[PATCH v2 1/1] spl: allow loading via partition type GUID

[Heinrich Schuchardt]

Some boards provide main U-Boot as a dedicated partition to SPL.
Currently we can define either a fixed partition number or an MBR
partition type to define which partition is to be used.

Partition numbers tend to conflict with established partitioning schemes
of Linux distros. MBR partitioning is more and more replaced by GPT
partitioning.

Allow defining a partition type GUID identifying the partition to load
main U-Boot from.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
v2:
	avoid if/endif in Kconfig
---
 common/spl/Kconfig   | 27 ++++++++++++++++++++++-----
 common/spl/spl_mmc.c | 13 +++++++++++++
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 3c2af453ab..9d12b48297 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -514,19 +514,36 @@ config SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
 	  used in raw mode
 
 config SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION_TYPE
-	bool "MMC raw mode: by partition type"
+	bool "MMC raw mode: by MBR partition type"
 	depends on DOS_PARTITION && SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION
 	help
-	  Use partition type for specifying U-Boot partition on MMC/SD in
+	  Use MBR partition type for specifying U-Boot partition on MMC/SD in
 	  raw mode. U-Boot will be loaded from the first partition of this
 	  type to be found.
 
 config SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION_TYPE
-	hex "Partition Type on the MMC to load U-Boot from"
+	hex "MBR Partition Type on the MMC to load U-Boot from"
 	depends on SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION_TYPE
 	help
-	  Partition Type on the MMC to load U-Boot from, when the MMC is being
-	  used in raw mode.
+	  MBR Partition Type on the MMC to load U-Boot from, when the MMC is
+	  being used in raw mode.
+
+config SYS_MMCSD_RAW_MODE_U_BOOT_USE_GPT_PARTITION_TYPE
+	bool "MMC raw mode: GPT by partition type"
+	depends on PARTITION_TYPE_GUID && SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION
+	help
+	  Use GPT partition type for specifying U-Boot partition on MMC/SD in
+	  raw mode. U-Boot will be loaded from the first partition of this
+	  type to be found.
+
+config SYS_MMCSD_RAW_MODE_U_BOOT_GPT_PARTITION_TYPE
+	string "GPT Partition Type on the MMC to load U-Boot from"
+	depends on SYS_MMCSD_RAW_MODE_U_BOOT_USE_GPT_PARTITION_TYPE
+	default d2f002f8-e4e7-4269-b8ac-3bb6fabeaff6
+	help
+	  GPT Partition Type on the MMC to load U-Boot from, when the MMC is
+	  being used in raw mode. The GUID must be lower case, low endian,
+	  and formatted like d2f002f8-e4e7-4269-b8ac-3bb6fabeaff6.
 
 config SUPPORT_EMMC_BOOT_OVERRIDE_PART_CONFIG
 	bool "Override eMMC EXT_CSC_PART_CONFIG by user defined partition"
diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c
index e4135b2048..69bf1d6e98 100644
--- a/common/spl/spl_mmc.c
+++ b/common/spl/spl_mmc.c
@@ -191,6 +191,19 @@ static int mmc_load_image_raw_partition(struct spl_image_info *spl_image,
 	struct disk_partition info;
 	int err;
 
+#ifdef CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_GPT_PARTITION_TYPE
+	for (int i = 1; i <= MAX_SEARCH_PARTITIONS; ++i) {
+		err = part_get_info(mmc_get_blk_desc(mmc), i, &info);
+		if (err)
+			continue;
+		if (!strncmp(info.type_guid,
+			     CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_GPT_PARTITION_TYPE,
+			     UUID_STR_LEN)) {
+			partition = i;
+			break;
+		}
+	}
+#endif
 #ifdef CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION_TYPE
 	int type_part;
 	/* Only support MBR so DOS_ENTRY_NUMBERS */
-- 
2.38.1