BIOS(4) BSD Programmer's Manual (i386) BIOS(4)NAMEbios - a driver for PC Firmware, aka BIOS
SYNOPSIS
bios0 at mainbus0 flags 0x0000
apm0 at bios0 flags 0x0000
pcibios0 at bios0 flags 0x0000
DESCRIPTION
OpenBSD provides support for PC firmware, aka BIOS and some of its func-
tions, currently: APM subsystem, BIOS 32 extensions, PCI BIOS subsystem.
The bios driver also identifies BIOS type (such as "AT/286+", which is
almost always used in modern machines) and BIOS image date stamp, which
is, presumably, the day the BIOS image was compiled by vendor and could
be used as a crude BIOS version identification. The bios driver also
scans the ISA memory hole at 640K-1M for optional ROM images and reserves
the space from being used by various ISA devices, for example pcic(4).
Flags is a bit mask each bit of which specifies which functions of the
driver to disable.
0x0001 BIOS 32 attachment.
Do not probe and attach to BIOS 32 extensions, which is one of
the interfaces to the PCI BIOS configuration tables.
0x0002 PCI BIOS attachment.
Do not probe and attach the pcibios(4) device, which performs
certain PCI configuration tasks.
0x0004 Do not perform the scan for ROM images in the ISA memory hole
(0xc0000 - 0xf0000 physical addresses).
SEE ALSOapm(4), intro(4), pcibios(4), pcmcia(4), powernowhack(4)HISTORY
The bios driver appeared in OpenBSD 2.2.
BUGS
On some machines optional ROM images do not pass checksum check, but it's
considered better to reserve space for those anyway, choosing lesser evil
from many.
MirOS BSD #10-current February 28, 2001 1