There is now some code in the NetBSD-current tree to make use of
the Plug-and-Play BIOS present in practically all PC compatibles
of the last couple of years.

The PnP BIOS provides information about hardware on the
mainboard - device types and resource usage.
(For reference, see http://www.microsoft.com/hwdev/respec/pnpspecs.htm)
This way, ISA devices with unusual wiring can be accessed
properly, and (potentially harmful) device probing can be
avoided.
The PnP BIOS support has been found most useful on
laptops, where it seems common that interrupts are wired
in strange ways. It shouldn't do any harm on other machines
-- you know there is that other operating system which
depends heavily on Plug-and-Pray.

It is young code however, the PnP BIOSes are of varying
quality, and the specification is not clear in all details
(and only partly obeyed by BIOS vendors). So keep a working
kernel around if you play with this...

The NetBSD PnP BIOS support is implemented as a logical bus
named "pnpbios", it will be switched on by a line

pnpbios0 at mainbus0

in the kernel configuration file. For now, only a few device
attachments are implemented - see the comments in conf/GENERIC
or the contents of i386/pnpbios/ for details. The kernel option

options PNPBIOSVERBOSE

causes all devices nodes to be reported in the boot log,
and their resource usage. To interpret the PnP IDs,
http://www.microsoft.com/hwdev/download/respec/devids.txt
might be of some help.
Have a look at devices with unusual resource usage - these
might be worth writing some attachment code.

As usual, report any problems you find.

best regards
Matthias