[PATCH 4/4] board: st: stm32mp25: support dynamic A/B bank bootup

[Dario Binacchi]

Enable automatic detection of the active A/B bank 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 stm32mp25 boards, add the following Kconfig
options to the stm32mp25_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 <dario.binacchi at amarulasolutions.com>

---

 board/st/stm32mp2/stm32mp2.c          | 25 +++++++++++++++++++++++++
 include/configs/stm32mp25_st_common.h | 15 +++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/board/st/stm32mp2/stm32mp2.c b/board/st/stm32mp2/stm32mp2.c
index 43bc583378e6..42df750eae9b 100644
--- a/board/st/stm32mp2/stm32mp2.c
+++ b/board/st/stm32mp2/stm32mp2.c
@@ -208,4 +208,29 @@ 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];
+
+	fwu_plat_get_bootidx(&boot_idx);
+
+	if (!fwu_mdata_get_image_guid(&boot_uuid, boot_type_guid,
+				      boot_idx) &&
+	    !fwu_mdata_get_image_guid(&root_uuid, root_type_guid,
+				      boot_idx)) {
+		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);
+	}
+
+	return 0;
+}
 #endif /* CONFIG_FWU_MULTI_BANK_UPDATE */
diff --git a/include/configs/stm32mp25_st_common.h b/include/configs/stm32mp25_st_common.h
index cb679eb1be22..0b0267ae99b0 100644
--- a/include/configs/stm32mp25_st_common.h
+++ b/include/configs/stm32mp25_st_common.h
@@ -8,7 +8,22 @@
 #ifndef __CONFIG_STM32MP25_ST_COMMON_H__
 #define __CONFIG_STM32MP25_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} ${devnum} -bootable devplist; "
+
+#define ST_STM32MP25_FWU_ENV \
+	"altbootcmd=${bootcmd}\0"
+#else
+#define ST_STM32MP25_FWU_ENV
+#endif
+
 #define STM32MP_BOARD_EXTRA_ENV \
+	ST_STM32MP25_FWU_ENV \
 	"usb_pgood_delay=2000\0" \
 	"console=ttySTM0\0"
 
-- 
2.43.0