DIMM relocation on Tyan S2885

[Eric W. Biederman]

ron minnich <rminnich at lanl.gov> writes:

> On Sun, 11 Jan 2004, Matt Harvey wrote:
> 
> > So the question to the panel is: Will LinuxBIOS solve this problem for
> > me? The task this machine was purchased for really does require as much
> > RAM as possible.
> 
> well, I think we can solve it for you. I have one of these boards, if you 
> want to do the homework on how to do it I'll try to do it.

There are a couple of ways to implement this.  If you have less than
4GB in one of the cpus you can put that cpu below 4G and the rest about.

Alternatively you can not enable dimm row interleaving, and create
a hole in a single cpus memory map, but putting the base address for
all but the first dimm rom about 4GB.  This looses a little performance
though.

And on the extreme side I think it would be possible to place all
of memory about 4GB and to use the GART to get a little of it to
appear below 4GB.  If this works there are still some very interesting
issues that crop up when the OS takes over the GART, and reprograms
it.

Eric