MPBIOS(4)             OpenBSD Programmer's Manual (AMD64)            MPBIOS(4)

NAME
     mpbios - MP BIOS

SYNOPSIS
     mpbios0 at bios0

DESCRIPTION
     The mpbios driver extracts configuration information from the BIOS on
     multiprocessor systems that conform to the Intel MultiProcessor Specifi-
     cation.  This information is used to attach application processors and
     APICs, and to assign interrupts to ISA, EISA and PCI devices.

     On modern systems this information is provided by ACPI through the
     acpimadt(4) device.  On such a system mpbios will not attach, even if the
     BIOS also contains the data structures specified by the Intel MP Specifi-
     cation.

     The mpbios driver supports version 1.1 and 1.4 of the Intel MP Specifica-
     tion.

SEE ALSO
     acpi(4), acpimadt(4), bios(4), cpu(4), intro(4), ioapic(4)

HISTORY
     The mpbios driver first appeared in OpenBSD 4.5, based on code present
     since OpenBSD 3.6.

OpenBSD 4.7                    January 13, 2009                              1
