[coreboot] patch: add romfs to V2

Stefan Reinauer stepan at coresystems.de
Tue Mar 31 13:15:45 CEST 2009

On 31.03.2009 12:52 Uhr, Carl-Daniel Hailfinger wrote:
> I'm very sad to hear this. Sure, I've seen that v3 didn't improve at the
> rate it used to. But although I've been active in coreboot for 3 years:
> - I still do not understand the v2 build system.
> - I still do not understand the v2 device model.
> - I still do not understand the v2 Config.lb/Option.lb system.
> - I still do not understand the v2 fallback/normal/failover model.
> - I still do not understand the v2 design.
> - I still do not understand how v2 CAR and normal code interact.
We are all fighting with "smart conceptions" in version 2. But, I also
believe the reason we're not getting anywhere with v3 is that we refused
to get a decent understanding of what happens in v2. Starting out with a
clean room implementation like v3 helps to grasp many of the issues. Now
it is time for a "lessons learned".

> Every time I work on v2, I feel utterly incompetent. I just try to hack
> on it unintelligibly in the hope it doesn't explode in my face again and
> again.
Which is exactly why we started to improve v2.
> Every time I work on v3, I feel I understand everything. Working on it
> is a pleasure and tracking down bugs is rather easy because of the clear
> structure.
Except for the idiosyncratic implementation of some features, v2 is very
similar to v3. Don't let the few rough parts in v2 delude you into
thinking v3 were something completely different. Yes, v3 is simpler. And
yes, a lot of that is due to the fact that v3 lacks a lot of
functionality that we have in v2. A bike is more comfortable than a car,
if you have to carry it. Things change as soon as it's supposed to carry

> Now if we can make v2 use the v3 device model, DTS, config system, build
> system, stage design, LAR, CAR, startup code, global variables, struct
> device and printk buffer, v2 will become bearable. But then v2 will
> essentially be transformed into what v3 is now with additional ports.
I still think DTS isn't all that helpful, and a lot more complex than
what we have in v2 without any additional gain. For the rest, I agree.
We developed a lot of fine features in our experimental tree, and it's
about time we port those over so that people can actually use them.

> Bringing v3 concepts, but not code to v2 removes all implementation
> experience we have with those concepts. 
Why is that? We don't suddenly become oblivious, will we?

> If we already built and
> reinvented the wheel multiple times and the last one works rather well,
> rebuilding and partly reinventing it again feels really futile.
We have a pretty large stock pile of tires around here, but now it's
getting spring, and we want to mount a new set of tires. :-)


coresystems GmbH • Brahmsstr. 16 • D-79104 Freiburg i. Br.
      Tel.: +49 761 7668825 • Fax: +49 761 7664613
Email: info at coresystems.dehttp://www.coresystems.de/
Registergericht: Amtsgericht Freiburg • HRB 7656
Geschäftsführer: Stefan Reinauer • Ust-IdNr.: DE245674866

More information about the coreboot mailing list