[U-Boot] [PATCH 1/3] disk: part_efi: parse and store partition UUID

[Stephen Warren]

From: Stephen Warren <swarren at nvidia.com>

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 stolen from the Linux kernel.

Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
Note: I made this field part of struct disk_partition, and wrote a generic
command to retrieve it, rather than adding an EFI-/GPT-specific command,
since I imagine the kernel's PARTUUID support could be extended to support
e.g. NT disk signatures, or other partition types, in the future.

 disk/part.c     |    3 +++
 disk/part_efi.c |   21 +++++++++++++++++++++
 include/part.h  |    1 +
 3 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/disk/part.c b/disk/part.c
index 76f3939..266d77e 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -294,6 +294,9 @@ void init_part (block_dev_desc_t * dev_desc)
 int get_partition_info (block_dev_desc_t *dev_desc, int part
 					, disk_partition_t *info)
 {
+	/* The common case is no UUID support */
+	info->uuid[0] = 0;
+
 	switch (dev_desc->part_type) {
 #ifdef CONFIG_MAC_PARTITION
 	case PART_TYPE_MAC:
diff --git a/disk/part_efi.c b/disk/part_efi.c
index 02927a0..199c054 100644
--- a/disk/part_efi.c
+++ b/disk/part_efi.c
@@ -154,6 +154,26 @@ void print_part_efi(block_dev_desc_t * dev_desc)
 	return;
 }
 
+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;
+		}
+	}
+}
+
 int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
 				disk_partition_t * info)
 {
@@ -183,6 +203,7 @@ 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");
+	uuid_string(gpt_pte[part - 1].unique_partition_guid.b, info->uuid);
 
 	debug("%s: start 0x%lX, size 0x%lX, name %s", __func__,
 		info->start, info->size, info->name);
diff --git a/include/part.h b/include/part.h
index e1478f4..52002f5 100644
--- a/include/part.h
+++ b/include/part.h
@@ -93,6 +93,7 @@ typedef struct disk_partition {
 	ulong	blksz;		/* block size in bytes			*/
 	uchar	name[32];	/* partition name			*/
 	uchar	type[32];	/* string type description		*/
+	char	uuid[37];	/* filesystem UUID as string, if exists	*/
 } disk_partition_t;
 
 /* Misc _get_dev functions */
-- 
1.7.0.4