disk: efi: ignore 'IGNOREME' GPT header found on cros eMMCs

Some ChromeOS devices (atleast veyron speedy) have the first 8MiB of
the eMMC write protected and equipped with a dummy 'IGNOREME' GPT
header - instead of spewing error messages about it, just silently
try the backup GPT.

Note: this does not touch the gpt cmd writing/verifying functions,
those will still complain.

Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
This commit is contained in:
Urja Rannikko 2019-04-11 20:27:51 +00:00 committed by Kever Yang
parent 20c568cae6
commit 0557d46b63
2 changed files with 23 additions and 7 deletions

View file

@ -908,7 +908,7 @@ static int is_pmbr_valid(legacy_mbr * mbr)
* gpt is a GPT header ptr, filled on return.
* ptes is a PTEs ptr, filled on return.
*
* Description: returns 1 if valid, 0 on error.
* Description: returns 1 if valid, 0 on error, 2 if ignored header
* If valid, returns pointers to PTEs.
*/
static int is_gpt_valid(struct blk_desc *dev_desc, u64 lba,
@ -934,6 +934,12 @@ static int is_gpt_valid(struct blk_desc *dev_desc, u64 lba,
return 0;
}
/* Invalid but nothing to yell about. */
if (le64_to_cpu(pgpt_head->signature) == GPT_HEADER_CHROMEOS_IGNORE) {
debug("ChromeOS 'IGNOREME' GPT header found and ignored\n");
return 2;
}
if (validate_gpt_header(pgpt_head, (lbaint_t)lba, dev_desc->lba))
return 0;
@ -977,16 +983,24 @@ static int is_gpt_valid(struct blk_desc *dev_desc, u64 lba,
static int find_valid_gpt(struct blk_desc *dev_desc, gpt_header *gpt_head,
gpt_entry **pgpt_pte)
{
if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
gpt_head, pgpt_pte) != 1) {
printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
gpt_head, pgpt_pte) != 1) {
int r;
r = is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA, gpt_head,
pgpt_pte);
if (r != 1) {
if (r != 2)
printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
if (is_gpt_valid(dev_desc, (dev_desc->lba - 1), gpt_head,
pgpt_pte) != 1) {
printf("%s: *** ERROR: Invalid Backup GPT ***\n",
__func__);
return 0;
}
printf("%s: *** Using Backup GPT ***\n", __func__);
if (r != 2)
printf("%s: *** Using Backup GPT ***\n",
__func__);
}
return 1;
}

View file

@ -25,6 +25,8 @@
#define EFI_PMBR_OSTYPE_EFI_GPT 0xEE
#define GPT_HEADER_SIGNATURE_UBOOT 0x5452415020494645ULL
#define GPT_HEADER_CHROMEOS_IGNORE 0x454d45524f4e4749ULL // 'IGNOREME'
#define GPT_HEADER_REVISION_V1 0x00010000
#define GPT_PRIMARY_PARTITION_TABLE_LBA 1ULL
#define GPT_ENTRY_NUMBERS CONFIG_EFI_PARTITION_ENTRIES_NUMBERS