1OPENCHROME(4) Kernel Interfaces Manual OPENCHROME(4)
2
6 openchrome - video driver for VIA Unichromes
7
9 Section "Device"
10 Identifier "string"
11 Driver "openchrome"
12 ...
13 EndSection
14
17 openchrome is an Xorg driver for VIA chipsets that have an integrated
18 Unichrome graphics engine.
19 The openchrome driver supports the following chipsets: CLE266,
21 KM400/KN400, CN400, CN700, K8M800/K8N800, PM800/PN800, P4M800Pro,
22 VN800, PM880, K8M890/K8N890, CN896, VN896, and P4M900. The driver
23 includes 2D acceleration and Xv video overlay extensions. Flat panel,
24 TV, and VGA outputs are supported, depending on the hardware configura‐
25 tion.
26 3D direct rendering is available using experimental drivers from Mesa
28 (www.mesa3d.org). There is also an XvMC client library for hardware
29 acceleration of MPEG1/MPEG2 decoding (not available on the KM/N400)
30 that uses the Direct Rendering Infrastructure (DRI). The XvMC client
31 library implements a non-standard "VLD" extension to the XvMC standard.
32 The current Direct Rendering Manager (DRM) kernel module is available
33 at dri.sourceforge.net.
34 The driver supports free modes for Unichrome Pros (K8M800/K8N800,
36 PM800/PN800, and CN400). For plain Unichromes (CLE266, KM400/KN400),
37 it currently supports only a limited number of dotclocks, so if you are
38 using X modelines you must make sure that the dotclock is one of those
39 supported. Supported dotclocks on plain Unichromes are currently (in
40 MHz): 25.2, 25.312, 26.591, 31.5, 31.704, 32.663, 33.750, 35.5, 36.0,
41 39.822, 40.0, 41.164, 46.981, 49.5, 50.0, 56.3, 57.284, 64.995, 65.0,
42 65.028, 74.480, 75.0, 78.8, 81.613, 94.5, 108.0, 108.28, 122.0,
43 122.726, 135.0, 148.5, 155.8, 157.5, 161.793, 162.0, 175.5, 189.0,
44 202.5, 204.8, 218.3, 229.5. On top of this, bandwidth restrictions
45 apply for both Unichromes and Unichrome Pros.
46
48 Please refer to xorg.conf() for general configuration details. This
49 section only covers configuration details specific to this driver.
50 The following driver options are supported:
52 Option "AccelMethod" "string"
54 The driver supports "XAA" and "EXA" acceleration methods. The
55 default method is XAA, since EXA is still experimental. Con‐
56 trary to XAA, EXA implements acceleration for screen uploads and
57 downlads (if DRI is enabled) and for the Render/Composite exten‐
58 sion.
59 Option "ActiveDevice" "string"
61 Specifies the active device combination. Any string containing
62 "CRT", "LCD", "DFP", "TV" should be possible. "CRT" represents
63 anything that is connected to the VGA port, "LCD" and "DFP" are
64 for laptop panels (not TFT screens attached to the VGA port),
65 "TV" is self-explanatory. The default is to use what is
66 detected. The driver is currently unable to use LCD and TV
67 simultaneously, and will favour the LCD.
68 Option "AGPMem" "integer"
70 Sets the amount of AGP memory that is allocated at X server
71 startup. The allocated memory will be "integer" kB. This AGP
72 memory is used for the AGP command buffer (if the option
73 "EnableAGPDMA" is set to "true"), for DRI textures, and for the
74 EXA scratch area. The driver will allocate at least one system
75 page of AGP memory, or -- if the AGP command buffer is used --
76 at least 2 MB plus one system page. If there is no room for the
77 EXA scratch area in AGP space, it will be allocated from VRAM.
78 If there is no room for DRI textures, they will be allocated
79 from the DRI part of VRAM (see the option "MaxDRIMem"). The
80 default amount of AGP is 32768 kB. Note that the AGP aperture
81 set in the BIOS must be able to accomodate the amount of AGP
82 memory specified here. Otherwise no AGP memory will be avail‐
83 able. It is safe to set a very large AGP aperture in the BIOS.
84 Option "Center" "boolean"
86 Enables image centering on DVI displays. The default is dis‐
87 abled.
88 Option "DisableIRQ" "boolean"
90 Disables the vertical blank IRQ. This is a workaround for some
91 mainboards that have problems with IRQs coming from the
92 Unichrome engine. With IRQs disabled, DRI clients have no way
93 to synchronize their drawing to Vblank. (IRQ is disabled by
94 default on the KM400 and K8M800 chipsets.)
95 Option "DisableVQ" "boolean"
97 Disables the use of the virtual command queue. The queue is
98 enabled by default.
99 Option "EnableAGPDMA" "boolean"
101 Enables the AGP DMA functionality in DRM. This requires that
102 DRI is enabled and will force 2D and 3D acceleration to use AGP
103 DMA. The XvMC DRI client will also make use of this on the
104 CLE266 to consume much less CPU. (This option is enabled by
105 default, except on the K8M890 and P4M900.)
106 Option "ExaNoComposite" "boolean"
108 If EXA is enabled (using the option "AccelMethod"), this option
109 enables acceleration of compositing. Since EXA, and in particu‐
110 lar its composite acceleration, is still experimental, this is a
111 way to disable a misbehaving composite acceleration.
112 Option "ExaScratchSize" "integer"
114 Sets the size of the EXA scratch area to "integer" kB. This
115 area is used by EXA as a last place to look for available space
116 for pixmaps. Too little space will slow compositing down. This
117 option should be set to the size of the largest pixmap used. If
118 you have a screen width of over 1024 pixels and use 24 bpp, set
119 this to 8192. Otherwise you can leave this at the default 4096.
120 The space will be allocated from AGP memory if available, other‐
121 wise from VRAM.
122 Option "LCDDualEdge" "boolean"
124 Enables the use of dual-edge mode to set the LCD. The default
125 is disabled.
126 Option "MaxDRIMem" "integer"
128 Sets the maximum amount of VRAM memory allocated for DRI clients
129 to "integer" kB. Normally DRI clients get half the available
130 VRAM size, but in some cases it may make sense to limit this
131 amount. For example, if you are using a composite manager and
132 you want to give as much memory as possible to the EXA pixmap
133 storage area.
134 Option "MigrationHeuristic" "string"
136 Sets the heuristic for EXA pixmap migration. This is an EXA
137 core option, and on Xorg server versions after 1.1.0 this
138 defaults to "smart". The openchrome driver performs best with
139 "greedy", so you should really add this option to your configu‐
140 ration file. The third possibility is "always", which might
141 become more useful in the future.
142 Option "NoAccel" "boolean"
144 Disables the use of hardware acceleration. Acceleration is
145 enabled by default.
146 Option "NoAGPFor2D" "boolean"
148 Disables the use of AGP DMA for 2D acceleration, even when AGP
149 DMA is enabled. The default is enabled.
150 Option "NoXVDMA" "boolean"
152 If DRI is enabled, Xv normally uses PCI DMA to transfer video
153 images from system to frame-buffer memory. This is somewhat
154 slower than direct copies due to the limitations of the PCI bus,
155 but on the other hand it decreases CPU usage significantly, par‐
156 ticularly on computers with fast processors. Some video players
157 are buggy and will display rendering artifacts when PCI DMA is
158 used. If you experience this, or don't want your PCI bus to be
159 stressed with Xv images, set this option to "true". This option
160 has no effect when DRI is not enabled.
161 Option "PanelSize" "string"
163 Specifies the size (width x height) of the LCD panel attached to
164 the system. The sizes 640x480, 800x600, 1024x768, 1280x1024,
165 and 1400x1050 are supported.
166 Option "Rotate" "string"
168 Rotates the display either clockwise ("CW") or counterclockwise
169 ("CCW"). Rotation is only supported unaccelerated.
170 Option "ShadowFB" "boolean"
172 Enables the use of a shadow frame buffer. This is required when
173 rotating the display, but otherwise defaults to disabled.
174 Option "SWCursor" "boolean"
176 Enables the use of a software cursor. The default is disabled:
177 the hardware cursor is used.
178 Option "TVDeflicker" "integer"
180 Specifies the deflicker setting for TV output. Valid values are
181 "0", "1", and "2". Here 0 means no deflicker, 1 means 1:1:1
182 deflicker, and 2 means 1:2:1 deflicker.
183 Option "TVDotCrawl" "boolean"
185 Enables dot-crawl suppression. The default is disabled.
186 Option "TVOutput" "string"
188 Specifies which TV output to use. The driver supports "S-
189 Video", "Composite", "SC", "RGB", and "YCbCr" outputs. Note
190 that on some EPIA boards the composite-video port is shared with
191 audio-out and is selected via a jumper.
192 Option "TVType" "string"
194 Specifies TV output format. The driver currently supports
195 "NTSC" and "PAL" timings only.
196 Option "VBEModes" "boolean"
198 Enables the use of VBE BIOS calls for setting the display mode.
199 This mimics the behaviour of the vesa driver but still provides
200 acceleration and other features. This option may be used if
201 your hardware works with the vesa driver but not with the
202 openchrome driver. It may not work on 64-bit systems. Using
203 "VBEModes" may speed up driver acceleration significantly due to
204 a more aggressive hardware setting, particularly on systems with
205 low memory bandwidth. Your refresh rate may be limited to 60 Hz
206 on some systems.
207 Option "VBESaveRestore" "boolean"
209 Enables the use of VBE BIOS calls for saving and restoring the
210 display state when the X server is launched. This can be
211 extremely slow on some hardware, and the system may appear to
212 have locked for 10 seconds or so. The default is to use the
213 driver builtin function. This option only works if option "VBE‐
214 Modes" is enabled.
215 Option "VideoRAM" "integer"
217 Overrides the VideoRAM autodetection. This should never be
218 needed.
219
221 Unichromes tend to be paired with several different TV encoders.
222 VIA Technologies VT1621
224 Still untested, as no combination with a Unichrome is known or
225 available. Supports the following normal modes: "640x480" and
226 "800x600". Use "640x480Over" and "800x600Over" for vertical
227 overscan. These modes are made available by the driver; mode‐
228 lines provided in xorg.conf will be ignored.
229 VIA Technologies VT1622, VT1622A, VT1623
231 Supports the following modes: "640x480", "800x600", "1024x768",
232 "848x480", "720x480" (NTSC only) and "720x576" (PAL only). Use
233 "640x480Over", "800x600Over", "1024x768Over", "848x480Over",
234 "720x480Over" (NTSC) and "720x576Over" (PAL) for vertical over‐
235 scan. The modes "720x480Noscale" (NTSC) and "720x576Noscale"
236 (PAL) (available on VT1622 only) provide cleaner TV output
237 (unscaled with only minimal overscan). These modes are made
238 available by the driver; modelines provided in xorg.conf will be
239 ignored.
240
243 Xorg(), xorg.conf(), xorgconfig(), Xserver(), X()
244
246 Authors include: ...
247X Version 11 xf86-video-openchrome 0.2.902 OPENCHROME(4)