.\"	$OpenBSD: xf86.4,v 1.4 1998/06/29 06:57:02 angelos Exp $
.\"
.\" Copyright (c) 1998 Matthieu Herrb
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.Dd February 20, 1998
.Os OpenBSD 2.3
.Dt XF86 4 i386
.Sh NAME
.Nm xf86
.Nd
XFree86 aperture driver
.Sh SYNOPSIS
.Cd "option APERTURE"
.Sh DESCRIPTION
The 
.Pa /dev/xf86
driver provides access to the memory of a VGA board for
use by the XFree86 X servers 
when running with a kernel security level > 0 (ie. when using 
.Pa /dev/mem
is prohibited).
.Pp
Some X servers (
.Xr XF86_P9000 1 ,
.Xr XF86_Mach64 1 ,
.Xr XF86_AGX 1 ,
the Matrox driver in 
.Xr XF86_SVGA 1
)
require the use of this driver, while the other can make use of it if
it's available, but will work without it.
.Sh ACCESS CONTROL
Access to the 
.Pa /dev/xf86 
device is allowed when the sysctl variable
.Va machdep.allowaperture 
= 1. This variable (which default value is 0) 
can only be manipulated when the security level is <= 0, so it should be
set in 
.Pa /etc/sysctl.conf .
.Sh SEE ALSO
.Xr XF86_Accel 1 ,
.Xr XF86_SVGA 1 ,
.\" XXX .Xr sysctl.conf 5 ,
.Xr config 8 ,
.Xr options 4,
.Xr sysctl 8 .
.Sh HISTORY
.Pa /dev/xf86 
was introduced as a loadable kernel module for NetBSD 0.9C
with XFree86 3.1. It was integrated as an in-kernel device on
.Ox 2.3 .
.Sh AUTHOR
The aperture driver was written by Matthieu Herrb.
.Sh BUGS
This driver allows access to all addresses above
.Va physmem . 
It should be restricted to the actual address range of the video
memory.