.\"	$NetBSD: drm.4,v 1.4 2007/03/29 18:35:08 wiz Exp $
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.\" Copyright (c) 2007 Thomas Klausner
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.Dd March 28, 2007
.Dt DRM 4
.Os
.Sh NAME
.Nm drm
.Nd Direct Rendering Manager (DRI kernel support)
.Sh SYNOPSIS
.Cd i915drm*       at vga?
.Cd mach64drm*     at vga?
.Cd mgadrm*        at vga?
.Cd r128drm*       at vga?
.Cd radeondrm*     at vga?
.Cd savagedrm*     at vga?
.Cd sisdrm*        at vga?
.Cd tdfxdrm*       at vga?
.Cd viadrm*        at vga?
.Pp
.Cd options        DRM_DEBUG
.Sh DESCRIPTION
The
.Tn Direct Rendering Manager
is part of the
.Tn Direct Rendering Infrastructure
(see
.Pa http://dri.freedesktop.org/ )
for supporting video acceleration (3d acceleration, mostly).
.Pp
The
.Nm
drivers provide support for the following chipsets:
.Bl -tag -width XsavagedrmXXX -offset indent -compact
.It i915drm
Intel i915, i945
.It mach64drm
Mach64 (3D Rage Pro, Rage)
.It mgadrm
Matrox G[24]00, G[45]50
.It r128drm
ATI Rage 128
.It radeondrm
ATI Radeon
.It savagedrm
S3 Savage
.It sisdrm
SiS
.It tdfxdrm
3dfx (Voodoo)
.It viadrm
VIA
.El
.Pp
To make use of the driver,
.Xr X 7
must be compiled with DRI support, Mesa DRI drivers must be installed,
the appropriate
.Pa /dev/dri/card*
device must exist, and DRI must be enabled in the X configuration
file.
.Pp
Details for these steps:
.Bl -enum -offset indent
.It
X must be compiled with DRI support.
On i386, this is usually the default.
.It
Mesa (see
.Pa http://www.mesa3d.org/ )
should be compiled for the netbsd-dri target, patch available at
.Pa http://issc.uj.ac.za/~yorick/drm/mesa.patch
.It
The device node must exist:
.Bd -literal -offset indent
mkdir -p /dev/dri
mknod /dev/dri/card0 c 180 0
chgrp wheel /dev/dri/card0
chmod 0660 /dev/dri/card0
.Ed
.It
Enable DRI in the X configuration (either
.Pa xorg.conf
or
.Pa XF86Config ) :
.Bd -literal
Section "Module"
        ...
        Load  "dri"
        Load  "GLcore"
        Load  "glx"
EndSection
...
Section "DRI"
        Group "wheel"
        Mode 0660
EndSection
.Ed
.El
.Pp
Debugging output can be enabled and disabled by setting the
.Xr sysctl 8
node
.Ar hw.dri.debug .
Additional information can be obtained from the
.Xr sysctl 8
nodes
.Ar hw.dri ,
.Ar hw.dri.card0 ,
.Ar hw.dri.card1 ,
etc.
.Sh SEE ALSO
.Xr X 7
.Sh HISTORY
DRM was first available for Linux.
Subsequently Eric Anholt ported the DRM kernel modules to
.Fx .
Erik Reid adapted the
.Fx
DRM kernel modules to
.Nx .
As DRM continued to develop the
.Nx
support was neglected.
Tonnerre Lombard got the DRM modules working again, but DRM
development once again left the
.Nx
support behind.
Finally Yorick Hardy took the
.Fx
DRM source and managed to get it compiling and working again on
.Nx ,
thanks largely to the efforts of all those mentioned above.
Subsequently Matthias Drochner improved the DRM file hierarchy for
.Nx
and committed the DRM kernel drivers.
.Pp
The
.Nm
drivers appeared in
.Nx 5.0 .
.Sh AUTHORS
.An -nosplit
.An Eric Anholt ,
.An Terry Barnaby ,
.An Erdi Chen ,
.An Michel Daenzer ,
.An Leif Delgass ,
.An Frank C. Earl ,
.An Rickard E. Faith ,
.An Jose Fonseca ,
.An Nicolai Haehnle ,
.An Jeff Hartmann ,
.An Thomas Hellstrom ,
.An Gareth Hughes ,
.An Felix Kuehling ,
.An Sung-Ching Lin ,
.An Kevin E. Martin ,
.An Jared D. McNeill ,
.An Daryll Strauss ,
.An Keith Whitwell
.Sh CAVEATS
Disable AIGLX if necessary
.Pq Pa xorg.conf :
.Bd -literal -offset indent
Section "ServerFlags"
        Option  "AIGLX" "off"
EndSection

Section "Extensions"
        Option "Composite" "Disable"
EndSection
.Ed
.Pp
In case of errors,
.Pa /dev/dri/card0
may be changed, make sure to recreate it in that case.
.Pp
.Cd options DRM_DEBUG
can slow DRI down a lot, disable it once
.Nm
works.