[coreboot] v3 stage2 running from flash

ron minnich rminnich at gmail.com
Wed Jan 7 06:45:49 CET 2009

On Tue, Jan 6, 2009 at 11:47 AM, Carl-Daniel Hailfinger
<c-d.hailfinger.devel.2006 at gmx.net> wrote:

> As long as CAR is active, we don't want the cacheable area (CAR+ROM) to
> be bigger than the cache to prevent cache evictions of CAR contents.
> That means we can cache the boot block and maybe initram. In that
> situation, having initram directly before the boot block is a huge speed
> benefit.
> Once CAR is no longer active, we immediately want to mark the whole ROM
> and RAM as cacheable to speed up decompression.

Yes. And you want to have those MTRRs in a state that they'll be
correct even if the OS you boot doesn't touch them.

One logical place is at the end of initram. I'd like to get the
discussion to some agreement on where this code should be, and then we
can worry about writing the code. Maybe I am missing part of the
discussion but we seem to be going in circles at times :-)

As for the CAR+ROM area caching, no argument; what I think we're
saying is we may need the ability to control where a LAR file ends up
in ROM so we can limit the cacheable area. Does that make sense?


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