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       openchrome - video driver for VIA Unichromes

       Section "Device"
	 Identifier "devname"
	 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/KM400A/P4M800,	CN400/PM800/PN800/PM880,       K8M800,
       CN700/VM800/P4M800Pro,  CX700,  P4M890,	 K8M890,   P4M900/VN896/CN896,
       VX800,  VX855  and  VX900.   The	driver includes	2D acceleration	and Xv
       video overlay extensions.  Flat panel, TV, and  VGA  outputs  are  sup-
       ported, depending on the	hardware configuration.

       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 ap-
       ply for both Unichromes and Unichrome Pros.

       Please  refer  to xorg.conf(5) 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
	      downloads	 (if  DRI is enabled) and for the Render/Composite ex-

       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"	is for	laptop
	      panels  (not TFT screens attached	to the VGA port), "DFP"	is for
	      screens connected	to the DVI  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.   The  DVI  port is not properly probed and needs to	be en-
	      abled with this option.

       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  "En-
	      ableAGPDMA" 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 de-
	      fault amount of AGP is 32768 kB.	Note that the AGP aperture set
	      in the BIOS must be able to accommodate 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  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 de-
	      fault on the KM400 and K8M800 chipsets.)

       Option "DisableVQ"  "boolean"
	      Disables the use of the virtual command queue.  The queue	is en-
	      abled 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 de-
	      fault, 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 starting	from Xorg server  version  1.3.0  this
	      defaults	to "always".  The openchrome driver performs best with
	      "greedy",	so you should really add this option to	your  configu-
	      ration file.  The	third possibility is "smart".

       Option "NoAccel"	 "boolean"
	      Disables	the use	of hardware acceleration.  Acceleration	is en-
	      abled 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 "RotationType"  "string"
	      Enabled  rotation	 by using RandR. The driver only support unac-
	      celerated	 RandR	 rotations   "SWRandR".	  Hardware   rotations
	      "HWRandR"	is currently unimplemented.

       Option "Rotate"	"string"
	      Rotates  the  display  either clockwise ("CW"), counterclockwise
	      ("CCW") and upside-down ("UD"). Rotation is only supported unac-
	      celerated.   Adding option "Rotate", enables RandR rotation fea-
	      ture.  The RandR allows clients to dynamically change X screens.

       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 de-
	      flicker, 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 "TVPort"	"string"
	      Specifies	 TV  port.   The  driver  currently  supports  "DVP0",
	      "DVP1", "DFPHigh"	and "DFPLow" ports.

       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  ex-
	      tremely 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 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  (un-
	      scaled with only minimal overscan).  These modes are made	avail-
	      able by the driver; modelines provided in	xorg.conf will be  ig-

       Xorg(1),	xorg.conf(5), Xserver(1), X(7),	EXA(5),	Xv(5)

       Authors include:	...

X Version 11		  xf86-video-openchrome	0.6.0		OPENCHROME(4x)


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