[U-Boot] [PATCH 7/7] sunxi: Add environment settings to make extlinux.conf booting work

[Dennis Gilmore]

On Fri, 01 Aug 2014 14:22:40 -0600
Stephen Warren <swarren at wwwdotorg.org> wrote:

> On 08/01/2014 02:05 PM, Dennis Gilmore wrote:
> > On Fri, 01 Aug 2014 12:57:31 -0600
> > Stephen Warren <swarren at wwwdotorg.org> wrote:
> >
> >> On 08/01/2014 01:46 AM, Hans de Goede wrote:
> >>> Automatic booting using an extlinux.conf file requires various
> >>> environment variables to be set.
> >>
> >> Acked-by: Stephen Warren <swarren at nvidia.com>
> >>
> >> I'd personally be tempted to set fdt_high=0xffffffff,
> >> initrd_high=0xffffffff to stop U-Boot copying the DT/initrd from
> >> the load location to some other location under 256M, but that's
> >> just an optimization and entirely optional.
> >
> > There has been quite a few times where using 0xffffff has caused
> > issues.
> 
> What kind of issues?
> 
> At least for Tegra, I've carefully chosen the values for the various 
> load addresses so that there won't be issues. (Without that I can
> easily see the potential for issues.) I've seen far more repeated
> problems when U-Boot moves the DT/initrd around than than when it
> didn't (none in that case). Besides, it's completely redundant and
> unnecessary work if the blobs are already loaded at sane addresses,
> which they are on Tegra at least.

Mostly to do with the decompressed kernel overwriting the initrd or dtb
resulting in machines that would hang on boot. it came up quite a few
times earlier this year on both imx and omap.

Dennis