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

Sonic Zhang sonic.adi at gmail.com
Thu Mar 14 08:31:44 CET 2013


Hi Stephen,

On Thu, Mar 14, 2013 at 12:36 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
> 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?
>

Yes, you can use a small SD card such as 256M, 512M. Or create a small
partition on your large SD card.


Regards,

Sonic


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