efi: add helper to get the GPT partition UUID for a device

Signed-off-by: Michael Olbrich <[email protected]> Signed-off-by: Sascha Hauer <[email protected]>
ndreys · Jul 27, 2015 · be2edd9 · be2edd9
1 parent 55da0cf
commit be2edd9
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Showing 2 changed files with 31 additions and 0 deletions.
diff --git a/common/efi-devicepath.c b/common/efi-devicepath.c
@@ -1383,3 +1383,33 @@ u8 device_path_to_type(struct efi_device_path *dev_path)
 
 	return device_path_type(dev_path);
 }
+
+char *device_path_to_partuuid(struct efi_device_path *dev_path)
+{
+	struct efi_device_path *dev_path_node;
+	struct harddrive_device_path *hd;
+	char *str = NULL;;
+
+	dev_path = unpack_device_path(dev_path);
+
+	for (dev_path_node = dev_path; !is_device_path_end(dev_path_node);
+	     dev_path_node = next_device_path_node(dev_path_node)) {
+
+		if (device_path_type(dev_path_node) != MEDIA_DEVICE_PATH)
+			continue;
+
+		if (dev_path_node->sub_type != MEDIA_HARDDRIVE_DP)
+			continue;
+
+		hd = (struct harddrive_device_path *)dev_path_node;
+
+		if (hd->signature_type != SIGNATURE_TYPE_GUID)
+			continue;
+
+		str = xasprintf("%pUl", (efi_guid_t *)&(hd->signature[0]));
+		break;
+	}
+
+	return str;
+}
+
diff --git a/include/efi.h b/include/efi.h
@@ -624,6 +624,7 @@ static inline int efi_compare_guid(efi_guid_t *a, efi_guid_t *b)
 
 char *device_path_to_str(struct efi_device_path *dev_path);
 u8 device_path_to_type(struct efi_device_path *dev_path);
+char *device_path_to_partuuid(struct efi_device_path *dev_path);
 
 const char *efi_guid_string(efi_guid_t *g);