Re: PCI mapping on large memory 32-bit machines

[William Lee Irwin III]

On Mon, May 19, 2003 at 02:15:23PM -0400, Timothy Miller wrote:
> On x86 with PAE and 4 gigs of RAM or more, where do memory-mapped I/O 
> devices get mapped (in the physical address space)?  Most PCI devices 
> can't handle 64-bit addresses.  Can PC chipsets physically remap some of 
> the RAM to above 4 gig?  Or do you just lose that much RAM?  If both RAM 
> and some I/O device are mapped to the same location, isn't there a conflict?

AFAIK most (if not all) of that lands below 4GB in extant chipsets/BIOS's.

Remapping above 4GB is possible but various things would probably barf.

-- wli