[U-Boot] SAMA5D2 xplained SD/eMMC boot

[Marek Vasut]

On 04/20/2016 03:17 AM, Yang, Wenyou wrote:
> Hi Marek,
> 
>> -----Original Message-----
>> From: Marek Vasut [mailto:marex at denx.de]
>> Sent: 2016年4月20日 0:34
>> To: Yang, Wenyou <Wenyou.Yang at atmel.com>
>> Cc: u-boot at lists.denx.de
>> Subject: Re: SAMA5D2 xplained SD/eMMC boot
>>
>> On 04/19/2016 05:22 AM, Yang, Wenyou wrote:
>>> Hi Marek,
>>>
>>>> -----Original Message-----
>>>> From: Marek Vasut [mailto:marek.vasut at gmail.com]
>>>> Sent: 2016年4月18日 23:30
>>>> To: Yang, Wenyou <Wenyou.Yang at atmel.com>
>>>> Cc: u-boot at lists.denx.de
>>>> Subject: SAMA5D2 xplained SD/eMMC boot
>>>>
>>>> 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-at91
>>
>> 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 ?

> Thank you.
> 
>>
>>>> This is a result of hard-coding boot
>>>> device to
>>>> BOOT_DEVICE_MMC1 in arch/arm/mach-at91/spl.c spl_boot_device() I think.
>>>>
>>>> Is there any way to discern from which SDHCI the board booted to
>>>> continue loading u-boot.img from the correct one ? This would let us
>>>> implement
>>>> board_boot_order() and boot from correct SDHCI.
>>>>
>>>> --
>>>> Best regards,
>>>> Marek Vasut
>>>
>>>
>>> Best Regards,
>>> Wenyou Yang
>>>
>>
>>
>> --
>> Best regards,
>> Marek Vasut
> 
> 
> Best Regards,
> Wenyou Yang
> 


-- 
Best regards,
Marek Vasut