[coreboot] 4 GB RAM failure on DBM690T target (690G/SB600)

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Wed Jan 21 02:50:35 CET 2009

On 20.01.2009 17:13, Rudolf Marek wrote:
>> I'm not totally sure the ACPI code is hard coded to 1 GB. The default
>> values in the ACPI code code correspond to 1 GB and there is some code
>> which will calculate BIOS memory location from TOM and TOM2. I could not
>> find any place where TOM and TOM2 are updated, 
> its in acpi-k8.c in amd directory. Its in ssdt table.

Thanks. Unfortunately, the situation is more complicated on DBM690T.
TOM (the top below 4 GB) is stored twice, once in the SSDT (modified
automatically) and once in the DSDT (unmodified). TOM2 is only stored in
the DSDT (unmodified). The (correct) value of TOM in the SSDT is ignored
and the (incorrect) values of TOM/TOM2 in the DSDT are used.



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