[PATCH] arm: meson: add support for EFI capsule updates

[Ferass El Hafidi]

Previously, few Amlogic devices supported EFI capsule updates.
Generally only the Libre Computer ones with SPI flash supported it,
thanks to board-specific code.

This commit commonises capsule update support across supported
Amlogic boards.  Similar to Qualcomm's support for it, the dfu string
and firmware name is automatically generated at runtime depending on
which device we are booted from.  Right now this supports flashing to
the eMMC/SD and SPI flash.

As usual, the capsule UUID is automatically generated.  You can get it
by enabling CONFIG_CMD_EFIDEBUG and running:

	=> efidebug capsule esrt
	========================================
	ESRT: fw_resource_count=1
	ESRT: fw_resource_count_max=1
	ESRT: fw_resource_version=1
	[entry 0]==============================
	ESRT: fw_class=796180D4-AAB2-50F1-B16A-53DFF9CA89B2
	ESRT: fw_type=unknown
	ESRT: fw_version=0
	ESRT: lowest_supported_fw_version=0
	ESRT: capsule_flags=0
	ESRT: last_attempt_version=0
	ESRT: last_attempt_status=success
	========================================

Signed-off-by: Ferass El Hafidi <funderscore at postmarketos.org>
---
Currently EFI capsule updates are only supported on the following
Amlogic-based boards:

 - Libre Computer AML-S805X-AC
 - Libre Computer AML-A311D-CC
 - Libre Computer AML-S905D3-CC

This is done with board-specific configuration in board/libre-computer/.

With this patch, EFI capsule updates can now work on most of the other
Amlogic boards supported by u-boot, such as the Libre Computer
AML-S905X-CC, without the need for board-specific configuration
beforehand.
---
 arch/arm/include/asm/arch-meson/boot.h |  2 ++
 arch/arm/mach-meson/Makefile           |  2 +-
 arch/arm/mach-meson/board-common.c     |  3 ++
 arch/arm/mach-meson/capsule.c          | 59 ++++++++++++++++++++++++++++++++++
 4 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/arch-meson/boot.h b/arch/arm/include/asm/arch-meson/boot.h
index a11dfde719e3e48e10bcb1f6b1b84eb8586ca9e7..e66b45983fe2f5d81f83642c01502a72773213b2 100644
--- a/arch/arm/include/asm/arch-meson/boot.h
+++ b/arch/arm/include/asm/arch-meson/boot.h
@@ -21,6 +21,8 @@ int meson_get_boot_device(void);
 
 int meson_get_soc_rev(char *buff, size_t buff_len);
 
+void meson_setup_capsule(void);
+
 /**
  * meson_get_socinfo - retrieve cpu_id of the Amlogic SoC
  *
diff --git a/arch/arm/mach-meson/Makefile b/arch/arm/mach-meson/Makefile
index 535b0878b9105e7a83729bea65fa4cd70cd4beac..640921e2b8e9b4777f0b212991edea26de2987d4 100644
--- a/arch/arm/mach-meson/Makefile
+++ b/arch/arm/mach-meson/Makefile
@@ -2,7 +2,7 @@
 #
 # Copyright (c) 2016 Beniamino Galvani <b.galvani at gmail.com>
 
-obj-y += board-common.o sm.o board-info.o
+obj-y += board-common.o sm.o board-info.o capsule.o
 obj-$(CONFIG_MESON_GX) += board-gx.o
 obj-$(CONFIG_MESON_AXG) += board-axg.o
 obj-$(CONFIG_MESON_G12A) += board-g12a.o
diff --git a/arch/arm/mach-meson/board-common.c b/arch/arm/mach-meson/board-common.c
index 39774c43049a40ed11578086603717571bedd23b..df9f576e7d2a1ce77b9a98259de4c3abf87784ed 100644
--- a/arch/arm/mach-meson/board-common.c
+++ b/arch/arm/mach-meson/board-common.c
@@ -145,6 +145,9 @@ int board_late_init(void)
 {
 	meson_set_boot_source();
 
+	/* Generate dfu_string for EFI capsule updates */
+	meson_setup_capsule();
+
 	return meson_board_late_init();
 }
 
diff --git a/arch/arm/mach-meson/capsule.c b/arch/arm/mach-meson/capsule.c
new file mode 100644
index 0000000000000000000000000000000000000000..a798f8a3e8c3a8807720af4ef89ccfc20f22f2f8
--- /dev/null
+++ b/arch/arm/mach-meson/capsule.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2025, Ferass El Hafidi <funderscore at postmarketos.org>
+ */
+
+#include <dm.h>
+#include <asm/arch/boot.h>
+#include <efi_loader.h>
+#include <mmc.h>
+
+/*
+ * To be able to support multiple devices and flash to the correct one we need
+ * to automatically generate the dfu_string and fw_name to match the device we
+ * are booted from.  This is done by meson_setup_capsule() which is then called
+ * in board_late_init().  Right now we support EFI capsule updates on SPI flash,
+ * eMMC and SD cards.
+ */
+struct efi_fw_image fw_images[] = {
+	{
+		.image_index = 1,
+	},
+};
+
+struct efi_capsule_update_info update_info = {
+	.dfu_string = NULL, /* to be set in meson_capsule_setup */
+	.num_images = ARRAY_SIZE(fw_images),
+	.images = fw_images,
+};
+
+/*
+ * TODO: Support usecase e.g. FIT image on eMMC + SPL on SD.
+ */
+void meson_setup_capsule(void)
+{
+	static char dfu_string[32] = { 0 };
+	int mmc_devnum = 0; /* mmc0 => SD card */
+	static uint32_t max_size = 0x2000; /* 4 MB */
+	uint32_t offset = 0x1; /* offset for flashing to eMMC/SD */
+	int boot_device = meson_get_boot_device();
+
+	switch (boot_device) {
+	case BOOT_DEVICE_EMMC:
+		mmc_devnum = 1; /* mmc1 is always eMMC */
+	case BOOT_DEVICE_SD:
+		snprintf(dfu_string, 32, "mmc %d=u-boot.bin raw %d %d", mmc_devnum, offset, max_size);
+		fw_images[0].fw_name = u"U_BOOT_MESON_MMC";
+		break;
+	case BOOT_DEVICE_SPI:
+		/* We assume there's only one SPI flash */
+		fw_images[0].fw_name = u"U_BOOT_MESON_SPI";
+		snprintf(dfu_string, 32, "sf 0:0=u-boot.bin raw 0 %d", max_size);
+		break;
+	default:
+		debug("Boot device %d unsupported\n", boot_device);
+	}
+	debug("EFI Capsule DFU string: %s", dfu_string);
+
+	update_info.dfu_string = dfu_string;
+}

---
base-commit: 072264c4b3406aee50dad08355588577a547ab48
change-id: 20251007-meson-capsule-a19539e0a54e

Best regards,
-- 
Ferass El Hafidi <funderscore at postmarketos.org>