[coreboot] T420s white screen

[Jason Andryuk]

Hi,

I've been running coreboot on my T420s for a year or so.  It was
working fine, but today it isn't booting.  When I hit the power
button, I just get a white screen.  Well, maybe grey and not white,
but not the black background with white text like I usually see for my
seabios payload.

I tried blindly booting and getting past the disk encryption, but I
didn't see the laptop DHCP to the router.  I might have botched that
though...

Once or twice earlier I had this white screen.  In those cases, I just
powered off and tried again and it worked.

Has anyone seen something like this before?

One thought is the RTC battery may be old and have lost its charge.
But would a dead battery exhibit this behavior?

Thanks,
Jason