1OPENCHROME(4) Kernel Interfaces Manual OPENCHROME(4)
2
6 openchrome - video driver for VIA Unichromes
7
9 Section "Device"
10 Identifier "devname"
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/KM400A/P4M800, CN400/PM800/PN800/PM880, K8M800,
22 CN700/VM800/P4M800Pro, CX700, P4M890, K8M890, P4M900/VN896/CN896,
23 VX800, VX855 and VX900. The driver includes 2D acceleration and Xv
24 video overlay extensions. Flat panel, TV, and VGA outputs are sup‐
25 ported, depending on the hardware configuration.
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(5) 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 downloads (if DRI is enabled) and for the Render/Composite
58 extension.
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" is for laptop
64 panels (not TFT screens attached to the VGA port), "DFP" is for
65 screens connected to the DVI port, "TV" is self-explanatory.
66 The default is to use what is detected. The driver is currently
67 unable to use LCD and TV simultaneously, and will favour the
68 LCD. The DVI port is not properly probed and needs to be
69 enabled with this option.
70 Option "AGPMem" "integer"
72 Sets the amount of AGP memory that is allocated at X server
73 startup. The allocated memory will be "integer" kB. This AGP
74 memory is used for the AGP command buffer (if the option
75 "EnableAGPDMA" is set to "true"), for DRI textures, and for the
76 EXA scratch area. The driver will allocate at least one system
77 page of AGP memory, or -- if the AGP command buffer is used --
78 at least 2 MB plus one system page. If there is no room for the
79 EXA scratch area in AGP space, it will be allocated from VRAM.
80 If there is no room for DRI textures, they will be allocated
81 from the DRI part of VRAM (see the option "MaxDRIMem"). The
82 default amount of AGP is 32768 kB. Note that the AGP aperture
83 set in the BIOS must be able to accommodate the amount of AGP
84 memory specified here. Otherwise no AGP memory will be avail‐
85 able. It is safe to set a very large AGP aperture in the BIOS.
86 Option "Center" "boolean"
88 Enables image centering on DVI displays. The default is dis‐
89 abled.
90 Option "DisableIRQ" "boolean"
92 Disables the vertical blank IRQ. This is a workaround for some
93 mainboards that have problems with IRQs coming from the
94 Unichrome engine. With IRQs disabled, DRI clients have no way
95 to synchronize their drawing to Vblank. (IRQ is disabled by
96 default on the KM400 and K8M800 chipsets.)
97 Option "DisableVQ" "boolean"
99 Disables the use of the virtual command queue. The queue is
100 enabled by default.
101 Option "EnableAGPDMA" "boolean"
103 Enables the AGP DMA functionality in DRM. This requires that
104 DRI is enabled and will force 2D and 3D acceleration to use AGP
105 DMA. The XvMC DRI client will also make use of this on the
106 CLE266 to consume much less CPU. (This option is enabled by
107 default, except on the K8M890 and P4M900.)
108 Option "ExaNoComposite" "boolean"
110 If EXA is enabled (using the option "AccelMethod"), this option
111 enables acceleration of compositing. Since EXA, and in particu‐
112 lar its composite acceleration, is still experimental, this is a
113 way to disable a misbehaving composite acceleration.
114 Option "ExaScratchSize" "integer"
116 Sets the size of the EXA scratch area to "integer" kB. This
117 area is used by EXA as a last place to look for available space
118 for pixmaps. Too little space will slow compositing down. This
119 option should be set to the size of the largest pixmap used. If
120 you have a screen width of over 1024 pixels and use 24 bpp, set
121 this to 8192. Otherwise you can leave this at the default 4096.
122 The space will be allocated from AGP memory if available, other‐
123 wise from VRAM.
124 Option "LCDDualEdge" "boolean"
126 Enables the use of dual-edge mode to set the LCD. The default
127 is disabled.
128 Option "MaxDRIMem" "integer"
130 Sets the maximum amount of VRAM memory allocated for DRI clients
131 to "integer" kB. Normally DRI clients get half the available
132 VRAM size, but in some cases it may make sense to limit this
133 amount. For example, if you are using a composite manager and
134 you want to give as much memory as possible to the EXA pixmap
135 storage area.
136 Option "MigrationHeuristic" "string"
138 Sets the heuristic for EXA pixmap migration. This is an EXA
139 core option, and starting from Xorg server version 1.3.0 this
140 defaults to "always". The openchrome driver performs best with
141 "greedy", so you should really add this option to your configu‐
142 ration file. The third possibility is "smart".
143 Option "NoAccel" "boolean"
145 Disables the use of hardware acceleration. Acceleration is
146 enabled by default.
147 Option "NoAGPFor2D" "boolean"
149 Disables the use of AGP DMA for 2D acceleration, even when AGP
150 DMA is enabled. The default is enabled.
151 Option "NoXVDMA" "boolean"
153 If DRI is enabled, Xv normally uses PCI DMA to transfer video
154 images from system to frame-buffer memory. This is somewhat
155 slower than direct copies due to the limitations of the PCI bus,
156 but on the other hand it decreases CPU usage significantly, par‐
157 ticularly on computers with fast processors. Some video players
158 are buggy and will display rendering artifacts when PCI DMA is
159 used. If you experience this, or don't want your PCI bus to be
160 stressed with Xv images, set this option to "true". This option
161 has no effect when DRI is not enabled.
162 Option "PanelSize" "string"
164 Specifies the size (width x height) of the LCD panel attached to
165 the system. The sizes 640x480, 800x600, 1024x768, 1280x1024,
166 and 1400x1050 are supported.
167 Option "RotationType" "string"
169 Enabled rotation by using RandR. The driver only support unac‐
170 celerated RandR rotations "SWRandR". Hardware rotations
171 "HWRandR" is currently unimplemented.
172 Option "Rotate" "string"
174 Rotates the display either clockwise ("CW"), counterclockwise
175 ("CCW") and upside-down ("UD"). Rotation is only supported unac‐
176 celerated. Adding option "Rotate", enables RandR rotation fea‐
177 ture. The RandR allows clients to dynamically change X screens.
178 Option "ShadowFB" "boolean"
180 Enables the use of a shadow frame buffer. This is required when
181 rotating the display, but otherwise defaults to disabled.
182 Option "SWCursor" "boolean"
184 Enables the use of a software cursor. The default is disabled:
185 the hardware cursor is used.
186 Option "TVDeflicker" "integer"
188 Specifies the deflicker setting for TV output. Valid values are
189 "0", "1", and "2". Here 0 means no deflicker, 1 means 1:1:1
190 deflicker, and 2 means 1:2:1 deflicker.
191 Option "TVDotCrawl" "boolean"
193 Enables dot-crawl suppression. The default is disabled.
194 Option "TVOutput" "string"
196 Specifies which TV output to use. The driver supports "S-
197 Video", "Composite", "SC", "RGB", and "YCbCr" outputs. Note
198 that on some EPIA boards the composite-video port is shared with
199 audio-out and is selected via a jumper.
200 Option "TVPort" "string"
202 Specifies TV port. The driver currently supports "DVP0",
203 "DVP1", "DFPHigh" and "DFPLow" ports.
204 Option "TVType" "string"
206 Specifies TV output format. The driver currently supports
207 "NTSC" and "PAL" timings only.
208 Option "VBEModes" "boolean"
210 Enables the use of VBE BIOS calls for setting the display mode.
211 This mimics the behaviour of the vesa driver but still provides
212 acceleration and other features. This option may be used if
213 your hardware works with the vesa driver but not with the
214 openchrome driver. It may not work on 64-bit systems. Using
215 "VBEModes" may speed up driver acceleration significantly due to
216 a more aggressive hardware setting, particularly on systems with
217 low memory bandwidth. Your refresh rate may be limited to 60 Hz
218 on some systems.
219 Option "VBESaveRestore" "boolean"
221 Enables the use of VBE BIOS calls for saving and restoring the
222 display state when the X server is launched. This can be
223 extremely slow on some hardware, and the system may appear to
224 have locked for 10 seconds or so. The default is to use the
225 driver builtin function. This option only works if option "VBE‐
226 Modes" is enabled.
227 Option "VideoRAM" "integer"
229 Overrides the VideoRAM autodetection. This should never be
230 needed.
231
233 Unichromes tend to be paired with several different TV encoders.
234 VIA Technologies VT1621
236 Still untested, as no combination with a Unichrome is known or
237 available. Supports the following normal modes: "640x480" and
238 "800x600". Use "640x480Over" and "800x600Over" for vertical
239 overscan. These modes are made available by the driver; mode‐
240 lines provided in xorg.conf will be ignored.
241 VIA Technologies VT1622, VT1622A, VT1623
243 Supports the following modes: "640x480", "800x600", "1024x768",
244 "848x480", "720x480" (NTSC only) and "720x576" (PAL only). Use
245 "640x480Over", "800x600Over", "1024x768Over", "848x480Over",
246 "720x480Over" (NTSC) and "720x576Over" (PAL) for vertical over‐
247 scan. The modes "720x480Noscale" (NTSC) and "720x576Noscale"
248 (PAL) (available on VT1622 only) provide cleaner TV output
249 (unscaled with only minimal overscan). These modes are made
250 available by the driver; modelines provided in xorg.conf will be
251 ignored.
252
255 Xorg(1), xorg.conf(5), Xserver(1), X(7), EXA(5), Xv(5)
256
258 Authors include: ...
259X Version 11 xf86-video-openchrome 0.3.3 OPENCHROME(4)