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       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 configura-

       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 (K8M800/K8N800,
       PM800/PN800, and	CN400).	 For plain Unichromes  (CLE266,	 KM400/KN400),
       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.  Con-
	      trary to XAA, EXA	implements acceleration	for screen uploads and
	      downlads (if DRI is enabled) and for the Render/Composite	exten-

       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  the	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, or -- if the AGP command buffer is used --
	      at least 2 MB plus 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 32768 kB.  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	avail-
	      able.   It is safe to set	a very large AGP aperture in the BIOS.

       Option "Center"	"boolean"
	      Enables image centering on DVI displays.	The  default  is  dis-

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

       Option "DisableVQ"  "boolean"
	      Disables	the  use  of  the virtual command queue.  The queue 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, except on the K8M890 and	P4M900.)

       Option "ExaNoComposite"	"boolean"
	      If EXA is	enabled	(using the option "AccelMethod"), this	option
	      enables acceleration of compositing.  Since EXA, and in particu-
	      lar 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,	other-
	      wise from	VRAM.

       Option "LCDDualEdge"  "boolean"
	      Enables the use of dual-edge mode	to set the LCD.	  The  default
	      is disabled.

       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  server  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 configu-
	      ration file.  The	third possibility  is  "always",  which	 might
	      become more useful in the	future.

       Option "NoAccel"	 "boolean"
	      Disables	the  use  of  hardware	acceleration.  Acceleration is
	      enabled by default.

       Option "NoAGPFor2D"  "boolean"
	      Disables the use of AGP DMA for 2D acceleration, even  when  AGP
	      DMA is enabled.  The default 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, par-
	      ticularly	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"
	      Enables the use of a shadow frame	buffer.	 This is required when
	      rotating the display, but	otherwise defaults to disabled.

       Option "SWCursor"  "boolean"
	      Enables  the use of a software cursor.  The default is disabled:
	      the hardware cursor is used.

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

       Option "TVDotCrawl"  "boolean"
	      Enables dot-crawl	suppression.  The default is disabled.

       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 composite-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"
	      Enables the use of VBE BIOS calls	for setting the	display	 mode.
	      This  mimics the behaviour of the	vesa 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"
	      Enables the use of VBE BIOS calls	for saving and	restoring  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 "VBE-
	      Modes" is	enabled.

       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; mode-
	      lines 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 over-
	      scan.  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

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

       Authors include:	...

X Version 11		 xf86-video-openchrome 0.2.903		OPENCHROME(4x)


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