[coreboot] Lenovo Thinkpad X201: cannot boot encrypted Debian w/Coreboot & GRUB2

[Sam Kuper]

On 23/03/2017, Arthur Heymans <arthur at aheymans.xyz> wrote:
>> I tried again, this time with SeaBIOS instead of GRUB2 as the primary
>> payload, and with CoreInfo as a secondary payload. As above, I
>> selected "Use native graphics initialization" under "Devices" within
>> `make nconfig`. (See attached .config .)
>>
>> The result was the same as above: the backlight came on, but there was
>> nothing displayed on the screen.
>>
> I would not be too surprised if native graphic init is invalid for
> Nehalem, since looks like a rough copy of ivy/sandy bridge...
>
> (A quick look at the code tells me computing PLL divisors is too rough to
> be right in all cases. When it is too much out range for a display a lit
> up black screen is typically all you get...)

Interesting. Thank you very much for looking into this.

I wonder if this is a regression? The wiki states, "VGA Option ROM
(optional): you need it if you want graphics in SeaBIOS but most
payloads (e.g. GRUB2) work just fine without it (text mode or
corebootfb mode)".

That statement resulted from the following edits:

GNUtoo in 2013:
https://www.coreboot.org/index.php?title=Board:lenovo/x201&diff=prev&oldid=11609

GNUtoo in 2013:
https://www.coreboot.org/index.php?title=Board:lenovo/x201&diff=prev&oldid=11614

phcoder in 2013:
https://www.coreboot.org/index.php?title=Board:lenovo/x201&diff=prev&oldid=12266

phcoder in 2014:
https://www.coreboot.org/index.php?title=Board:lenovo/x201&diff=next&oldid=13360

Kl3 in 2015: https://www.coreboot.org/index.php?title=Board:lenovo/x201&diff=next&oldid=16692

So, it would seem that during 2013-2015, native graphics init became
operational within Coreboot for the X201. So, if it was working then,
but isn't working now, that would seem to indicate a regression. I
have CC'd the people who I understand are the authors of those
commits. I would be grateful if anyone can shed light on this :)



> One option is to extract the option rom from vendor bios and use that
> for init.

True. I was hoping to avoid this, but you are right that I should give
it a go (at least, to rule out whether any other issues are causing
the blank screen).


> Another is to fix up that native graphic init.

That is beyond my present skill level, I fear ;)


> Last option is hook up libgfxinit, an alternative Intel display init
> code written in ada/spark, which might set up display correctly...

Nice. I will look into that when I get a chance. It might take me a
while. I haven't built an Ada toolchain before. Would be great if it
works, though!


>> Is there anyone on the list who has Coreboot working on an X201 who
>> would be willing to share their .config file, so that I might see how
>> they succeeded where I am failing?

This question still stands, especially for those I have CC'd, who seem
to have been successful with Coreboot and native graphics
initialization on the X201 :)