[U-Boot] [PATCH 2/5] nand: sunxi: Add support for booting from internal NAND memory

[Ian Campbell <ijc@hellion.org.uk>]

On Tue, 2015-05-05 at 11:19 +0200, Daniel Kochma?ski wrote:
> (sorry for resending, used wrong mail here - not sure how mailing list
> will handle that).
> 
> Ian Campbell writes:
> 
> > On Wed, 2015-04-29 at 17:02 +0200, Daniel Kochma?ski wrote:
> >> diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
> >> index 88e3358..1a30684 100644
> >> --- a/board/sunxi/Kconfig
> >> +++ b/board/sunxi/Kconfig
> >> @@ -239,6 +239,18 @@ config MMC_SUNXI_SLOT_EXTRA
> >>  	slot or emmc on mmc1 - mmc3. Setting this to 1, 2 or 3 will enable
> >>  	support for this.
> >>  
> >> +config SPL_NAND_SUPPORT
> >> +	bool "SPL/NAND mode support"
> >> +	depends on SPL
> >> +	default n
> >> +	---help---
> >> +	  This enables support for booting from NAND internal
> >> +	  memory. U-Boot SPL doesn't detect where is it load from,
> >> +	  therefore this option is needed to properly load image from
> >> +	  flash. Option also disables MMC functionality on U-Boot due to
> >> +	  initialization errors encountered, when both controllers are
> >> +	  enabled.
> >
> > Is this last bit a bug in the s/w or a hardware thing? Does this mean
> > that MMC is not available in the main u-boot image too when NAND support
> > is enabled?
> >
> 
> I'm not sure what is a reason, but controller can't initialize MMC when
> SPL is loaded. MMC works in main u-boot allowing to boot from it and
> perform any other option (rescan, part, info, etc.). It is only SPL
> relevant.

How strange! Hans, do you have any ideas about why this might be the
case? Is there some overlap between MMC and NAND? I can't think what...