Subject: Re: PCI I/O address allocation
To: Lennart Augustsson <>
From: Chris G. Demetriou <>
List: tech-kern
Date: 11/25/1998 10:08:16
Lennart Augustsson <> writes:
> Sorry, I was just babbling without checking.  There are 6 BARs, but
> that doesn't change the fact that the SonicVibes card wants
> two additional I/O regions which are programmed at addresses 0x40 and 
> 0x48 in confuguration space.
> So the basic problem remains.

Ahh, in the device-dependent chunk of configuration space.  makes

> As has been pointed out, even delaying the allocation until after
> all other attachments have been done will guarantee that you
> can find free I/O space, but it's the best I've been able to come
> up with.

Yah, for now.

You notion of where things can be mapped isn't quite good enough, i
don't think.  for instance, if the card is behind a PPB, you need to
limit it to the space that the PPB is forwarding.

In general, we need a better way to do PCI bus reconfiguration
(i.e. BAR reprogramming), because more and more PCs aren't completely
configuring their PCI busses...

It's non-trivial to do it right, though.

Chris Demetriou - -
Disclaimer: Not speaking for NetBSD, just expressing my own opinion.