disk: part_efi: parse and store partition UUID

Each EFI partition table entry contains a UUID. Extend U-Boot's struct
disk_partition to be able to store this information, and modify
get_partition_info_efi() to fill it in.

The implementation of uuid_string() was derived from the Linux kernel,
tag v3.6-rc4 file lib/vsprintf.c function uuid_string().

Signed-off-by: Stephen Warren <swarren@nvidia.com>

disk/part.c

@@ -391,6 +391,11 @@ int get_partition_info(block_dev_desc_t *dev_desc, int part
 	defined(CONFIG_MMC) || \
 	defined(CONFIG_SYSTEMACE)
 
+#ifdef CONFIG_PARTITION_UUIDS
+	/* The common case is no UUID support */
+	info->uuid[0] = 0;
+#endif
+
 	switch (dev_desc->part_type) {
 #ifdef CONFIG_MAC_PARTITION
 	case PART_TYPE_MAC:

disk/part_efi.c

@@ -154,6 +154,28 @@ void print_part_efi(block_dev_desc_t * dev_desc)
 	return;
 }
 
+#ifdef CONFIG_PARTITION_UUIDS
+static void uuid_string(unsigned char *uuid, char *str)
+{
+	static const u8 le[16] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11,
+				  12, 13, 14, 15};
+	int i;
+
+	for (i = 0; i < 16; i++) {
+		sprintf(str, "%02x", uuid[le[i]]);
+		str += 2;
+		switch (i) {
+		case 3:
+		case 5:
+		case 7:
+		case 9:
+			*str++ = '-';
+			break;
+		}
+	}
+}
+#endif
+
 int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
 				disk_partition_t * info)
 {
@@ -190,6 +212,9 @@ int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
 	sprintf((char *)info->name, "%s",
 			print_efiname(&gpt_pte[part - 1]));
 	sprintf((char *)info->type, "U-Boot");
+#ifdef CONFIG_PARTITION_UUIDS
+	uuid_string(gpt_pte[part - 1].unique_partition_guid.b, info->uuid);
+#endif
 
 	debug("%s: start 0x%lX, size 0x%lX, name %s", __func__,
 		info->start, info->size, info->name);

include/part.h

@@ -94,6 +94,9 @@ typedef struct disk_partition {
 	uchar	name[32];	/* partition name			*/
 	uchar	type[32];	/* string type description		*/
 	int	bootable;	/* Active/Bootable flag is set		*/
+#ifdef CONFIG_PARTITION_UUIDS
+	char	uuid[37];	/* filesystem UUID as string, if exists	*/
+#endif
 } disk_partition_t;
 
 /* Misc _get_dev functions */