Provided by: xserver-xorg-video-openchrome_0.2.901-0ubuntu4_i386 bug


       openchrome - video driver for VIA Unichromes


       Section "Device"
         Identifier "string"
         Driver "openchrome"


       openchrome  is an Xorg driver for VIA chipsets that have  an integrated
       Unichrome graphics engine.

       The  openchrome  driver  supports  the  following   chipsets:   CLE266,
       KM400/KN400,   CN400,  CN700,  K8M800/K8N800,  PM800/PN800,  P4M800Pro,
       VN800, PM880, K8M890/K8N890, CN896,  VN896,  and  P4M900.   The  driver
       includes  2D acceleration and Xv video overlay extensions.  Flat panel,
       TV,  and  VGA  outputs  are  supported,  depending  on   the   hardware

       3D  direct  rendering is available using experimental drivers from Mesa
       (  There is also an XvMC client  library  for  hardware
       acceleration  of  MPEG1/MPEG2  decoding  (not available on the KM/N400)
       that uses the Direct Rendering Infrastructure (DRI).  The  XvMC  client
       library implements a non-standard "VLD" extension to the XvMC standard.
       The current Direct Rendering Manager (DRM) kernel module  is  available

       The  driver  supports free modes for Unichrome Pros (K8M/N800, PM/N800,
       and CN400).  For  plain  Unichromes  (CLE266,  KM/N400),  it  currently
       supports  only  a  limited  number  of dotclocks, so if you are using X
       modelines you must  make  sure  that  the  dotclock  is  one  of  those
       supported.   Supported  dotclocks on plain Unichromes are currently (in
       MHz): 25.2, 25.312, 26.591, 31.5, 31.704, 32.663, 33.750,  35.5,  36.0,
       39.822,  40.0,  41.164, 46.981, 49.5, 50.0, 56.3, 57.284, 64.995, 65.0,
       65.028,  74.480,  75.0,  78.8,  81.613,  94.5,  108.0,  108.28,  122.0,
       122.726,  135.0,  148.5,  155.8,  157.5,  161.793, 162.0, 175.5, 189.0,
       202.5, 204.8, 218.3, 229.5.  On top  of  this,  bandwidth  restrictions
       apply for both Unichromes and Unichrome Pros.


       Please  refer  to  xorg.conf() for general configuration details.  This
       section only covers configuration details specific to this driver.

       The following driver options are supported:

       Option "AccelMethod"  "string"
              The driver supports "XAA" and "EXA" acceleration  methods.   The
              default   method  is  XAA,  since  EXA  is  still  experimental.
              Contrary to XAA, EXA implements acceleration for screen  uploads
              and  downlads  (if  DRI is enabled) and for the Render/Composite

       Option "ActiveDevice"  "string"
              Specifies the active device combination.  Any string  containing
              "CRT",  "LCD",  "DFP", "TV" should be possible. "CRT" represents
              anything that is connected to the VGA port, "LCD" and "DFP"  are
              for  laptop  panels  (not TFT screens attached to the VGA port),
              "TV" is  self-explanatory.   The  default  is  to  use  what  is
              detected.   The  driver  is  currently  unable to use LCD and TV
              simultaneously, and will favour the LCD.

       Option "AGPMem"  "integer"
              Sets the amount of AGP memory that  is  allocated  at  X  server
              startup.   The  allocated memory will be "integer" kB.  This AGP
              memory  is  used  for  the  AGP  command   buffer   (if   option
              "EnableAGPDMA"  is set to "true"), for DRI textures, and for the
              EXA scratch area.  The driver will allocate at least one  system
              page  of  AGP  memory and, if the AGP command buffer is used, at
              least 2MB + one system page.  If there is no room  for  the  EXA
              scratch  area  in AGP space, it will be allocated from VRAM.  If
              there is no room for DRI textures, they will be  allocated  from
              the  DRI part of VRAM (see the option "MaxDRIMem").  The default
              amount of AGP is 32768kB.  Note that the AGP aperture set in the
              BIOS  must  be  able  to  accomodate  the  amount  of AGP memory
              specified here.  Otherwise no AGP memory will be available.   It
              is safe to set a very large AGP aperture in the BIOS.

       Option "Center"  "boolean"
              Enables or disables image centering on DVI displays.

       Option "DisableIRQ"  "boolean"
              Disables  the  Vblank  IRQ.   This  is  a  workaround  for  some
              mainboards that have  problems  with  IRQs  from  the  Unichrome
              engine.   With  IRQs  disabled,  DRI  clients  have  no  way  to
              synchronize drawing to  Vblank.   (This  option  is  enabled  by
              default on the KM400 and K8M800 chipsets.)

       Option "DisableVQ"  "boolean"
              Disables the use of VQ.  VQ is enabled by default.

       Option "EnableAGPDMA"  "boolean"
              Enables  the  AGP  DMA functionality in DRM.  This requires that
              DRI is enabled and will force 2D and 3D acceleration to use  AGP
              DMA.   The  XvMC  DRI  client  will also make use of this on the
              CLE266 to consume much less CPU.  (This  option  is  enabled  by
              default on all chipsets except the K8M890 and P4M900.)

       Option "ExaNoComposite"  "boolean"
              If  EXA is enabled (using the option "AccelMethod"), this option
              enables or disables acceleration of compositing.  Since EXA, and
              in particular its composite acceleration, is still experimental,
              this is a way to disable a misbehaving composite acceleration.

       Option "ExaScratchSize"  "integer"
              Sets the size of the EXA scratch area  to  "integer"  kB.   This
              area  is used by EXA as a last place to look for available space
              for pixmaps.  Too little space will slow compositing down.  This
              option should be set to the size of the largest pixmap used.  If
              you have a screen width of over 1024 pixels and use 24 bpp,  set
              this to 8192.  Otherwise you can leave this at the default 4096.
              The space will  be  allocated  from  AGP  memory  if  available,
              otherwise from VRAM.

       Option "HWCursor"  "boolean"
              Enables or disables the use of hardware cursors.  The default is

       Option "LCDDualEdge"  "boolean"
              Enables or disables the use of dual-edge mode to set the LCD.

       Option "MaxDRIMem"  "integer"
              Sets the maximum amount of VRAM memory allocated for DRI clients
              to  "integer"  kB.  Normally DRI clients  get half the available
              VRAM size, but in some cases it may make  sense  to  limit  this
              amount.   For  example, if you are using a composite manager and
              you want to give as much memory as possible to  the  EXA  pixmap
              storage area.

       Option "MigrationHeuristic"  "string"
              Sets  the  heuristic  for  EXA pixmap migration.  This is an EXA
              core option, and on  Xorg  xserver  versions  after  1.1.0  this
              defaults  to  "smart".  The Openchrome driver performs best with
              "greedy",  so  you  should  really  add  this  option  to   your
              configuration  file.   The  third possibility is "always", which
              might become more useful in the future.

       Option "NoAccel"  "boolean"
              Disables or  enables  acceleration.   Default:  acceleration  is

       Option "NoAGPFor2D"  "boolean"
              With  this option set, 2D acceleration will not use AGP DMA even
              if it is enabled.

       Option "NoXVDMA"  "boolean"
              If DRI is enabled, Xv normally uses PCI DMA  to  transfer  video
              images  from  system  to  frame-buffer memory.  This is somewhat
              slower than direct copies due to the limitations of the PCI bus,
              but  on  the  other  hand  it decreases CPU usage significantly,
              particularly on computers  with  fast  processors.   Some  video
              players  are buggy and will display rendering artifacts when PCI
              DMA is used.  If you experience this, or don’t want your PCI bus
              to  be stressed with Xv images, set this option to "true".  This
              option has no effect when DRI is not enabled.

       Option "PanelSize"  "string"
              Specifies the size (width x height) of the LCD panel attached to
              the  system.   The  sizes 640x480, 800x600, 1024x768, 1280x1024,
              and 1400x1050 are supported.

       Option "Rotate"  "string"
              Rotates the display either clockwise ("CW") or  counterclockwise
              ("CCW").  Rotation is only supported unaccelerated.

       Option "ShadowFB"  "boolean"
              Uses  a shadow frame buffer.  This is required when rotating the
              display, but otherwise defaults to disabled.

       Option "SWCursor"  "boolean"
              Enables or disables the use of a software cursor.   The  default
              is disabled.

       Option "TVDeflicker"  "integer"
              Specifies the deflicker setting for TV output.  Valid values are
              "0", "1", and "2".  0) No  deflicker,  1)  1:1:1  deflicker,  2)
              1:2:1 deflicker.

       Option "TVDotCrawl"  "boolean"
              Enables or disables dotcrawl.

       Option "TVOutput"  "string"
              Specifies  which  TV  output  to  use.   The driver supports "S-
              Video", "Composite", "SC", "RGB" and "YCbCr" outputs.  Note that
              on  some  EPIA  boards  the compositer-video port is shared with
              audio-out and is selected via a jumper.

       Option "TVType"  "string"
              Specifies TV  output  format.   The  driver  currently  supports
              "NTSC" and "PAL" timings only.

       Option "VBEModes"  "boolean"
              Uses  the  VBE  BIOS calls to set the display mode.  This mimics
              the behaviour of  the  vesa  video  driver  but  still  provides
              acceleration  and  other  features.   This option may be used if
              your hardware works with  the  vesa  driver  but  not  with  the
              Openchrome  driver.   It  may not work on 64-bit systems.  Using
              "VBEModes" may speed up driver acceleration significantly due to
              a more aggressive hardware setting, particularly on systems with
              low memory bandwidth.  Your refresh rate may be limited to 60 Hz
              on some systems.

       Option "VBESaveRestore"  "boolean"
              Uses  the  VBE  BIOS calls to save and restore the display state
              when the X server is launched.  This can be  extremely  slow  on
              some  hardware,  and the system may appear to have locked for 10
              seconds or so.   The  default  is  to  use  the  driver  builtin
              function.   This  option  only  works  if  option  "VBEModes" is

       Option "VideoRAM"  "integer"
              Overrides the VideoRAM  autodetection.   This  should  never  be


       Unichromes tend to be paired with several different TV encoders.

       VIA Technologies VT1621
              Still  untested,  as no combination with a Unichrome is known or
              available.  Supports the following normal modes:  "640x480"  and
              "800x600".   Use  "640x480Over"  and  "800x600Over" for vertical
              overscan.   These  modes  are  made  available  by  the  driver;
              modelines provided in xorg.conf will be ignored.

       VIA Technologies VT1622, VT1622A, VT1623
              Supports  the following modes: "640x480", "800x600", "1024x768",
              "848x480", "720x480" (NTSC only) and "720x576" (PAL only).   Use
              "640x480Over",   "800x600Over",  "1024x768Over",  "848x480Over",
              "720x480Over"  (NTSC)  and  "720x576Over"  (PAL)  for   vertical
              overscan.      The    modes    "720x480Noscale"    (NTSC)    and
              "720x576Noscale"  (PAL)  (available  on  VT1622  only)   provide
              cleaner  TV output (unscaled with only minimal overscan).  These
              modes are made available by the driver;  modelines  provided  in
              xorg.conf will be ignored.


       Xorg(), xorg.conf(), xorgconfig(), Xserver(), X()


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