[PATCH 0/4] rockchip: Improve support for Bob chromebook and add support for Kevin

[Peter Robinson]

On Fri, Dec 3, 2021 at 8:13 PM Simon Glass <sjg at chromium.org> wrote:
>
> Hi Peter,
>
> On Fri, 3 Dec 2021 at 05:20, Peter Robinson <pbrobinson at gmail.com> wrote:
> >
> > On Fri, Dec 3, 2021 at 3:32 AM Simon Glass <sjg at chromium.org> wrote:
> > >
> > > Hi Peter,
> > >
> > > On Wed, 1 Dec 2021 at 07:23, Peter Robinson <pbrobinson at gmail.com> wrote:
> > > >
> > > > On Thu, Nov 25, 2021 at 5:39 PM Alper Nebi Yasak
> > > > <alpernebiyasak at gmail.com> wrote:
> > > > >
> > > > > I have recently started testing booting U-Boot from SPI on my gru-kevin
> > > > > (as opposed to chainloading it from vendor coreboot + depthcharge) and
> > > > > brought it to a better working state based on an initial support patch
> > > > > from Marty [1][2] and some follow-up work by Simon [3].
> > > > >
> > > > > I tried to keep them as the git author when I took things from their
> > > > > work, but squashing other changes into those and rewriting commit
> > > > > messages makes things a bit weird in my opinion, especially for keeping
> > > > > their signoff. Do tell me if there is a better way to that.
> > > > >
> > > > > As the Kevin and Bob boards are very similar. I assumed the config and
> > > > > devicetree changes will be appropriate for Bob as well, and applied them
> > > > > to it first. I do not have a Bob, so could not test on one myself, but
> > > > > Simon did test an earlier version of this and it appears to work [4].
> > > > >
> > > > > Other useful things for these boards:
> > > > > - Patch to fix a hang when usb controllers exit [5]
> > > > > - Series to support HS400ES mode as HS400 training fails [6]
> > > > > - Hack to skip eMMC reinitialization so it keeps working [7]
> > > >
> > > > Is there docs updates to be done in doc/chromium/ for this so people
> > > > know how to use it ?
> > >
> > > This is for bare-metal use though, so it isn't anything to do with
> > > Chromium at present.
> >
> > So are there docs for how do this? I didn't manage to find any,
> > although the docs I find can be a little over the place in U-Boot so
> > they may be there and I missed them, so either way docs would be fab.
>
> There are SPI instructions at doc/board/rockchip but they are pretty
> 'one way'. So you would need a way to get your old SPI-flash contents
> back when it doesn't work, because I don't think these platforms
> support SD boot. I use a 'servo' board and a Dediprog em100 SPI
> emulator. I know that kevin does not support CCD (Close-Case
> Debugging) so you cannot program the SPI flash that way...

I thought there was a different process for the chtomebooks than the
usual rockchip route. Do the rockchip chomebooks support writing to a
space in SPI and chainloading like some of the other arm chtomebooks
did (I think tegra/samsung but my memory fades there)? I think it
would be useful to document the rockchip chromebook options somewhere
so that people that are interested in using the U-Boot option have
some resources, we've had a few queries over the time around that.

Peter