pnp(4)

NAME

pnp - support for ``Plug and Play'' (PnP) ISA devices

DESCRIPTION

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 de

vice 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.

CAVEATS

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.

SEE ALSO

pnpbios(4)

STANDARDS

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.

HISTORY

The pnp driver first appeared in FreeBSD 2.2.5. It has been

substantially updated in subsequent versions.

AUTHORS

PnP support was originally written for FreeBSD 2.2.5 by Lui

gi Rizzo,
based on initial work done by
Sujal Patel.

BSD September 20, 2001

BSD