[coreboot] [RFC] Re-thinking the stages

ron minnich rminnich at gmail.com
Fri Apr 6 22:38:56 CEST 2012

On Fri, Apr 6, 2012 at 11:12 AM, Marc Jones <marcj303 at gmail.com> wrote:

>> 3. Microcode updates
>> The "tiny" bootblock doesn't seem like the correct place for microcode
>> updates.
> Does microcode have to be this early? Before CAR?

Yes. Some history. We started out doing microcode updates in linux.
Then it moved to the end of the ram stage. Then the start. Then it
turned out it had to happen before CAR.

So be careful! Sure, it may not make sense, but hardware often does
not. This is an example of a seemingly sensible change, that would
work on many platforms, and destroy others. This is a really tricky

>> One such a nice app would be zmodem download of raminit.
> This is an interesting thought, but really a debug/development
> feature.

We even talked about this in v3. But it never got done, seems there is
no interest.

> I am not convinced of the value of earlier serial console. It adds
> complexity where things should be simple. I hesitate to continue
> moving more code before CAR. We have had a long standing goal to
> reduce code before CAR.

CAR is fragile! I agree. It should be reduced as much as possible.

You may want to look at what we did in v3, it has some similarities to
your ideas. And, we dropped it :-)


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