In message <20010128144630.Y24228@dr-evil.shagadelic.org> Jason R
Thorpe writes: 
[[ Problem with machines that can only dma into memory on a pci bridge
   chip ]]
: I suspect the only systems on which this is really an issue are those
: which have a PCI bus that's designed to deal with exactly one device.

NetBSD/arc might support the Deskstation Tyne.  The Tyne is a EISA
machine that has lots of slots (6 or 8 I think), but can only DMA into
a fixed SRAM area.  I've not looked at that, but wanted to give
another example.  The SRAM area is on the order of 64k iirc.  I don't
actually have one, I have its ancestor the Desktation rPC44.

Warner