Check the correct length of the GPT header signature
The length of the signature is 8 bytes. We've been checking 9
bytes instead, pretty much forever. All the tests have passed
because although the signature we're looking for is an 8-byte
string followed by a '\0', the next field in the header contains
the revision number 0x00010000, so the 9th byte is always zero.
We should follow the spec, though.
BUG=none
BRANCH=none
TEST=make runtests
Change-Id: I7cc6370250fa36a193f4a9fa5bc0099aea465618
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/247331
Reviewed-by: Randall Spangler <rspangler@chromium.org>
diff --git a/firmware/include/gpt.h b/firmware/include/gpt.h
index fa53739..15918a7 100644
--- a/firmware/include/gpt.h
+++ b/firmware/include/gpt.h
@@ -2,19 +2,22 @@
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
- * Defines EFI related structure. See more details in EFI 2.3 spec.
+ * Defines UEFI related structure. See more details in the UEFI spec.
*
- * To download EFI standard, please visit UEFI homepage:
+ * To download UEFI standard, please visit UEFI homepage:
* http://www.uefi.org/
*/
#ifndef VBOOT_REFERENCE_CGPTLIB_GPT_H_
#define VBOOT_REFERENCE_CGPTLIB_GPT_H_
#include <stdint.h>
-#define GPT_HEADER_SIGNATURE "EFI PART"
-#define GPT_HEADER_SIGNATURE2 "CHROMEOS"
-#define GPT_HEADER_SIGNATURE_SIZE sizeof(GPT_HEADER_SIGNATURE)
+/* From the specification */
+#define GPT_HEADER_SIGNATURE_SIZE 8
#define GPT_HEADER_REVISION 0x00010000
+#define GPT_HEADER_SIGNATURE "EFI PART"
+
+/* From https://chromium-review.googlesource.com/31264 */
+#define GPT_HEADER_SIGNATURE2 "CHROMEOS"
/*
* The first 3 numbers should be stored in network-endian format according to
@@ -43,7 +46,7 @@
#define UUID_NODE_LEN 6
#define GUID_SIZE 16
-/* GUID definition. Defined in appendix A of EFI standard. */
+/* GUID definition. Defined in appendix A of UEFI standard. */
typedef struct {
union {
struct {
@@ -63,12 +66,12 @@
/*
* GPT header defines how many partitions exist on a drive and sectors managed.
* For every drive device, there are 2 headers, primary and secondary. Most of
- * fields are duplicated except my_lba and entries_lba.
+ * the fields are duplicates except my_lba and entries_lba.
*
- * You may find more details in chapter 5 of EFI standard.
+ * You may find more details in chapter 5 of the UEFI standard.
*/
typedef struct {
- char signature[8];
+ char signature[GPT_HEADER_SIGNATURE_SIZE];
uint32_t revision;
uint32_t size;
uint32_t header_crc32;
@@ -91,7 +94,7 @@
* GPT partition entry defines the starting and ending LBAs of a partition. It
* also contains the unique GUID, type, and attribute bits.
*
- * You may find more details in chapter 5 of EFI standard.
+ * You may find more details in chapter 5 of the UEFI standard.
*/
typedef struct {
Guid type;
