[coreboot] SeaBIOS WinXP install

[Carl-Daniel Hailfinger]

On 01.09.2009 22:15, Rudolf Marek wrote:
>> On 01.09.2009 15:00, Arnaud Maye wrote:
>>> I've been implementing the ACPI for the ep80579 and so far it is not
>>> going very well. Linux refuses to boot unless I use acpi=off or
>>> acpi=ht as boot parameters. acpi=ht seems to display my ACPI ioports
>>> in proc/ioports as expected ( the ioports addresses are all mapped to
>>> the ACPI BAR ). Without to disable acpi the kernel complains that the
>>> 0xE0000000 range is not a reserved  range and the MMCONF is not
>>> supported and then hangs.
>
> It should not hang. The complain is only about e820 map is not
> reserved. I made recently a small patch for this for K8M890. Simply
> the problem seems elsewhere to me.

But if MMCONF is not seen as active, the kernel might allocate something
else in that area. If the ACPI code uses MMCONF for PCI accesses, this
means the ACPI code will write/read with undefined side effects.
Besides that, if you forgot to (re)activate MMCONFIG inside coreboot,
you might see similar effects. I was fighting with RS690 code which
enabled MMCONF, used it for a few accesses, then disabled it again, but
the ACPI code tried to use MMCONF anyway. Effect were SATA problems/hangs.
Besides that, enabling MMCONF in the chipset may break some classic PCI
accesses. For example, if I enable MMCONF in the chipset and if the
kernel doesn't accept it due to missing reservation, my network card
fails because it uses extended config space for storing the MAC and
other stuff. When MMCONFIG in the chipset is disabled, it works, so
there must be some further interaction (maybe enabling MMCONFIG breaks
other access methods to extended config space).

Regards,
Carl-Daniel

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