[coreboot] v3 CAR/ROM area collision on C7 and Core2Duo

Stefan Reinauer stepan at coresystems.de
Fri Nov 21 22:48:14 CET 2008

Carl-Daniel Hailfinger wrote:
> On 21.11.2008 21:34, Stefan Reinauer wrote:
>> On 21.11.2008, at 16:47, Carl-Daniel Hailfinger
>> <c-d.hailfinger.devel.2006 at gmx.net> wrote:
>>> Hi,
>>> in v2 we enable full ROM decoding before initram. For VIA C7 and Intel
>>> Core 2 Duo, that means the CAR area is inside the mapped ROM contents.
>> That observation is wrong for the intel core case. CAR lives 1MiB
>> below the rom there. So no problems arise.
> Core 2 Duo CAR lives at 0xFFEF0000 with a size of 32 kiB in v3.
> Core 2 Duo CAR lives at 0xFFDF8000 with a size of 32 kiB in v2 for the
> Kontron board.
Non of the Intel stuff in v3 even compiles, so don't worry about that
too much.

In v2, the CAR lives 1M below the ROM. If you change the ROM size, you
have to change the CAR BASE too. The code can use a little brush-up
there, but since we never had to use flash chips larger than 8MBit it
does not really matter.

> How variable is the location where we can have CAR in the Core 2 Duo? Is
> anything in the top 16 MiB allowed?
It needs to live 1MB below the flash part.

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