[coreboot] [PATCH] AMD MMCONF Support

Arne Georg Gleditsch arne.gleditsch at numascale.com
Wed Sep 8 17:00:18 CEST 2010

Myles Watson <mylesgw at gmail.com> writes:
> I'm confused why you wouldn't add the resource from the northbridge
> code.  Is there a reason to have it be a mainboard resource?

Not really, but there's no existing infrastructure for having
add_northbridge_resources be called except by way of
add_mainboard_resources.  As far as I can tell.  I think this may
warrant changing, but preferrably as a separate step.

> +	bool
> +	default y
> You could use select for MMCONF_SUPPORT.  I think it should be
> selected in the northbridge or in the mainboard, but not both.

MMCONF_SUPPORT is selected in the northbridge, MMCONF_SUPPORT_DEFAULT is
selected in the mainboard config to actually activate the functionality.
This was the way I read the existing code, perhaps this two-level
approach is not be required?  Either way, I think you want to select
this on a mainboard-by-mainboard basis, at least initially.  There is a
potential for breakage, like the one we experienced with the nvidia

> Instead of adding the reserved area directly to the coreboot tables,
> you should add it before resource allocation and let the rest happen
> automatically.

I'm sorry, I'm not at all familiar with the resource allocation
framework.  I tried to model this on the corresponding code for relevant
Intel mainboards.  How would you change it, precisely?


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