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

Stephen Warren swarren at wwwdotorg.org
Thu Mar 14 05:36:38 CET 2013


On 03/13/2013 08:51 PM, Sonic Zhang wrote:
> 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.

Windows didn't give me that option. Do I need a smaller SD card to get
that option? Can you simply upload a compressed disk image or a hex dump
of the first sector instead?



More information about the U-Boot mailing list