[U-Boot] [PATCH v1] DOS_PBR block type is also valid dos block type.

Sonic Zhang sonic.adi at gmail.com
Thu Mar 14 03:51:45 CET 2013


Hi Stephen,

On Thu, Mar 14, 2013 at 1:11 AM, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 03/11/2013 08:59 PM, Sonic Zhang wrote:
>> Hi Stephen,
>>
>> On Tue, Mar 12, 2013 at 1:28 AM, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>> On 03/11/2013 03:56 AM, sonic.adi at gmail.com wrote:
>>>> From: Sonic Zhang <sonic.zhang at analog.com>
>>>>
>>>> - Should return 0 for both DOS_MBR and DOS_PBR block types in test_part_dos().
>>>
>>> What problem does this solve?
>>>
>>> I don't believe this change is correct. The purpose of test_part_dos()
>>> is to determine whether a block device contains an MS-DOS partition table.
>>>
>>> Such a partition table is present in an MBR, but not a PBR. A PBR
>>> contains a *FAT file-system, and does not include a partition table.
>>
>> The SD card formated by windows 7 into one FAT partition can't be
>> initialized correct in u-boot function init_part() after you reuse the
>> function test_block_type() in function test_part_dos(). So, files on
>> that partition can't be displayed when running command "fatls mmc 0".
>>
>> The only difference in your change is to mark dos partition with flag
>> DOS_PBR invalid.
>
> Hmmm. I obtained an SD card that had been formatted in Windows 7
> (inserted SD card, right-clicked on it in Explorer, selected Format,
> selected default FAT32 options), and could not reproduce this issue.
>
> Can you give more explicit instructions on how to reproduce this
> problem? Perhaps a hexdump of the first sector would also help, or
> uploading a heavily compressed image of the SD card that I can dd onto mine.
>
> Also, what branch/commit of U-Boot are you using?

You should create a FAT partition on your SD card other than FAT32.

Regards,

Sonic


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