocation are set in the global
  * data structure.
  */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	uintptr_t dest_addr = 0;
 	int i;
diff --git a/arch/x86/cpu/efi/payload.c b/arch/x86/cpu/efi/payload.c
index b777856..1c28a43 100644
--- a/arch/x86/cpu/efi/payload.c
+++ b/arch/x86/cpu/efi/payload.c
@@ -27,7 +27,7 @@
  * the relocation address, and how far U-Boot is moved by relocation are
  * set in the global data structure.
  */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	struct efi_mem_desc *desc, *end;
 	struct efi_entry_memmap *map;
diff --git a/arch/x86/cpu/efi/sdram.c b/arch/x86/cpu/efi/sdram.c
index af65982..f3086db 100644
--- a/arch/x86/cpu/efi/sdram.c
+++ b/arch/x86/cpu/efi/sdram.c
@@ -11,7 +11,7 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	return (ulong)efi_get_ram_base() + gd->ram_size;
 }
diff --git a/arch/x86/cpu/intel_common/mrc.c b/arch/x86/cpu/intel_common/mrc.c
index a97b0b7..a4918fb 100644
--- a/arch/x86/cpu/intel_common/mrc.c
+++ b/arch/x86/cpu/intel_common/mrc.c
@@ -25,7 +25,7 @@
 	"active"
 };
 
-ulong mrc_common_board_get_usable_ram_top(ulong total_size)
+phys_size_t mrc_common_board_get_usable_ram_top(phys_size_t total_size)
 {
 	struct memory_info *info = &gd->arch.meminfo;
 	uintptr_t dest_addr = 0;
@@ -50,7 +50,7 @@
 
 	dest_addr = largest->start + largest->size;
 
-	return (ulong)dest_addr;
+	return (phys_size_t)dest_addr;
 }
 
 void mrc_common_dram_init_banksize(void)
diff --git a/arch/x86/cpu/ivybridge/sdram.c b/arch/x86/cpu/ivybridge/sdram.c
index dd6b875..1a0ec43 100644
--- a/arch/x86/cpu/ivybridge/sdram.c
+++ b/arch/x86/cpu/ivybridge/sdram.c
@@ -44,7 +44,7 @@
 #define CMOS_OFFSET_MRC_SEED_S3		156
 #define CMOS_OFFSET_MRC_SEED_CHK	160
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	return mrc_common_board_get_usable_ram_top(total_size);
 }
diff --git a/arch/x86/cpu/qemu/dram.c b/arch/x86/cpu/qemu/dram.c
index c174550..595c397 100644
--- a/arch/x86/cpu/qemu/dram.c
+++ b/arch/x86/cpu/qemu/dram.c
@@ -71,7 +71,7 @@
  * the relocation address, and how far U-Boot is moved by relocation are
  * set in the global data structure.
  */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	return qemu_get_low_memory_size();
 }
diff --git a/arch/x86/cpu/quark/dram.c b/arch/x86/cpu/quark/dram.c
index 2287dce..8b1ee2d 100644
--- a/arch/x86/cpu/quark/dram.c
+++ b/arch/x86/cpu/quark/dram.c
@@ -184,7 +184,7 @@
  * the relocation address, and how far U-Boot is moved by relocation are
  * set in the global data structure.
  */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	return gd->ram_size;
 }
diff --git a/arch/x86/cpu/slimbootloader/sdram.c b/arch/x86/cpu/slimbootloader/sdram.c
index c6f10e2..d748d5c 100644
--- a/arch/x86/cpu/slimbootloader/sdram.c
+++ b/arch/x86/cpu/slimbootloader/sdram.c
@@ -48,7 +48,7 @@
  * @total_size: The memory size that u-boot occupies
  * Return:    : The top available memory address lower than 4GB
  */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	struct sbl_memory_map_info *data;
 	int i;
diff --git a/arch/x86/cpu/tangier/sdram.c b/arch/x86/cpu/tangier/sdram.c
index afb0847..8a4b1c5 100644
--- a/arch/x86/cpu/tangier/sdram.c
+++ b/arch/x86/cpu/tangier/sdram.c
@@ -204,7 +204,7 @@
  * address, and how far U-Boot is moved by relocation are set in the global
  * data structure.
  */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	struct sfi_table_simple *sb;
 	struct sfi_mem_entry *mentry;
diff --git a/arch/x86/include/asm/mrc_common.h b/arch/x86/include/asm/mrc_common.h
index 3d7f00c..a7f260a 100644
--- a/arch/x86/include/asm/mrc_common.h
+++ b/arch/x86/include/asm/mrc_common.h
@@ -47,7 +47,7 @@
  * the relocation address, and how far U-Boot is moved by relocation are
  * set in the global data structure.
  */
-ulong mrc_common_board_get_usable_ram_top(ulong total_size);
+phys_size_t mrc_common_board_get_usable_ram_top(phys_size_t total_size);
 
 void mrc_common_dram_init_banksize(void);
 
diff --git a/arch/x86/include/asm/u-boot-x86.h b/arch/x86/include/asm/u-boot-x86.h
index a1655e1..4cf41e9 100644
--- a/arch/x86/include/asm/u-boot-x86.h
+++ b/arch/x86/include/asm/u-boot-x86.h
@@ -77,7 +77,7 @@
 void x86_enable_caches(void);
 void x86_disable_caches(void);
 int x86_init_cache(void);
-ulong board_get_usable_ram_top(ulong total_size);
+phys_size_t board_get_usable_ram_top(phys_size_t total_size);
 int default_print_cpuinfo(void);
 
 /* Set up a UART which can be used with printch(), printhex8(), etc. */
diff --git a/arch/x86/lib/fsp1/fsp_dram.c b/arch/x86/lib/fsp1/fsp_dram.c
index cfd9b9f..5825221 100644
--- a/arch/x86/lib/fsp1/fsp_dram.c
+++ b/arch/x86/lib/fsp1/fsp_dram.c
@@ -34,7 +34,7 @@
  * the relocation address, and how far U-Boot is moved by relocation are
  * set in the global data structure.
  */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	return fsp_get_usable_lowmem_top(gd->arch.hob_list);
 }
diff --git a/arch/x86/lib/fsp2/fsp_dram.c b/arch/x86/lib/fsp2/fsp_dram.c
index 42d3892..f9ea1ab 100644
--- a/arch/x86/lib/fsp2/fsp_dram.c
+++ b/arch/x86/lib/fsp2/fsp_dram.c
@@ -77,7 +77,7 @@
 	return 0;
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	if (!ll_boot_init())
 		return gd->ram_size;