[U-Boot] [PATCH] disk: part_efi: add support for the Alternate GPT

[Steve Rae <srae@broadcom.com>]

On 14-05-05 03:50 AM, Przemyslaw Marczak wrote:
> Hello Steve,
>
> On 04/30/2014 12:31 AM, Steve Rae wrote:
>> Check the Alternate GPT table if the Primary GPT table is invalid.
>>
>> Signed-off-by: Steve Rae <srae@broadcom.com>
>> ---
>>
>>   disk/part_efi.c | 20 ++++++++++++++++++--
>>   1 file changed, 18 insertions(+), 2 deletions(-)
>>
>> diff --git a/disk/part_efi.c b/disk/part_efi.c
>> index 216a292..ad899fa 100644
>> --- a/disk/part_efi.c
>> +++ b/disk/part_efi.c
>> @@ -93,7 +93,15 @@ void print_part_efi(block_dev_desc_t * dev_desc)
>>       if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
>>                gpt_head, &gpt_pte) != 1) {
>>           printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
>> -        return;
>> +        if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
>> +                 gpt_head, &gpt_pte) != 1) {
>> +            printf("%s: *** ERROR: Invalid Alternate GPT ***\n",
>> +                   __func__);
>> +            return;
>> +        } else {
>> +            printf("%s: ***        Using Alternate GPT ***\n",
>> +                   __func__);
>> +        }
>>       }
>>
>>       debug("%s: gpt-entry at %p\n", __func__, gpt_pte);
>> @@ -142,7 +150,15 @@ int get_partition_info_efi(block_dev_desc_t * 
>> dev_desc, int part,
>>       if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
>>               gpt_head, &gpt_pte) != 1) {
>>           printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
>> -        return -1;
>> +        if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
>> +                 gpt_head, &gpt_pte) != 1) {
>> +            printf("%s: *** ERROR: Invalid Alternate GPT ***\n",
>> +                   __func__);
>> +            return -1;
>> +        } else {
>> +            printf("%s: ***        Using Alternate GPT ***\n",
>> +                   __func__);
>> +        }
>>       }
>>
>>       if (part > le32_to_cpu(gpt_head->num_partition_entries) ||
>>
>
> This looks ok, we can still use u-boot filesystem commands after gpt 
> header block corruption, but the gpt is still...corrupted.
>
> Maybe we need additional gpt subcommand for restore gpt in case when 
> backup of gpt header is valid?
>
> Actually we have only "gpt write" command but it needs proper 
> environment variables. So I think that "gpt restore" is welcome.
>
> Thank you,
Agree -- maybe I can find time to work on a "gpt restore" in the near 
future....
Thanks, Steve