board: st: stm32mp15: support dynamic A/B bank bootup

Following commit 4300f9f4c5d7 ("board: st: stm32mp25: support dynamic
A/B bank bootup"), this patch enables automatic detection of the active
A/B bank on STM32MP15 platforms by retrieving partition GUIDs from FWU
metadata.

This ensures the system correctly identifies the bootable partitions
even in multi-bank scenarios, falling back to a standard bootable flag
scan if the UUIDs are missing.

To enable A/B bank bootup on STM32MP15 boards, add the following Kconfig
options to the  stm32mp15[_basic]_defconfig:

 CONFIG_FWU_MULTI_BANK_UPDATE=y
 CONFIG_FWU_MDATA=y
 CONFIG_FWU_NUM_BANKS=2
 CONFIG_FWU_NUM_IMAGES_PER_BANK=3
 CONFIG_CMD_FWU_METADATA=y
 CONFIG_FWU_MDATA_V2=y

Signed-off-by: Dario Binacchi <[email protected]>
Reviewed-by: Patrice Chotard <[email protected]>

2 files changed, 48 insertions, 0 deletions

diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index 88ede4e3910..8164a62e9a3 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -857,4 +857,37 @@ void fwu_plat_get_bootidx(uint *boot_idx)
 	*boot_idx = (readl(TAMP_FWU_BOOT_INFO_REG) >>
 		    TAMP_FWU_BOOT_IDX_OFFSET) & TAMP_FWU_BOOT_IDX_MASK;
 }
+
+int fwu_platform_hook(struct udevice *dev, struct fwu_data *data)
+{
+	uint boot_idx;
+	efi_guid_t boot_uuid, root_uuid;
+	const efi_guid_t boot_type_guid = PARTITION_XBOOTLDR;
+	const efi_guid_t root_type_guid =
+		PARTITION_LINUX_FILE_SYSTEM_DATA_GUID;
+	char uuidbuf[UUID_STR_LEN + 1];
+	int retb, retr;
+
+	fwu_plat_get_bootidx(&boot_idx);
+
+	retb = fwu_mdata_get_image_guid(&boot_uuid, &boot_type_guid, boot_idx);
+	retr = fwu_mdata_get_image_guid(&root_uuid, &root_type_guid, boot_idx);
+
+	if (!retb && !retr) {
+		uuid_bin_to_str(boot_uuid.b, uuidbuf, UUID_STR_FORMAT_GUID);
+		env_set("boot_partuuid", uuidbuf);
+
+		uuid_bin_to_str(root_uuid.b, uuidbuf, UUID_STR_FORMAT_GUID);
+		env_set("root_partuuid", uuidbuf);
+	} else if (!retb && retr) {
+		log_warning("%s: found boot GUID but missing root GUID (%d)\n",
+			    __func__, retr);
+	} else if (!retr && retb) {
+		log_warning("%s: found root GUID but missing boot GUID (%d)\n",
+			    __func__, retb);
+	}
+
+	return 0;
+}
 #endif /* CONFIG_FWU_MULTI_BANK_UPDATE */
+
diff --git a/include/configs/stm32mp15_st_common.h b/include/configs/stm32mp15_st_common.h
index 60838cb0e3f..7727e583fc7 100644
--- a/include/configs/stm32mp15_st_common.h
+++ b/include/configs/stm32mp15_st_common.h
@@ -8,7 +8,22 @@
 #ifndef __CONFIG_STM32MP15_ST_COMMON_H__
 #define __CONFIG_STM32MP15_ST_COMMON_H__
 
+#ifdef CONFIG_FWU_MULTI_BANK_UPDATE
+#define SCAN_DEV_FOR_BOOT_PARTS \
+	"setenv devplist; " \
+	"env exists boot_partuuid && " \
+		"part number ${devtype} ${devnum} ${boot_partuuid} devplist; " \
+	"env exists devplist || " \
+		"part list ${devtype} ${devnum} -bootable devplist; "
+
+#define ST_STM32MP15_FWU_ENV \
+	"altbootcmd=${bootcmd}\0"
+#else
+#define ST_STM32MP15_FWU_ENV
+#endif
+
 #define STM32MP_BOARD_EXTRA_ENV \
+	ST_STM32MP15_FWU_ENV \
 	"usb_pgood_delay=2000\0" \
 	"console=ttySTM0\0" \
 	"splashimage=" __stringify(CONFIG_SYS_LOAD_ADDR) "\0" \