[coreboot] Porting to RS780/SB700 board

Marc Jones marcj303 at gmail.com
Mon May 3 06:01:26 CEST 2010


On Sun, May 2, 2010 at 9:24 PM, Ed Swierk <eswierk at aristanetworks.com> wrote:
> On Sun, May 2, 2010 at 3:45 PM, Rudolf Marek <r.marek at assembler.cz> wrote:
>> I re-checked and it was OK, we do have an early function with same name which
>> takes bytes parameters (mtrr-early.c). So this is not the case. I investigated
>> MTRRs bit more.
>
> I noticed that too. Perhaps we should rename the early version to
> something like early_set_var_mtrr() to avoid confusion?
>

That would be good.

>> The RAM init on AMD does not use the varmtrr0 and varmtrr1 the reason is that it
>> thinks the first is used for 0-RAMBASE second for ROM caching.
>>
>> I also changed the XIP MTRR setup to cache whole ROM with the MTRR. I think it
>> is OK to do it this way...
>>
>> After the code goes to the post_cache_as_ram.c it sets up an mtrr for the
>> coreboot_ram as 0-RAMTOP. Maybe we can go with a big mtrr 0-TOM and create UCs
>> for VGA....
>
> Would we also need to carve out an uncached space for any MMIO BARs
> that are used during early setup?
>

TOM will have the hole already handled and additional memory would be hoisted.

Marc

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