efi: arm: Add an EFI app for arm64

Introduce an EFI app for arm64 and update the documentation.

Provide a value for LOAD_ADDR to avoid a link error.

Signed-off-by: Simon Glass <sjg@chromium.org>

Kconfig

@@ -551,6 +551,7 @@ config SYS_LOAD_ADDR
 	default 0x12000000 if ARCH_MX6 && !(MX6SL || MX6SLL  || MX6SX || MX6UL || MX6ULL)
 	default 0x80800000 if ARCH_MX7
 	default 0x90000000 if FSL_LSCH2 || FSL_LSCH3
+	default 0x02000000 if ARCH_EFI
 	default 0x0 if ARCH_SC5XX
 	help
 	  Address in memory to use as the default safe load address.

MAINTAINERS

@@ -1066,12 +1066,14 @@ M:	Simon Glass <sjg@chromium.org>
 M:	Heinrich Schuchardt <xypron.glpk@gmx.de>
 S:	Maintained
 W:	https://docs.u-boot.org/en/latest/develop/uefi/u-boot_on_efi.html
+F:	board/efi/efi-arm_app
 F:	board/efi/efi-x86_app
+F:	configs/efi-arm_app*
 F:	configs/efi-x86_app*
 F:	doc/develop/uefi/u-boot_on_efi.rst
 F:	drivers/block/efi-media-uclass.c
 F:	drivers/block/sb_efi_media.c
-F:	lib/efi/efi_app.c
+F:	lib/efi/
 F:	scripts/build-efi.py
 F:	test/dm/efi_media.c
 

arch/arm/dts/efi-arm_app.dts

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2015 Google, Inc
+ */
+
+/dts-v1/;
+
+/include/ "skeleton.dtsi"
+
+/ {
+	model = "EFI ARM Application";
+	compatible = "efi,arm-app";
+
+	chosen {
+		stdout-path = &serial;
+	};
+
+	serial: serial {
+		compatible = "efi,uart";
+	};
+
+	reset {
+		compatible = "efi,reset";
+		bootph-all;
+	};
+	efi-fb {
+		compatible = "efi-fb";
+		bootph-some-ram;
+	};
+
+};

board/efi/Kconfig

@@ -45,4 +45,27 @@ source "board/efi/efi-x86_payload/Kconfig"
 
 endif  # X86
 
+if ARM
+
+choice
+	prompt "Mainboard model"
+	optional
+
+config TARGET_EFI_ARM_APP64
+	bool "64-bit efi application"
+	select EFI_APP
+	select SYS_CUSTOM_LDSCRIPT
+	select ARM64
+	help
+	  This target is used for running U-Boot on top of EFI in 64-bit mode.
+	  In this case EFI does the early initialisation, and U-Boot
+	  takes over once the RAM, video and CPU are fully running.
+	  U-Boot is loaded as an application from EFI.
+
+endchoice
+
+source "board/efi/efi-arm_app/Kconfig"
+
+endif  # ARM
+
 endif  # ARCH_EFI

board/efi/efi-arm_app/Kconfig

@@ -0,0 +1,19 @@
+if EFI_APP
+
+config SYS_BOARD
+	default "efi-arm_app"
+
+config SYS_VENDOR
+	default "efi"
+
+config SYS_SOC
+	default "efi"
+
+config BOARD_SPECIFIC_OPTIONS # dummy
+	def_bool y
+	imply VIDEO_EFI
+
+config SYS_LDSCRIPT
+	default "arch/arm/lib/elf_aarch64_efi.lds"
+
+endif

board/efi/efi-arm_app/MAINTAINERS

@@ -0,0 +1,13 @@
+EFI-ARM_APP32 BOARD
+M:	Simon Glass <sjg@chromium.org>
+S:	Maintained
+F:	board/efi/Kconfig
+F:	board/efi/efi-arm_app/
+F:	configs/efi-arm_app32_defconfig
+
+EFI-ARM_APP64 BOARD
+M:	Simon Glass <sjg@chromium.org>
+S:	Maintained
+F:	board/efi/Kconfig
+F:	board/efi/efi-arm_app/
+F:	configs/efi-arm_app64_defconfig

board/efi/efi-arm_app/Makefile

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+
+obj-y	+= board.o

board/efi/efi-arm_app/board.c

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2015 Google, Inc
+ */
+
+#include <init.h>
+
+struct mm_region *mem_map;
+
+int print_cpuinfo(void)
+{
+	return 0;
+}
+
+int board_init(void)
+{
+	return 0;
+}

board/efi/efi-arm_app/efi-arm_app.env

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Environment file for ARM EFI app
+ *
+ * Copyright 2025, Simon Glass <simon.glass@canonical.com>
+ */
+
+/* common console settings */
+stdin=serial
+stdout=serial,vidconsole
+stderr=serial,vidconsole

configs/efi-arm_app64_defconfig

@@ -0,0 +1,51 @@
+CONFIG_ARM=y
+# CONFIG_ARM64_CRC32 is not set
+CONFIG_ARCH_EFI_ARM=y
+CONFIG_NR_DRAM_BANKS=8
+CONFIG_ENV_SIZE=0x1000
+CONFIG_DEFAULT_DEVICE_TREE="efi-arm_app"
+CONFIG_DEBUG_UART_BASE=0x0
+CONFIG_DEBUG_UART_CLOCK=0
+CONFIG_DEBUG_UART=y
+CONFIG_TARGET_EFI_ARM_APP64=y
+CONFIG_EFI=y
+CONFIG_EFI_APP_64BIT=y
+CONFIG_FIT=y
+# CONFIG_BOOTSTD is not set
+CONFIG_SHOW_BOOT_PROGRESS=y
+CONFIG_USE_BOOTARGS=y
+CONFIG_SYS_PBSIZE=532
+CONFIG_SYS_CONSOLE_INFO_QUIET=y
+CONFIG_LOG=y
+CONFIG_DISPLAY_BOARDINFO_LATE=y
+CONFIG_HUSH_PARSER=y
+CONFIG_CMD_BOOTZ=y
+CONFIG_CMD_MEMINFO=y
+CONFIG_CMD_MEMINFO_MAP=y
+CONFIG_CMD_DM=y
+CONFIG_CMD_PART=y
+CONFIG_CMD_DNS=y
+CONFIG_CMD_WGET=y
+CONFIG_CMD_CACHE=y
+CONFIG_CMD_TIME=y
+CONFIG_CMD_EXT2=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_CMD_FAT=y
+CONFIG_CMD_FS_GENERIC=y
+CONFIG_MAC_PARTITION=y
+CONFIG_ISO_PARTITION=y
+CONFIG_EFI_PARTITION=y
+CONFIG_OF_LIVE=y
+CONFIG_ENV_OVERWRITE=y
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_USE_BOOTFILE=y
+CONFIG_BOOTFILE="bzImage"
+CONFIG_REGMAP=y
+CONFIG_SYSCON=y
+CONFIG_EFI_NET=y
+CONFIG_DM_RNG=y
+CONFIG_SYSRESET=y
+CONFIG_VIDEO=y
+CONFIG_CONSOLE_SCROLL_LINES=5
+CONFIG_CMD_DHRYSTONE=y

doc/develop/uefi/u-boot_on_efi.rst

@@ -27,16 +27,17 @@ Running U-Boot on EFI is useful in several situations:
 
 Status
 ------
-Only x86 is supported at present. If you are using EFI on another architecture
-you may want to reconsider. However, much of the code is generic so could be
-ported.
+Only x86 and ARM64 are supported at present. If you are using EFI on another
+architecture you may want to reconsider. However, much of the code is generic so
+could be ported.
 
-U-Boot supports running as an EFI application for both 32- and 64-bit EFI.
+U-Boot supports running as an EFI application for both 32- and 64-bit EFI on
+x86, and for 64-bit on ARM.
 
-U-Boot supports building itself as a payload for either 32-bit or 64-bit EFI.
-U-Boot is packaged up and loaded in its entirety by EFI. Once started, U-Boot
-changes to 32-bit mode (currently) and takes over the machine. You can use
-devices, boot a kernel, etc.
+On x86, U-Boot supports building itself as a payload for either 32-bit or 64-bit
+EFI. U-Boot is packaged up and loaded in its entirety by EFI. Once started,
+U-Boot changes to 32-bit mode (currently) and takes over the machine. You can
+use devices, boot a kernel, etc.
 
 
 Build Instructions

lib/efi/Kconfig

@@ -17,7 +17,7 @@ choice
 
 config EFI_APP
 	bool "Support running as an EFI application"
-	depends on !ARM
+	depends on X86 || ARM
 	select CHARSET
 	help
 	  Build U-Boot as an application which can be started from EFI. This