Provided by: weston_9.0.0-4ubuntu1_amd64 bug

NAME

       weston-drm - the DRM backend for Weston

SYNOPSIS

       weston-launch

       weston --backend=drm-backend.so

DESCRIPTION

       The  DRM  backend  is  the native Weston backend for systems that support the Linux kernel
       DRM, kernel mode setting (KMS), and evdev input devices.  It is  the  recommended  backend
       for  desktop PCs, and aims to provide the full Wayland experience with the "every frame is
       perfect" concept.  It also relies on the Mesa GBM interface.

       With the DRM backend, weston runs without any underlying  windowing  system.  The  backend
       uses  the  Linux  KMS API to detect connected monitors. Monitor hot-plugging is supported.
       Input devices are found automatically by udev(7).  Compositing happens mainly in  GL ES 2,
       initialized  through  EGL.  It  is also possible to take advantage of hardware cursors and
       overlays, when they exist and are functional. Full-screen surfaces  will  be  scanned  out
       directly  without  compositing, when possible.  Hardware accelerated clients are supported
       via EGL.

       The backend chooses the DRM graphics device first based on seat id.  If  seat  identifiers
       are not set, it looks for the graphics device that was used in boot. If that is not found,
       it finally chooses the first DRM device returned by udev(7).  Combining multiple  graphics
       devices is not supported yet.

       The  DRM  backend  relies on weston-launch for managing input device access and DRM master
       status, so that weston can be run without root privileges.  On  switching  away  from  the
       virtual  terminal  (VT)  hosting  Weston,  all input devices are closed and the DRM master
       capability is dropped, so that other servers, including Xorg(1), can run on other VTs.  On
       switching  back  to  Weston's VT, input devices and DRM master are re-acquired through the
       parent process weston-launch.

       The DRM backend also supports virtual outputs that are transmitted over an RTP session  as
       a  series  of  JPEG  images  (RTP payload type 26) to a remote client. Virtual outputs are
       configured in the remote-output section of weston.ini.

CONFIGURATION

       The DRM backend uses the following entries from weston.ini.

   Section output
       name=connector
              The KMS connector name identifying the output, for instance LVDS1.

       mode=mode
              Specify the video mode for the output. The argument mode can be one  of  the  words
              off to turn the output off, preferred to use the monitor's preferred video mode, or
              current to use the current video mode and avoid a mode switch.  It can  also  be  a
              resolution as:

       mode=widthxheight

       mode=widthxheight@refresh_rate
              Specify a mode with a given refresh-rate measured in Hz.

       mode=widthxheight@refresh_rate ratio
              Here  ratio  is Picture Aspect-Ratio which can have values as 4:3, 16:9, 64:27, and
              256:135. This resolution-format helps to select a CEA mode, if such a video mode is
              present in the mode-list of the output.

              CEA  defines the timing of a video mode, which is considered as a standard for HDMI
              spcification and compliance testing. It defines each and every parameter of a video
              mode,   like   hactive,   vactive,   vfront,  vback  etc.,  including  aspect-ratio
              information. For CEA modes, the drm layer, stores this aspect-ratio information  in
              user-mode  (drmModeModeInfo) flag bits 19-22. For the non-CEA modes a value of 0 is
              stored in the aspect-ratio flag bits.

              Each CEA-mode is identified by a unique,  Video  Identification  Code  (VIC).   For
              example, VIC=4 is 1280x720@60 aspect-ratio 16:9. This mode will be different than a
              non-CEA mode 1280x720@60 0:0. When the video mode 1280x720@60 0:0 is applied, since
              its  timing  doesn't  exactly match with the CEA information for VIC=4, it would be
              treated as a  non-CEA  mode.  Also,  while  setting  the  HDMI-AVI-Inforframe,  VIC
              parameter  will be given as '0'. If video mode 1280x720@60 16:9 is applied, its CEA
              timimgs matches with that of video mode with VIC=4, so the VIC parameter  in  HDMI-
              AVI-Infoframe will be set to 4.

              Many  a  times, an output may have both CEA and non-CEA modes, which are similar in
              all resepct, differing only in the aspect-ratio. A user can select a  CEA  mode  by
              giving  the aspect-ratio, along with the other arguments for the mode.  By omitting
              the  aspect-ratio,  user  can  specify  the  non-CEA  modes.    This   helps   when
              certification  testing  is  done,  in  tests like 7-27, the HDMI-analyzer applies a
              particular CEA mode, and expects the applied mode to be with exactly same  timings,
              including the aspect-ratio and VIC field.

              The resolution can also be a detailed mode line as below.

       mode=dotclock  hdisp  hsyncstart  hsyncend  htotal  vdisp vsyncstart vsyncend vtotal hflag
       vflag
              Use the given detailed mode line as the video mode for this output.  The definition
              is the same as in xorg.conf(5), and cvt(1) can generate detailed mode lines.

       transform=transform
              Transform  for  the  output,  which  can be rotated in 90-degree steps and possibly
              flipped. Possible values are normal, rotate-90,  rotate-180,  rotate-270,  flipped,
              flipped-rotate-90, flipped-rotate-180, and flipped-rotate-270.

       pixman-shadow=boolean
              If using the Pixman-renderer, use shadow framebuffers. Defaults to true.

       same-as=name
              Make  this  output  (connector)  a  clone of another. The argument name is the name
              value of another output section. The referred to output section  must  exist.  When
              this  key  is  present  in  an output section, all other keys have no effect on the
              configuration.

              NOTE: cms-colord plugin does not  work  correctly  with  this  option.  The  plugin
              chooses  an  arbitrary  monitor  to  load the color profile for, but the profile is
              applied equally to all cloned monitors regardless of their properties.

       force-on=true
              Force the output to be enabled even if the connector is disconnected.  Defaults  to
              false.  Note  that  mode=off  will  override  force-on=true.   When  a connector is
              disconnected, there is no EDID information  to  provide  a  list  of  video  modes.
              Therefore a forced output should also have a detailed mode line specified.

   Section remote-output
       name=name
              Specify unique name for the output.

       mode=mode
              Specify  the  video mode for the output. The argument mode is a resolution setting,
              such as:

       mode=widthxheight

       mode=widthxheight@refresh_rate
              If refresh_rate is not specified it will default to a 60Hz.

       host=host
              Specify the host name or IP Address that the remote output will be transmitted to.

       port=port
              Specify the port number to transmit the remote output  to.  Usable  port  range  is
              1-65533.

       gst-pipeline=pipeline
              Specify  the gstreamer pipeline. It is necessary that source is appsrc, its name is
              "src", and sink name is "sink" in pipeline.  Ignore port and host configuration  if
              the gst-pipeline is specified.

OPTIONS

       When  the  DRM  backend is loaded, weston will understand the following additional command
       line options.

       --current-mode
              By default, use the current video mode of all outputs, instead of switching to  the
              monitor preferred mode.

       --drm-device=cardN
              Use  the  DRM  device  cardN  instead  of  the  default  heuristics  based  on seat
              assignments and boot VGA status. For example, use card0.

       --seat=seatid
              Use graphics and input devices designated for  seat  seatid  instead  of  the  seat
              defined  in  the environment variable XDG_SEAT. If neither is specified, seat0 will
              be assumed.

       --tty=x
              Launch Weston on tty x instead of using the current tty.

       --continue-without-input
              Allow Weston to start without input devices. Used for testing purposes.

ENVIRONMENT

       WESTON_LIBINPUT_LOG_PRIORITY
              The minimum libinput verbosity level to be printed to Weston's log.   Valid  values
              are debug, info, and error. Default is info.

       WESTON_TTY_FD
              The  file  descriptor  (integer)  of  the  opened tty where weston will run. Set by
              weston-launch.

       WESTON_LAUNCHER_SOCK
              The file descriptor (integer) where weston-launch is listening.  Automatically  set
              by weston-launch.

       XDG_SEAT
              The seat Weston will start on, unless overridden on the command line.

SEE ALSO

       weston(1)