[U-Boot] SAMA5D2 xplained SD/eMMC boot

[Yang, Wenyou]

Hi Marek,

> -----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
> 
> 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.

> 
> > 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


Best Regards,
Wenyou Yang