pnp —
support
for “Plug and Play” (PnP) ISA devices
The
pnp driver enumerates ISA devices which support
“Plug and Play ISA Specification” in the system. It assigns ISA
bus resources (interrupt line, DMA channel, I/O ports, and memory region) to
each device and activates it.
If it cannot assign necessary resources to a PnP ISA device without causing
conflict with other devices in the system, the device will not be activated
and will be unavailable to programs.
pnpbios(4)
Intel and
Microsoft, Plug and Play ISA
Specification, Version 1.0a, May 5,
1994.
Clarifications to the Plug and
Play ISA Specification, Version 1.0a, December 10,
1994.
The
pnp driver first appeared in
FreeBSD 2.2.5. It has been substantially updated in
subsequent versions.
PnP support was originally written for
FreeBSD 2.2.5 by
Luigi Rizzo, based on initial work done by
Sujal Patel.
It is not possible to disable individual PnP ISA devices. The
pnp driver will find all devices conforming the
PnP ISA specification and try to activate them all.
There is no way to explicitly assign particular resource to the PnP ISA device.
The resource assignment is fully automatic and there is no provision for
manual override.