[coreboot] Bricked Lenovo T60

Gerd Hoffmann kraxel at redhat.com
Fri Jun 21 23:44:24 CEST 2013

On 06/21/13 18:26, ron minnich wrote:
> the question about fallback is 'when do I tell the machine that the
> normal boot succeeded'? At LANL, we learned the best place: as LATE in
> the boot process as possible, long after LInux is up. You want to be
> sure, if you set 'booted ok', that it is LINUX that booted ok, not
> just coreboot. That's a key piece.

I think at least on a developer machine you never ever want do that
automatically ...

After wading through the source code, looking especially at
do_normal_boot() I think I figured how things are supposed to work.
There are two bits and one counter in the cmos boot byte.

One bit says "always boot normal mode".
The other bit says "increase counter, when it is smaller than
MAX_REBOOT_CNT boot normal, otherwise switch to fallback".

So with this I should be able to make coreboot boot normal once, and on
the next boot switch to fallback no matter what.  So all I have to do in
case normal doesn't boot up is to power-cycle the machine ...


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