[U-Boot] [PATCH 7/7] tegra: seaboard: disable SPI, move environment to eMMC

[Simon Glass]

Hi Stephen,

On Thu, May 31, 2012 at 5:00 PM, Stephen Warren <swarren at wwwdotorg.org>wrote:

> On 05/31/2012 05:39 PM, Simon Glass wrote:
> > Hi Stephen,
> >
> > On Thu, May 24, 2012 at 2:38 PM, Stephen Warren <swarren at wwwdotorg.org
> > <mailto:swarren at wwwdotorg.org>> wrote:
> >
> >     From: Stephen Warren <swarren at nvidia.com <mailto:swarren at nvidia.com
> >>
> >
> >
> > Acked-by: Simon Glass <sjg at chromium.org <mailto:sjg at chromium.org>>
> >
> > But a question - what happens if we have a partition table and
> > filesystems on the eMMC - i.e. if we are not actually booting from eMMC?
>
> The eMMC is divided into:
>
> * Boot block 0, 512K
> * Boot block 1, 512K
> * Main area, the rest
>
> This patch stores the environment at the end of boot block 1.
>

OK, I suppose this depends on the device, but these are the devices that
are soldered down on these boards. Bear in mind we might use the fdt to
select between board variants, but ok.


>
> The Linux kernel sees each of those 3 areas as separate block devices
> (and indeed the 2 boot blocks are read-only by default and require sysfs
> writes to enable writing). As such, any partition table etc. would be
> confined to the main area. So, there should be no conflict between PT/FS
> and saved environment.
>
> SD cards don't have these separate areas, and it may even be optional on
> eMMC. Still, the Seaboard/Springbank eMMC has these separate blocks.
>

Thanks for the explanation, that sounds fine.

Regards,
Simon