On 03/12/2021 23:13, Simon Glass wrote:
On Fri, 3 Dec 2021 at 05:20, Peter Robinson pbrobinson@gmail.com wrote:
On Fri, Dec 3, 2021 at 3:32 AM Simon Glass sjg@chromium.org wrote:
On Wed, 1 Dec 2021 at 07:23, Peter Robinson pbrobinson@gmail.com wrote:
On Thu, Nov 25, 2021 at 5:39 PM Alper Nebi Yasak alpernebiyasak@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The doc/board/rockchip instructions are slightly outdated in that they don't mention u-boot.rom, it's enough just to flash that whichever way possible.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.