PNPBIOS(4)                                               BSD/i386 Kernel Interfaces Manual                                              PNPBIOS(4)

NAME

     pnpbios -- support for embedded devices on the motherboard

DESCRIPTION

     The pnpbios driver enumerates embedded ISA devices on the motherboard whose BIOS supports ``Plug and Play BIOS Specification''.  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 device without causing conflict with other devices in the system, the device will not be acti-
     vated and will be unavailable to programs.

CAVEATS

     There is no explicit way to disable individual embedded devices.  The pnpbios driver will find all devices reported by the ``Plug and Play
     (PnP)'' BIOS and try to activate them all.

     There is no way to explicitly assign particular resource to a device.  The resource assignment is fully automatic and there is no provision
     for manual override.

SEE ALSO

     pnp(4)

STANDARDS

     Compaq, Phenix, and Intel, Plug and Play BIOS Specification Version 1.0A, May 5, 1994.

     Compaq, Phenix, and Intel, Plug and Play BIOS CLARIFICATION Paper for Plug and Play BIOS Specification Version 1.0A, October 6, 1994.

HISTORY

     The pnpbios driver first appeared in FreeBSD 4.0.

AUTHORS

     The pnpbios driver was written by Mike Smith.

BSD                                                             September 20, 2001                                                             BSD