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

Alper Nebi Yasak alpernebiyasak at gmail.com
Tue Dec 7 23:21:59 CET 2021

On 03/12/2021 23:13, Simon Glass wrote:
> 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:
>>> 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
>>>>> [...]
>>>> Is there docs updates to be done in doc/chromium/ for this so people
>>>> know how to use it ?

I tried to document how I'm using this at my GitHub wiki [1]. I want to
eventually rework that for U-Boot docs, but I feel I need to explore
chromium things a bit more, and want to solve the major problems with
these boards before doing that exploration.

[1] https://github.com/alpernebbi/u-boot/wiki

>>> 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...

The doc/board/rockchip instructions are slightly outdated in that they
don't mention u-boot.rom, it's enough just to flash that whichever way
possible. There's also the additional prerequisite of disabling
write-protection, which I tried to explain a bit in that wiki as well.

I can usually flash things from U-Boot/Linux, but when I flash a bad
build I do have to use my CH341A + 1.8V adapter to recover from it.

I don't know if booting from an SD card is outright impossible on these
boards, but current config doesn't even have the devices enabled in SPL,
and I couldn't get it to work with my naive blind attempts.

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