diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
index d115b25..47c0a4f 100644
--- a/arch/arm/mach-imx/imx8m/soc.c
+++ b/arch/arm/mach-imx/imx8m/soc.c
@@ -327,7 +327,7 @@
 	}
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	ulong top_addr;
 
diff --git a/arch/arm/mach-mvebu/arm64-common.c b/arch/arm/mach-mvebu/arm64-common.c
index 238edbe..63f6af5 100644
--- a/arch/arm/mach-mvebu/arm64-common.c
+++ b/arch/arm/mach-mvebu/arm64-common.c
@@ -30,7 +30,7 @@
  */
 #define USABLE_RAM_SIZE		0x80000000ULL
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	unsigned long top = CONFIG_SYS_SDRAM_BASE + min(gd->ram_size, USABLE_RAM_SIZE);
 
diff --git a/arch/arm/mach-rockchip/sdram.c b/arch/arm/mach-rockchip/sdram.c
index 705ec7b..12f1d7e 100644
--- a/arch/arm/mach-rockchip/sdram.c
+++ b/arch/arm/mach-rockchip/sdram.c
@@ -205,7 +205,7 @@
 	return 0;
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	unsigned long top = CONFIG_SYS_SDRAM_BASE + SDRAM_MAX_SIZE;
 
diff --git a/arch/arm/mach-stm32mp/dram_init.c b/arch/arm/mach-stm32mp/dram_init.c
index 920b99b..9346fa8 100644
--- a/arch/arm/mach-stm32mp/dram_init.c
+++ b/arch/arm/mach-stm32mp/dram_init.c
@@ -40,7 +40,7 @@
 	return 0;
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	phys_size_t size;
 	phys_addr_t reg;
diff --git a/arch/arm/mach-sunxi/board.c b/arch/arm/mach-sunxi/board.c
index 8f7c894..62bb40b 100644
--- a/arch/arm/mach-sunxi/board.c
+++ b/arch/arm/mach-sunxi/board.c
@@ -65,7 +65,7 @@
 };
 struct mm_region *mem_map = sunxi_mem_map;
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	/* Some devices (like the EMAC) have a 32-bit DMA limit. */
 	if (gd->ram_top > (1ULL << 32))
diff --git a/arch/arm/mach-tegra/board2.c b/arch/arm/mach-tegra/board2.c
index 8950e67..1994db0 100644
--- a/arch/arm/mach-tegra/board2.c
+++ b/arch/arm/mach-tegra/board2.c
@@ -401,7 +401,7 @@
  * This function is called before dram_init_banksize(), so we can't simply
  * return gd->bd->bi_dram[1].start + gd->bd->bi_dram[1].size.
  */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	ulong ram_top;
 
diff --git a/arch/mips/mach-jz47xx/jz4780/jz4780.c b/arch/mips/mach-jz47xx/jz4780/jz4780.c
index fefba12..a57ec78 100644
--- a/arch/mips/mach-jz47xx/jz4780/jz4780.c
+++ b/arch/mips/mach-jz47xx/jz4780/jz4780.c
@@ -76,7 +76,7 @@
 }
 #endif /* CONFIG_SPL_BUILD */
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	return CONFIG_SYS_SDRAM_BASE + (256 * 1024 * 1024);
 }
diff --git a/arch/mips/mach-octeon/dram.c b/arch/mips/mach-octeon/dram.c
index 4679260..9c5789b 100644
--- a/arch/mips/mach-octeon/dram.c
+++ b/arch/mips/mach-octeon/dram.c
@@ -77,7 +77,7 @@
 	return UBOOT_RAM_SIZE_MAX;
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	if (IS_ENABLED(CONFIG_RAM_OCTEON)) {
 		/* Map a maximum of 256MiB - return not size but address */
diff --git a/arch/riscv/cpu/fu540/dram.c b/arch/riscv/cpu/fu540/dram.c
index 1fdc783..44e11bd 100644
--- a/arch/riscv/cpu/fu540/dram.c
+++ b/arch/riscv/cpu/fu540/dram.c
@@ -21,7 +21,7 @@
 	return fdtdec_setup_memory_banksize();
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	/*
 	 * Ensure that we run from first 4GB so that all
diff --git a/arch/riscv/cpu/fu740/dram.c b/arch/riscv/cpu/fu740/dram.c
index 1dc77ef..d6d4a41 100644
--- a/arch/riscv/cpu/fu740/dram.c
+++ b/arch/riscv/cpu/fu740/dram.c
@@ -20,7 +20,7 @@
 	return fdtdec_setup_memory_banksize();
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 #ifdef CONFIG_64BIT
 	/*
diff --git a/arch/riscv/cpu/generic/dram.c b/arch/riscv/cpu/generic/dram.c
index 1fdc783..44e11bd 100644
--- a/arch/riscv/cpu/generic/dram.c
+++ b/arch/riscv/cpu/generic/dram.c
@@ -21,7 +21,7 @@
 	return fdtdec_setup_memory_banksize();
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	/*
 	 * Ensure that we run from first 4GB so that all
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;
diff --git a/board/broadcom/bcmns3/ns3.c b/board/broadcom/bcmns3/ns3.c
index 88036c1..26652e8 100644
--- a/board/broadcom/bcmns3/ns3.c
+++ b/board/broadcom/bcmns3/ns3.c
@@ -183,7 +183,7 @@
 }
 
 /* Limit RAM used by U-Boot to the DDR first bank End region */
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	return BCM_NS3_MEM_END;
 }
diff --git a/board/imgtec/boston/ddr.c b/board/imgtec/boston/ddr.c
index 182f79b..5b245cb 100644
--- a/board/imgtec/boston/ddr.c
+++ b/board/imgtec/boston/ddr.c
@@ -23,7 +23,7 @@
 	return 0;
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	DECLARE_GLOBAL_DATA_PTR;
 
diff --git a/board/menlo/m53menlo/m53menlo.c b/board/menlo/m53menlo/m53menlo.c
index 61ab384..4afc5aa 100644
--- a/board/menlo/m53menlo/m53menlo.c
+++ b/board/menlo/m53menlo/m53menlo.c
@@ -42,7 +42,7 @@
 
 static u32 mx53_dram_size[2];
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	/*
 	 * WARNING: We must override get_effective_memsize() function here
diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
index 17b8108..00afb35 100644
--- a/board/raspberrypi/rpi/rpi.c
+++ b/board/raspberrypi/rpi/rpi.c
@@ -335,7 +335,7 @@
 /*
  * Prevent relocation from stomping on a firmware provided FDT blob.
  */
-unsigned long board_get_usable_ram_top(unsigned long total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	if ((gd->ram_top - fw_dtb_pointer) > SZ_64M)
 		return gd->ram_top;
diff --git a/board/ti/am65x/evm.c b/board/ti/am65x/evm.c
index 8a0a506..34ec391 100644
--- a/board/ti/am65x/evm.c
+++ b/board/ti/am65x/evm.c
@@ -61,7 +61,7 @@
 	return 0;
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 #ifdef CONFIG_PHYS_64BIT
 	/* Limit RAM used by U-Boot to the DDR low region */
diff --git a/board/ti/j721e/evm.c b/board/ti/j721e/evm.c
index 5d09004..d6e431e 100644
--- a/board/ti/j721e/evm.c
+++ b/board/ti/j721e/evm.c
@@ -57,7 +57,7 @@
 	return 0;
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 #ifdef CONFIG_PHYS_64BIT
 	/* Limit RAM used by U-Boot to the DDR low region */
diff --git a/board/ti/j721s2/evm.c b/board/ti/j721s2/evm.c
index 3c75ecf..e09adc8 100644
--- a/board/ti/j721s2/evm.c
+++ b/board/ti/j721s2/evm.c
@@ -46,7 +46,7 @@
 	return 0;
 }
 
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 #ifdef CONFIG_PHYS_64BIT
 	/* Limit RAM used by U-Boot to the DDR low region */
diff --git a/board/xilinx/common/board.c b/board/xilinx/common/board.c
index e1f7104..391ce4d 100644
--- a/board/xilinx/common/board.c
+++ b/board/xilinx/common/board.c
@@ -631,7 +631,7 @@
 #endif
 
 #if defined(CONFIG_LMB)
-ulong board_get_usable_ram_top(ulong total_size)
+phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 	phys_size_t size;
 	phys_addr_t reg;
diff --git a/common/board_f.c b/common/board_f.c
index f92d7b9..aee3f56 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -305,7 +305,7 @@
 }
 
 /* Get the top of usable RAM */
-__weak ulong board_get_usable_ram_top(ulong total_size)
+__weak phys_size_t board_get_usable_ram_top(phys_size_t total_size)
 {
 #if defined(CONFIG_SYS_SDRAM_BASE) && CONFIG_SYS_SDRAM_BASE > 0
 	/*
diff --git a/include/init.h b/include/init.h
index 02bb4ce..50a8302 100644
--- a/include/init.h
+++ b/include/init.h
@@ -291,7 +291,7 @@
  *
  * @param total_size	Size of U-Boot (unused?)
  */
-ulong board_get_usable_ram_top(ulong total_size);
+phys_size_t board_get_usable_ram_top(phys_size_t total_size);
 
 int board_early_init_f(void);