1s3(4) Kernel Interfaces Manual s3(4)
2
6 s3 - S3 video driver
7
9 Section "Device"
10 Identifier "devname"
11 Driver "s3"
12 ...
13 [Option "optionname" ["optionvalue"]]
14 EndSection
15
18 The s3 driver supports PCI video cards based on the following S3 chips:
19 Trio32 86C732
21 Trio64 86C764
23 Trio64V+ 86C765
25 Aurora64V+ 86CM65
27 Trio64UV+ 86C767
29 Trio64V2/DX 86C775
31 Trio64V2/GX 86C785
33 Vision964 86C964
35 Vision968 86C968
37 Also driver supports the following RAMDACs:
40 IBM 524, IBM 524A, IBM 526, IBM 526DB
42 TI ViewPoint 3025
44
47 s3 is an Xorg driver for S3 based video cards. The driver provides full
48 accelerated support for the following colour depths: 8, 15, 16 and 24.
49 The overlay video (Xv) is supported in depths 16 and 24 for the
50 Trio64V+, Trio64UV+, Trio64V2/DX and Trio64V2/GX chips.
51
54 Please refer to xorg.conf(5) for general configuration details. This
55 section only covers configuration details specific to this driver. All
56 options names are case and white space insensitive when parsed by the
57 server, for example, "trio 32/64" and "Trio32/64" are equivalent.
58 Chip overriding
61 The driver auto-detects the chipset and RAMDAC, but the following
62 Chipset names may optionally be specified in the configuration file
63 "Device" section, and will override the auto-detection:
64 "964-0", "964-1" 86C964 (rev.0 and rev.1)
67 "968" 86C968
69 "Trio32/64" 86C732/86C764
71 "Aurora64V+" 86CM65
73 "Trio64UV+" 86C767
75 "Trio64V2/DX/GX" 86C775/86C785
77 The 86C765 (Trio64V+) is Chipset "Trio32/64" with ChipRev greater or
80 equal 0x40.
81 An overriding of RAMDAC auto-detection currently is not implemented.
83 Colour depth
86 For every supported colour depth the X server automatically selects an
87 appropriate number of bits per pixel (bpp) for framebuffer. The depth 8
88 is represented by 8 bpp framebuffer (1 byte/pixel), the depths 15 and
89 16 (respectively 5.5.5 and 5.6.5 pixel formats) are represented by the
90 16 bpp framebuffer (2 bytes/pixel). Whenever the depth 24 is config‐
91 ured, the X server by default uses the 32 bpp framebuffer (4
92 bytes/pixel), and the hardware is adjusted accordingly to the X.8.8.8
93 pixel format, where X is the ignored upper byte.
94 As the second option for the depth 24, the X server can be configured
97 to use 24 bpp framebuffer with the 8.8.8 pixel format (3 bytes/pixel),
98 which is supported by Trio64V+, Trio64UV+, Trio64V2/DX and Trio64V2/GX.
99 If the video board has limited video RAM the 24 bpp framebuffer has an
100 advantage over 32 bpp framebuffer as it requires less memory to store
101 screen, and, therefore, more space will be available for a video frame
102 (see "Overlay video" section). The 24 bpp framebuffer can be selected
103 by X server's option -fbbpp 24 or by specifying DefaultFbBpp option in
104 xorg.conf(5):
105 Section "Screen"
107 DefaultFbBpp 24
108 DefaultDepth 24
109 ...
110 EndSection
111 However, the 24 bpp framebuffer mode has the hardware limitations: (i)
114 the 2D acceleration doesn't work with this mode (use the "shadowFB"
115 option to speed up drawing routines in this case); (ii) 24 bpp frame‐
116 buffer cannot be used with either interlaced or doublescan graphics
117 modes.
118 Overlay video
121 If your video board has limited RAM it would be useful to estimate how
122 large video frame might be placed in offscreen video memory. Suppose
123 that the video board has 2 MB of RAM, and X server is configured to
124 display 800x600 with the depth 24. By default the 32 bpp framebuffer
125 will be chosen for this depth, so 800 x 600 x 4 = 1875 kB will be
126 reserved for screen, and 2 MB - 1875 kB = 173 kB will remain for the
127 offscreen area. This is sufficient space, for example, for the VCD NTSC
128 352x240 frame. If you need to upscale video with a bigger frame, but it
129 doesn't fit the offscreen area, the only way to do this is to lower
130 either the resolution or framebuffer's depth or both before the view‐
131 ing, otherwise, you will get the allocation error and will not see the
132 video. For example, with 24 bpp framebuffer and the same resolution
133 800x600 the offscreen area will be about 640 kB - it's enough for the
134 640x480 frame. 800x600 with the 16 bpp framebuffer gives about 1110 kB
135 of offscreen area - this allows to upscale up to 768x576 movies. Note,
136 that all movie resolutions in examples above are provided as a refer‐
137 ence; the movies can have the different aspect ratios and non-standard
138 dimensions. A total pixel amount is the main consideration not the cer‐
139 tain width and height.
140 Due to hardware limitation the overlay video will not work with the
142 interlaced/doublescan modes. Downscaling is not implemented in hard‐
143 ware.
144 Configuration options
147 The following display Options are supported:
148 Option "HWCursor" "boolean"
150 Enable or disable the hardware cursor. Currently, hardware cur‐
151 sor is not implemented, so the option will be ignored. Default:
152 off (software cursor).
153 Option "NoAccel" "boolean"
155 Disable acceleration. Very useful for determining if the driver
156 has problems with drawing and acceleration routines. This is the
157 first option to try if your server runs but you see graphic cor‐
158 ruption on the screen. Using it decreases performance, as it
159 uses software emulation for drawing operations the video driver
160 can accelerate with hardware. Default: off (acceleration is
161 enabled).
162 Option "ShadowFB" "boolean"
164 Use shadow framebuffer. Disables hardware acceleration. Use this
165 option when the hardware acceleration is not available or unde‐
166 sirable. Default: off.
167 Option "XVideo" "boolean"
169 Enable or disable Xv support. Default: on.
170 The following video memory Options are supported:
173 Option "slow_dram_refresh" "boolean"
175 Enable three refresh cycles per scanline. Default: off (one
176 refresh cycle).
177 Option "slow_edodram" "boolean"
179 Switch to 2-cycle EDO mode. Try this if you encounter pixel cor‐
180 ruption. Using this option will cause a decrease in performance.
181 Default: off (BIOS defaults).
182 Option "slow_dram" "boolean"
184 For Trio and Aurora64V+ chips: increase -RAS Precharge Timing to
185 3.5 MCLK. Try this option if you encounter pixel errors.
186 Default: off (BIOS defaults).
187 Option "slow_vram" "boolean"
189 For Vision964, Vision968 chips: increase -RAS Low Timing to 4.5
190 MCLK. Default: off (BIOS defaults).
191
194 Xorg(1), xorg.conf(5), Xserver(1), X(7)
195
198 Thomas Roell, Mark Vojkovich, Kevin E. Martin, Amancio Hasty, Jon N.
199 Tombs and others were the original authors of driver for XFree86 3.x.
200 Ani Joshi reworked driver for XFree86 4.x. The further modifications
201 were made by the following contributors: Adam Jackson, Alan Cooper‐
202 smith, Dave Airlie, Andrew Radrianasulu, Paulo Cesar Pereira de
203 Andrade, Eric Anholt, Søren Sandmann Pedersen, Alex Deucher, Evgeny M.
204 Zubok, Daniel Stone and others.
205 The manual was written by Evgeny M. Zubok <evgeny.zubok@tochka.ru>
208X Version 11 xf86-video-s3 0.6.3 s3(4)