[U-Boot] SAMA5D2 xplained SD/eMMC boot

[Marek Vasut]

On 04/21/2016 04:46 AM, Yang, Wenyou wrote:
> Hi,

Hi!

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>>>>>>>> Hi!
>>>>>>>>
>>>>>>>> I've been playing around with latest mainline u-boot on sama5d2
>>>>>>>> xplained ultra. I noticed that if I want to boot the board from
>>>>>>>> SD card (SDHCI1), the board will indeed load the SPL from it, but
>>>>>>>> SPL will try to load u-boot.img from eMMC
>>>>>>>> (SDHCI0) and fail, as my eMMC is blank.
>>>>>>>
>>>>>>> Yes, there is some issue to load u-boot.img. I found there is
>>>>>>> something to do on
>>>>>> sdhci.c.
>>>>>>>
>>>>>>> You can try this branch, it should works.
>>>>>>>
>>>>>>> https://github.com/linux4sam/u-boot-at91/commits/u-boot-2016.03-at
>>>>>>> 91
>>>>>>
>>>>>> I am not interested in using non-mainline stuff. Do you have any
>>>>>> particular patch/commit which I can refer to ? I do not think this
>>>>>> has anything to do with sdhci.c driver at all, it has to do with
>>>>>> detecting the boot device from which SPL was started and loading
>>>>>> u-boot.img from the same boot device instead of always using SDHCI0.
>>>>>
>>>>> I will test the mainline code. I will let you know when I get something.
>>>>
>>>> OK.
>>>>
>>>> Does the SoC have any sort of register which lists the current boot device ?
>>>
>>> In this SoC, there is not register to list the current boot device.
>>
>> And thus, it is not possible to detect at runtime from which device the SoC booted
>> and thus load u-boot.img from the same device. Correct ?
> 
> Yes, 

Ha, thanks for confirming.

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Best regards,
Marek Vasut