> Um. What, exactly, is the info from a pcibios useful for? 
> rerouting interrupts,

Yes.

> Can we use pcibios callbacks to initialize bridge devices (for
> example, CardBus bigdges) whose BARs were not set by the normal
> boot-time PCI initialization done by the BIOS? That is one of the
> immediate gotchas for several NetBSD laptop users who could otherwise
> use hardware-pcic-compatibility to support PCMCIA cards in their
> cardbus slots.

The pcibios.c can be used when the IRQ of cardbus bridge (or other
device) is not set by BIOS. It is known to save same laptops.
But also it is known that there are machines which doesn't work with
this feature.

The newconfig repository can be also accessed via FTP:
	ftp://ftp.sra.co.jp/os/FreeBSD/FreeBSD-CVS-jp/newconfig/sys/i386/
		pci/pcibios.[ch],v	-- the source of pcibios.c
		pci/pci_machdep.c,v	-- the source which calls the pcibios.c
		pci/pci_access.c,v	-- the source which calls the pcibios.c
		i386/mainbus.c,v	-- the source which calls the pcibios.c
--
soda