On Tue 24 Nov 1998, Lennart Augustsson wrote:

> In the attach code I don't allocate any I/O regions since we can't
> really tell what's free until all drivers have had a chance to attach,
> instead I call config_defer() to delay the allocation.

The problem is that you can't tell whats free unless you actually make a
pass over the pci-bus recording the used regions! If there is a card on
your pci-bus that is not supported by NetBSD but is initialized by your
pci-bios, the physical address space is claimed.
Another complication is the presence of legacy cards like VGA. Sometimes
these cards claim memory while not recording it in the pci-registers :-(
On the atari (where I have to do some pci-bios-ing of my own), I reserve
the 16MB memory and 64KB I/O space for these cards on the bottom of the
regions.

Leo.