[U-Boot] SAMA5D2 xplained SD/eMMC boot

[Marek Vasut]

On 04/21/2016 04:30 AM, Yang, Wenyou wrote:
> Hi Marek,

Hi!

>> -----Original Message-----
>> From: Marek Vasut [mailto:marex at denx.de]
>> Sent: 2016年4月20日 17:37
>> To: Yang, Wenyou <Wenyou.Yang at atmel.com>
>> Cc: u-boot at lists.denx.de
>> Subject: Re: SAMA5D2 xplained SD/eMMC boot

Can you fix your mailer so it doesn't insert this crap into each and
every message ? Pretty please ?

>> 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 ?
> 
> 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 ?

You should add such register, it's a few lines of HDL ...

[...]
Best regards,
Marek Vasut