[LinuxBIOS] AMD Geode LX VSA and VSMs

[Jordan Crouse]

On 04/05/07 02:09 +0200, Peter Stuge wrote:
> On Thu, May 03, 2007 at 09:39:27AM -0600, Jordan Crouse wrote:
> > > Would it make sense to move parts or all of the VSM code into the
> > > operating system?
> > 
> > Thats what OFW does for OLPC - and its fraught with danger.  Case
> > in point?  A few days ago, the amount of video memory was doubled
> > in OFW, to 16MB.  But since the PCI spoofing happens in the kernel,
> > it didn't get the message that the video memory changed, and the
> > PCI BAR was still sized to 8MB, and X goes boom.
> 
> Oh, no, that's not what I meant.
> 
> I meant that the code in the kernel would be completely native to the
> hardware. No spoofing.

So what would handle the several dozen MSRs needed to set up routing -
some of which are for essential devices that don't have drivers?   And
we would have to invent a new bus just for Geode devices (some of which
share code with other entities - amd74xxx IDE for example), because without
PCI, you wouldn't be able to match vendor/device IDs, or control the
devices, or assign I/O or memory resources in virtual space, at least 
not easily.

So basically it would take the Geode from a pretty well supported platform
to one that would be completely custom and on the fringe, and certainly
not suitable for the mainstream kernel.  I think the SMM handler is a small
price to pay. :)

Jordan