Extended Addressing Mode

[Benjamin Herrenschmidt]

On Wed, 2008-10-22 at 08:08 -0500, Kumar Gala wrote:
> > We are developing a board based on Freescale 8641D which can get
> 4GB  
> > of ram. So I need 4GB+IOs (~1GB) of physical addressing space.
> > My plan is to put a part of this ram above of 4GB to keep accesses  
> > to the IOs below the 4GB limit. It means non-contiguous ram  
> > addressing and XAEN features to be working.

Why would you put the IOs below the 4G point ? It's actually easier
to have the IOs up above, like a lot of 4xx do.

Cheers,
Ben.