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DRM(4)                       Device Drivers Manual                      DRM(4)

     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?

     options DRM_DEBUG
     options DRM_NO_AGP
     options DRM_MAX_RESOLUTION_VERTICAL=integer

     The Direct Rendering Manager is part of the Direct Rendering
     Infrastructure for supporting video acceleration (3d acceleration,

     The drm drivers provide support for the following chipsets:
           i915drm        Intel i915, i945
           mach64drm      Mach64 (3D Rage Pro, Rage)
           mgadrm         Matrox G[24]00, G[45]50
           r128drm        ATI Rage 128
           radeondrm      ATI Radeon
           savagedrm      S3 Savage
           sisdrm         SiS
           tdfxdrm        3dfx (Voodoo)
           viadrm         VIA

     To make use of the driver, the kernel must include agp(4) (for some
     drivers, using options DRM_NO_AGP instead may be sufficient), X(7) must
     be compiled with DRI support, Mesa DRI drivers must be installed, the
     appropriate /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
     limiting 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) :

           Section "Module"
                   Load  "dri"
                   Load  "dri2"
                   Load  "glx"
           Section "DRI"
                   Group "wheel"
                   Mode 0660

     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: http://dri.freedesktop.org/

     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
     mentioned above.  Subsequently Matthias Drochner improved the DRM file
     hierarchy 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 9.99                     March 10, 2021                     NetBSD 9.99