[PATCH v5 01/16] partmap/gpt: Add grub_gpt_partition_get_uuid()

[Vitaly Kuzmichev]

This patch adds a function to provide partition PARTUUID on GPT
formatted disks by extracting 16 bytes GUID from corresponding GPT
entry and formatting it similarly to 'blkid' output.

Signed-off-by: Vitaly Kuzmichev <vitaly.kuzmichev@rtsoft.de>
---
 grub-core/partmap/gpt.c      | 36 ++++++++++++++++++++++++++++++++++++
 include/grub/gpt_partition.h |  2 ++
 2 files changed, 38 insertions(+)

diff --git a/grub-core/partmap/gpt.c b/grub-core/partmap/gpt.c
index 877ceefc3..b43f46987 100644
--- a/grub-core/partmap/gpt.c
+++ b/grub-core/partmap/gpt.c
@@ -22,6 +22,7 @@
 #include <grub/mm.h>
 #include <grub/partition.h>
 #include <grub/dl.h>
+#include <grub/charset.h>
 #include <grub/msdos_partition.h>
 #include <grub/gpt_partition.h>
 #include <grub/i18n.h>
@@ -49,6 +50,41 @@ static struct grub_partition_map grub_gpt_partition_map;
 
 
 
+char *
+grub_gpt_partition_get_uuid (grub_device_t dev)
+{
+  struct grub_gpt_partentry gptdata;
+  grub_disk_t disk;
+  grub_partition_t pt;
+  grub_guid_t *guid;
+  char *part_uuid = NULL;
+
+  if (dev && dev->disk && dev->disk->partition && 
dev->disk->partition->partmap)
+    {
+      pt = dev->disk->partition;
+      if (grub_strcmp (pt->partmap->name, "gpt") == 0)
+       {
+         disk = grub_disk_open (dev->disk->name);
+         if (disk && grub_disk_read (disk, pt->offset, pt->index,
+                                     sizeof (gptdata), &gptdata) == 0)
+           {
+             guid = &gptdata.guid;
+             guid->data1 = grub_le_to_cpu32 (guid->data1);
+             guid->data2 = grub_le_to_cpu16 (guid->data2);
+             guid->data3 = grub_le_to_cpu16 (guid->data3);
+             part_uuid = grub_xasprintf ("%pG", guid);
+           }
+         if (!part_uuid)
+           grub_error_push ();
+         grub_disk_close (disk);
+         if (!part_uuid)
+           grub_error_pop ();
+       }
+    }
+
+  return part_uuid;
+}
+
 grub_err_t
 grub_gpt_partition_map_iterate (grub_disk_t disk,
                                grub_partition_iterate_hook_t hook,
diff --git a/include/grub/gpt_partition.h b/include/grub/gpt_partition.h
index 020e71920..e52834ac2 100644
--- a/include/grub/gpt_partition.h
+++ b/include/grub/gpt_partition.h
@@ -74,5 +74,7 @@ grub_gpt_partition_map_iterate (grub_disk_t disk,
                                grub_partition_iterate_hook_t hook,
                                void *hook_data);
 
+char *
+grub_gpt_partition_get_uuid (grub_device_t dev);
 
 #endif /* ! GRUB_GPT_PARTITION_HEADER */
-- 
2.34.1