- NetBSD Manual Pages
DRM(4) NetBSD Kernel Interfaces Manual DRM(4)
Powered by man-cgi (2021-06-01).
Maintained for NetBSD
by Kimmo Suominen.
Based on man-cgi by Panagiotis Christias.
drm -- Direct Rendering Manager (DRI kernel support)
i915drm* at drm?
mach64drm* at drm?
mgadrm* at drm?
r128drm* at drm?
radeondrm* at drm?
savagedrm* at drm?
sisdrm* at drm?
tdfxdrm* at drm?
The Direct Rendering Manager is part of the Direct Rendering Infrastruc-
ture for supporting video acceleration (3d acceleration, mostly).
The drm drivers provide support for the following chipsets:
i915drm Intel i915, i945
mach64drm Mach64 (3D Rage Pro, Rage)
mgadrm Matrox G00, G50
r128drm ATI Rage 128
radeondrm ATI Radeon
savagedrm S3 Savage
tdfxdrm 3dfx (Voodoo)
To make use of the driver, the kernel must include agp(4) (for some driv-
ers, using options DRM_NO_AGP instead may be sufficient), X(7) must be
compiled with DRI support, Mesa DRI drivers must be installed, the appro-
priate /dev/dri/card* device must exist, and DRI must be enabled in the X
configuration file. X(7) provided with NetBSD and compiled from
pkgsrc(7) do so automatically where supported.
With some drivers (at least radeon(4)), in some cases the driver does not
choose the resolution correctly. The options
DRM_MAX_RESOLUTION_HORIZONTAL and DRM_MAX_RESOLUTION_VERTICAL allow lim-
iting the maximum resolution in X and Y direction.
X(7) will attempt to create the device node automatically. To create the
device node manually:
mkdir -p /dev/dri
mknod /dev/dri/card0 c 180 0
chgrp wheel /dev/dri/card0
chmod 0660 /dev/dri/card0
To enable DRI in the X configuration add the following to either
xorg.conf for Xorg(1) or XF86Config for XFree86(1) :
Debugging output can be enabled and disabled by setting the sysctl(8)
node hw.dri.debug. Additional information can be obtained from the
sysctl(8) nodes hw.dri, hw.dri.card0, hw.dri.card1, etc.
XFree86(1), Xorg(1), agp(4), XF86Config(5), xorg.conf(5), X(7),
Direct Rendering Infrastructure:
DRM was first available for Linux. Subsequently Eric Anholt ported the
DRM kernel modules to FreeBSD. Erik Reid adapted the FreeBSD DRM kernel
modules to NetBSD. As DRM continued to develop the NetBSD support was
neglected. Tonnerre Lombard got the DRM modules working again, but DRM
development once again left the NetBSD support behind. Finally Yorick
Hardy took the FreeBSD DRM source and managed to get it compiling and
working again on NetBSD, thanks largely to the efforts of all those men-
tioned above. Subsequently Matthias Drochner improved the DRM file hier-
archy for NetBSD and committed the DRM kernel drivers. Matthew Green
cleaned up this port and merged a set of newer drivers, with Arto Huusko
and FUKAUMI Naoki helping to get the latest Mesa port up to date.
The drm drivers appeared in NetBSD 5.0.
Eric Anholt, Terry Barnaby, Erdi Chen, Michel Daenzer, Leif Delgass,
Frank C. Earl, Rickard E. Faith, Jose Fonseca, Nicolai Haehnle, Jeff
Hartmann, Thomas Hellstrom, Gareth Hughes, Felix Kuehling, Sung-Ching
Lin, Kevin E. Martin, Daryll Strauss, Keith Whitwell
In case of errors, /dev/dri/card0 may be changed, make sure to recreate
it in that case.
options DRM_DEBUG can slow DRI down a lot; disable it once drm works.
NetBSD 10.99 March 10, 2021 NetBSD 10.99