[U-Boot] u-boot for Snow problem

[Michal Suchanek]

Hello,

On 4 March 2015 at 00:46, Simon Glass <sjg at chromium.org> wrote:
> Hi Michal,
>
> On 2 March 2015 at 04:25, Michal Suchanek <hramrach at gmail.com> wrote:
>> Hello,
>>
>> On 18 February 2015 at 06:24, Michal Suchanek <hramrach at gmail.com> wrote:
>>> On 18 February 2015 at 03:27, Simon Glass <sjg at chromium.org> wrote:
>>>> Hi Michal,
>>>>
>>>> On 16 February 2015 at 04:41, Michal Suchanek <hramrach at gmail.com> wrote:
>>>>> On 13 February 2015 at 05:51, Simon Glass <sjg at chromium.org> wrote:
>>>>>> Hi Michal,
>>>>>>
>>>>>> On 11 February 2015 at 10:16, Michal Suchanek <hramrach at gmail.com> wrote:
>>>>>>>
>>>>>>> Hello,
>>>>>>>
>>>>>>> I changed the SYS_START to work around the bug in the manufacturer
>>>>>>> firmware, applied snow_defconfig, built u-boot.bin, packed it into
>>>>>>> kernel uimage, signed it, copied it to a kernel partition, bumped
>>>>>>> priority of the partition, and rebooted.
>>>>>>>
>>>>>>
>>>>>> Do you mean u-boot-dtb.bin? If not you won't get a device tree and it
>>>>>> won't work.
>>>>>
>>>>> No, u-boot.bin. With u-boot-dtb.bin I get a snow # prompt on the
>>>>> built-in LCD, and working keyboard.
>>>>
>>>> OK sounds like it is working, good! I wonder if we should have a page
>>>> on elinux.org?
>>
>> It is working to some extent.
>>
>> I managed to load kernel from the emmc which works fine but the kernel
>> cannot read the emmc after it boots because it does not properly parse
>> the partitioning scheme. This should be trivially fixable in the
>> kernel and might actually work if I updated my sources but rebasing
>> the extra patches required for Snow is not automatically handled.
>>
>> On the other hand, the linux kernel has no problem with the SDXC card
>> in the SD slot and can read it just fine. Unfortunately, u-boot
>> complains about EFI partition errors and won't load anything from the
>> card. I tried two different GPT partitioning tools on the card and
>> both say that the partition layout is fine and that I have the default
>> 128 entries.
>>
>> How can I tell why u-boot does not like my GPT label?
>
> You could debug it in U-Boot and see what is going wrong.
>

Apparently the problem is that the dw mmc controller fails and the
sectors are unreadable. U-boot sometimes reports timeout, sometimes
data error, and sometimes nothing because the result has already been
cached probably. And the reason the dw mmc controller fails is that
port 1 is disabled. Not using disabled controllers would probably
solve the problem.

Thanks

Michal