.\"     $OpenBSD: mpbios.4,v 1.1 2009/01/13 13:57:03 kettenis Exp $
.\"
.\" Copyright (c) 2009 Mark Kettenis <kettenis@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: January 13 2009 $
.Dt MPBIOS 4 amd64
.Os
.Sh NAME
.Nm mpbios
.Nd MP BIOS
.Sh SYNOPSIS
.Cd "mpbios0 at bios0"
.Sh DESCRIPTION
The
.Nm
driver extracts configuration information from the BIOS on
multiprocessor systems that conform to the Intel MultiProcessor
Specification.
This information is used to attach application processors and APICs,
and to assign interrupts to ISA, EISA and PCI devices.
.Pp
On modern systems this information is provided by ACPI through the
.Xr acpimadt 4
device.
On such a system
.Nm
will not attach, even if the BIOS also contains the data structures
specified by the Intel MP Specification.
.Pp
The
.Nm
driver supports version 1.1 and 1.4 of the Intel MP Specification.
.Sh SEE ALSO
.Xr acpi 4 ,
.Xr acpimadt 4 ,
.Xr bios 4 ,
.Xr cpu 4 ,
.Xr intro 4 ,
.Xr ioapic 4
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 4.5 ,
based on code present since
.Ox 3.6 .