Documentation/fb/intel810.txt

   1 Intel 810/815 Framebuffer driver
   2         Tony Daplas <adaplas@pol.net>
   3         http://i810fb.sourceforge.net
   4
   5         March 17, 2002
   6
   7         First Released: July 2001
   8         Last Update:    September 12, 2005
   9 ================================================================
  10
  11 A. Introduction
  12         This is a framebuffer driver for various Intel 810/815 compatible
  13 graphics devices.  These would include:
  14
  15         Intel 810
  16         Intel 810E
  17         Intel 810-DC100
  18         Intel 815 Internal graphics only, 100Mhz FSB
  19         Intel 815 Internal graphics only
  20         Intel 815 Internal graphics and AGP
  21
  22 B.  Features
  23
  24         - Choice of using Discrete Video Timings, VESA Generalized Timing
  25           Formula, or a framebuffer specific database to set the video mode
  26
  27         - Supports a variable range of horizontal and vertical resolution, and
  28           vertical refresh rates if the VESA Generalized Timing Formula is
  29           enabled.
  30
  31         - Supports color depths of 8, 16, 24 and 32 bits per pixel
  32
  33         - Supports pseudocolor, directcolor, or truecolor visuals
  34
  35         - Full and optimized hardware acceleration at 8, 16 and 24 bpp
  36
  37         - Robust video state save and restore
  38
  39         - MTRR support
  40
  41         - Utilizes user-entered monitor specifications to automatically
  42           calculate required video mode parameters.
  43
  44         - Can concurrently run with xfree86 running with native i810 drivers
  45
  46         - Hardware Cursor Support
  47
  48         - Supports EDID probing either by DDC/I2C or through the BIOS
  49
  50 C.  List of available options
  51
  52    a. "video=i810fb"
  53         enables the i810 driver
  54
  55         Recommendation: required
  56
  57    b. "xres:<value>"
  58         select horizontal resolution in pixels. (This parameter will be
  59         ignored if 'mode_option' is specified.  See 'o' below).
  60
  61         Recommendation: user preference
  62         (default = 640)
  63
  64    c. "yres:<value>"
  65         select vertical resolution in scanlines. If Discrete Video Timings
  66         is enabled, this will be ignored and computed as 3*xres/4.  (This
  67         parameter will be ignored if 'mode_option' is specified.  See 'o'
  68         below)
  69
  70         Recommendation: user preference
  71         (default = 480)
  72
  73    d. "vyres:<value>"
  74         select virtual vertical resolution in scanlines. If (0) or none
  75         is specified, this will be computed against maximum available memory.
  76
  77         Recommendation: do not set
  78         (default = 480)
  79
  80    e. "vram:<value>"
  81         select amount of system RAM in MB to allocate for the video memory
  82
  83         Recommendation: 1 - 4 MB.
  84         (default = 4)
  85
  86    f. "bpp:<value>"
  87         select desired pixel depth
  88
  89         Recommendation: 8
  90         (default = 8)
  91
  92    g. "hsync1/hsync2:<value>"
  93         select the minimum and maximum Horizontal Sync Frequency of the
  94         monitor in KHz.  If a using a fixed frequency monitor, hsync1 must
  95         be equal to hsync2. If EDID probing is successful, these will be
  96         ignored and values will be taken from the EDID block.
  97
  98         Recommendation: check monitor manual for correct values
  99         default (29/30)
 100
 101    h. "vsync1/vsync2:<value>"
 102         select the minimum and maximum Vertical Sync Frequency of the monitor
 103         in Hz. You can also use this option to lock your monitor's refresh
 104         rate. If EDID probing is successful, these will be ignored and values
 105         will be taken from the EDID block.
 106
 107         Recommendation: check monitor manual for correct values
 108         (default = 60/60)
 109
 110         IMPORTANT:  If you need to clamp your timings, try to give some
 111         leeway for computational errors (over/underflows).  Example: if
 112         using vsync1/vsync2 = 60/60, make sure hsync1/hsync2 has at least
 113         a 1 unit difference, and vice versa.
 114
 115    i. "voffset:<value>"
 116         select at what offset in MB of the logical memory to allocate the
 117         framebuffer memory.  The intent is to avoid the memory blocks
 118         used by standard graphics applications (XFree86).  The default
 119         offset (16 MB for a 64MB aperture, 8 MB for a 32MB aperture) will
 120         avoid XFree86's usage and allows up to 7MB/15MB of framebuffer
 121         memory.  Depending on your usage, adjust the value up or down,
 122         (0 for maximum usage, 31/63 MB for the least amount).  Note, an
 123         arbitrary setting may conflict with XFree86.
 124
 125         Recommendation: do not set
 126         (default = 8 or 16 MB)
 127
 128    j. "accel"
 129         enable text acceleration.  This can be enabled/reenabled anytime
 130         by using 'fbset -accel true/false'.
 131
 132         Recommendation: enable
 133         (default = not set)
 134
 135    k. "mtrr"
 136         enable MTRR.  This allows data transfers to the framebuffer memory
 137         to occur in bursts which can significantly increase performance.
 138         Not very helpful with the i810/i815 because of 'shared memory'.
 139
 140         Recommendation: do not set
 141         (default = not set)
 142
 143    l. "extvga"
 144         if specified, secondary/external VGA output will always be enabled.
 145         Useful if the BIOS turns off the VGA port when no monitor is attached.
 146         The external VGA monitor can then be attached without rebooting.
 147
 148         Recommendation: do not set
 149         (default = not set)
 150
 151    m. "sync"
 152         Forces the hardware engine to do a "sync" or wait for the hardware
 153         to finish before starting another instruction. This will produce a
 154         more stable setup, but will be slower.
 155
 156         Recommendation: do not set
 157         (default = not set)
 158
 159    n. "dcolor"
 160         Use directcolor visual instead of truecolor for pixel depths greater
 161         than 8 bpp.  Useful for color tuning, such as gamma control.
 162
 163         Recommendation: do not set
 164         (default = not set)
 165    o. <xres>x<yres>[-<bpp>][@<refresh>]
 166         The driver will now accept specification of boot mode option.  If this
 167         is specified, the options 'xres' and 'yres' will be ignored. See
 168         Documentation/fb/modedb.txt for usage.
 169
 170 D. Kernel booting
 171
 172 Separate each option/option-pair by commas (,) and the option from its value
 173 with a colon (:) as in the following:
 174
 175 video=i810fb:option1,option2:value2
 176
 177 Sample Usage
 178 ------------
 179
 180 In /etc/lilo.conf, add the line:
 181
 182 append="video=i810fb:vram:2,xres:1024,yres:768,bpp:8,hsync1:30,hsync2:55, \
 183         vsync1:50,vsync2:85,accel,mtrr"
 184
 185 This will initialize the framebuffer to 1024x768 at 8bpp.  The framebuffer
 186 will use 2 MB of System RAM. MTRR support will be enabled. The refresh rate
 187 will be computed based on the hsync1/hsync2 and vsync1/vsync2 values.
 188
 189 IMPORTANT:
 190 You must include hsync1, hsync2, vsync1 and vsync2 to enable video modes
 191 better than 640x480 at 60Hz. HOWEVER, if your chipset/display combination
 192 supports I2C and has an EDID block, you can safely exclude hsync1, hsync2,
 193 vsync1 and vsync2 parameters.  These parameters will be taken from the EDID
 194 block.
 195
 196 E.  Module options
 197
 198         The module parameters are essentially similar to the kernel
 199 parameters. The main difference is that you need to include a Boolean value
 200 (1 for TRUE, and 0 for FALSE) for those options which don't need a value.
 201
 202 Example, to enable MTRR, include "mtrr=1".
 203
 204 Sample Usage
 205 ------------
 206
 207 Using the same setup as described above, load the module like this:
 208
 209         modprobe i810fb vram=2 xres=1024 bpp=8 hsync1=30 hsync2=55 vsync1=50 \
 210                  vsync2=85 accel=1 mtrr=1
 211
 212 Or just add the following to /etc/modprobe.conf
 213
 214         options i810fb vram=2 xres=1024 bpp=16 hsync1=30 hsync2=55 vsync1=50 \
 215         vsync2=85 accel=1 mtrr=1
 216
 217 and just do a
 218
 219         modprobe i810fb
 220
 221
 222 F.  Setup
 223
 224         a. Do your usual method of configuring the kernel.
 225
 226         make menuconfig/xconfig/config
 227
 228         b. Under "Code Maturity Options", enable "Prompt for experimental/
 229            incomplete code/drivers".
 230
 231         c. Enable agpgart support for the Intel 810/815 on-board graphics.
 232            This is required.  The option is under "Character Devices"
 233
 234         d. Under "Graphics Support", select "Intel 810/815" either statically
 235            or as a module.  Choose "use VESA Generalized Timing Formula" if
 236            you need to maximize the capability of your display.  To be on the
 237            safe side, you can leave this unselected.
 238
 239         e. If you want support for DDC/I2C probing (Plug and Play Displays),
 240            set 'Enable DDC Support' to 'y'. To make this option appear, set
 241            'use VESA Generalized Timing Formula' to 'y'.
 242
 243         f. If you want a framebuffer console, enable it under "Console
 244            Drivers"
 245
 246         g. Compile your kernel.
 247
 248         h. Load the driver as described in section D and E.
 249
 250         i.  Try the DirectFB (http://www.directfb.org) + the i810 gfxdriver
 251             patch to see the chipset in action (or inaction :-).
 252
 253 G.  Acknowledgment:
 254
 255         1.  Geert Uytterhoeven - his excellent howto and the virtual
 256                                  framebuffer driver code made this possible.
 257
 258         2.  Jeff Hartmann for his agpgart code.
 259
 260         3.  The X developers.  Insights were provided just by reading the
 261             XFree86 source code.
 262
 263         4.  Intel(c).  For this value-oriented chipset driver and for
 264             providing documentation.
 265
 266         5. Matt Sottek.  His inputs and ideas  helped in making some
 267         optimizations possible.
 268
 269 H.  Home Page:
 270
 271         A more complete, and probably updated information is provided at
 272 http://i810fb.sourceforge.net.
 273
 274 ###########################
 275 Tony
 276