[PATCH 6/8] env: mmc: select GPT env partition by type guid

[Patrick Delaunay]

Since commit c0364ce1c695 ("doc/README.gpt: define partition type GUID for
U-Boot environment"), a specific type GUID can be used to indicate
the U-Boot environment partition on the device with GPT partition table.

This patch uses this type GUID to found the env partition as fallback
when the partition name property "u-boot,mmc-env-partition" is not present
in config node or if the indicated partition name is not found.

The mmc_offset_try_partition() function is reused, it selects the first
partition with the correct type GUID when the parameter 'str' is NULL.

Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
---

 env/mmc.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/env/mmc.c b/env/mmc.c
index 1894b6483220..bd7d51e6b633 100644
--- a/env/mmc.c
+++ b/env/mmc.c
@@ -74,8 +74,18 @@ static inline int mmc_offset_try_partition(const char *str, int copy, s64 *val)
 		if (ret < 0)
 			return ret;
 
-		if (!strncmp((const char *)info.name, str, sizeof(info.name)))
+		if (str && !strncmp((const char *)info.name, str, sizeof(info.name)))
 			break;
+#ifdef CONFIG_PARTITION_TYPE_GUID
+		if (!str) {
+			const efi_guid_t env_guid = PARTITION_U_BOOT_ENVIRONMENT;
+			efi_guid_t type_guid;
+
+			uuid_str_to_bin(info.type_guid, type_guid.b, UUID_STR_FORMAT_GUID);
+			if (!memcmp(&env_guid, &type_guid, sizeof(efi_guid_t)))
+				break;
+		}
+#endif
 	}
 
 	/* round up to info.blksz */
@@ -112,6 +122,13 @@ static inline s64 mmc_offset(int copy)
 			return val;
 	}
 
+	/* try the GPT partition with "U-Boot ENV" TYPE GUID */
+	if (IS_ENABLED(CONFIG_PARTITION_TYPE_GUID)) {
+		err = mmc_offset_try_partition(NULL, copy, &val);
+		if (!err)
+			return val;
+	}
+
 	defvalue = ENV_MMC_OFFSET;
 	propname = dt_prop.offset;
 
-- 
2.25.1