[This file is cloned from VesaFB. Thanks go to Gerd Knorr] What is matroxfb? ================= This is a driver for a graphic framebuffer for Matrox devices on Alpha, Intel and PPC boxes. Advantages: * It provides a nice large console (128 cols + 48 lines with 1024x768) without using tiny, unreadable fonts. * You can run XF68_FBDev on top of /dev/fb0 * Most important: boot logo :-) Disadvantages: * graphic mode is slower than text mode... but you should not notice if you use same resolution as you used in textmode. How to use it? ============== Switching modes is done using the video=matrox:vesa:... boot parameter or using `fbset' program. If you want, for example, enable a resolution of 1280x1024x24bpp you should pass to the kernel this command line: "video=matrox:vesa:0x1BB". Note that the same line, if 'appended' as a lilo parameter in lilo.conf will read "video=matrox:vesa:443" because lilo pass integer parameters as decimal numbers to the kernel. You should compile in both vgacon (to boot if you remove you Matrox from box) and matroxfb (for graphics mode). You should not compile-in vesafb unless you have primary display on non-Matrox VBE2.0 device (see Documentation/vesafb.txt for details). Currently supported video modes are (through vesa:... interface, PowerMac has [as addon] compatibility code): [Graphic modes] bpp | 640x400 640x480 768x576 800x600 960x720 ----+-------------------------------------------- 4 | 0x12 0x102 8 | 0x100 0x101 0x180 0x103 0x188 15 | 0x110 0x181 0x113 0x189 16 | 0x111 0x182 0x114 0x18A 24 | 0x1B2 0x184 0x1B5 0x18C 32 | 0x112 0x183 0x115 0x18B [Graphic modes (continued)] bpp | 1024x768 1152x864 1280x1024 1408x1056 1600x1200 ----+------------------------------------------------ 4 | 0x104 0x106 8 | 0x105 0x190 0x107 0x198 0x11C 15 | 0x116 0x191 0x119 0x199 0x11D 16 | 0x117 0x192 0x11A 0x19A 0x11E 24 | 0x1B8 0x194 0x1BB 0x19C 0x1BF 32 | 0x118 0x193 0x11B 0x19B [Text modes] text | 640x400 640x480 1056x344 1056x400 1056x480 -----+------------------------------------------------ 8x8 | 0x1C0 0x108 0x10A 0x10B 0x10C 8x16 | 2, 3, 7 0x109 You can enter these number either hexadecimal (leading `0x') or decimal (0x100 = 256). You can also use value + 512 to achieve compatibility with your old number passed to vesafb. Non-listed number can be achieved by more complicated command-line, for example 1600x1200x32bpp can be specified by `video=matrox:vesa:0x11C,depth:32'. X11 === XF68_FBDev should work just fine, but it is non-accelerated. On non-intel architectures there are some glitches for 24bpp videomodes. 8, 16 and 32bpp works fine. Running another (accelerated) X-Server like XF86_SVGA works too. But (at least) XFree servers have big troubles in multihead configurations (even on first head, not even talking about second). SVGALib ======= Driver contains SVGALib compatibility code. It is turned on by choosing textual mode for console. You can do it at boot time by using videomode 2,3,7,0x108-0x10C or 0x1C0. At runtime, `fbset -depth 0' does this work. Unfortunately, after SVGALib application exits, screen contents is corrupted. Switching to another console and back fixes it. I hope that it is SVGALib's problem and not mine, but I'm not sure. Configuration ============= You can pass kernel command line options to vesafb with `video=matrox:option1,option2:value2,option3' (multiple options should be separated by comma, values are separated from options by `:'). Accepted options: mem:X - size of memory (X can be in megabytes, kilobytes or bytes) You can only decrease value determined by driver because of it always probe for memory. Default is to use whole detected memory usable for on-screen display (i.e. max. 8 MB). disabled - do not load driver; you can use also `off', but `disabled' is here too. enabled - load driver, if you have `video=matrox:disabled' in LILO configuration, you can override it by this (you cannot override `off'). It is default. noaccel - do not use acceleration engine. It does not work on Alphas. accel - use acceleration engine. It is default. nopan - create initial consoles with vyres = yres, thus disabling virtual scrolling. pan - create initial consoles as tall as possible (vyres = memory/vxres). It is default. nopciretry - disable PCI retries. It is needed for some broken chipsets, it is autodetected for intel's 82437. In this case device does not comply to PCI 2.1 specs (it will not guarantee that every transaction terminate with success or retry in 32 PCLK). pciretry - enable PCI retries. It is default, except for intel's 82437. novga - disables VGA I/O ports. It is default if BIOS did not enable device. You should not use this option, some boards then do not restart without power off. vga - preserve state of VGA I/O ports. It is default. Driver does not enable VGA I/O if BIOS did not it (it is not safe to enable it in most cases). nobios - disables BIOS ROM. It is default if BIOS did not enable BIOS itself. You should not use this option, some boards then do not restart without power off. bios - preserve state of BIOS ROM. It is default. Driver does not enable BIOS if BIOS was not enabled before. noinit - tells driver, that devices were already initialized. You should use it if you have G100 and/or if driver cannot detect memory, you see strange pattern on screen and so on. Devices not enabled by BIOS are still initialized. It is default. init - driver initializes every device it knows about. nomtrr - disables write combining on frame buffer. This slows down driver but there is reported minor incompatibility between GUS DMA and XFree under high loads if write combining is enabled (sound dropouts). mtrr - enables write combining on frame buffer. It speeds up video accesses much. It is default. You must have MTRR support enabled in kernel and your CPU must have MTRR (f.e. Pentium II have them). sgram - tells to driver that you have G200 with SGRAM memory. It has no effect without `init'. sdram - tells to driver that you have G200 with SDRAM memory. It is a default. inv24 - change timings parameters for 24bpp modes on Millenium and Millenium II. Specify this if you see strange color shadows around characters. noinv24 - use standard timings. It is the default. inverse - invert colors on screen (for LCD displays) noinverse - show true colors on screen. It is default. dev:X - bind driver to device X. Driver numbers device from 0 up to N, where device 0 is first `known' device found, 1 second and so on. lspci lists devices in this order. Default is `every' known device for driver with multihead support and first working device (usually dev:0) for driver without multihead support. nohwcursor - disables hardware cursor (use software cursor instead). hwcursor - enables hardware cursor. It is default. If you are using non-accelerated mode (`noaccel' or `fbset -accel false'), software cursor is used (except for text mode). noblink - disables cursor blinking. Cursor in text mode always blinks (hw limitation). blink - enables cursor blinking. It is default. nofastfont - disables fastfont feature. It is default. fastfont:X - enables fastfont feature. X specifies size of memory reserved for font data, it must be >= (fontwidth*fontheight*chars_in_font)/8. It is faster on Gx00 series, but slower on older cards. grayscale - enable grayscale summing. It works in PSEUDOCOLOR modes (text, 4bpp, 8bpp). In DIRECTCOLOR modes it is limited to characters displayed through putc/putcs. Direct accesses to framebuffer can paint colors. nograyscale - disable grayscale summing. It is default. cross4MB - enables that pixel line can cross 4MB boundary. It is default for non-Millenium. nocross4MB - pixel line must not cross 4MB boundary. It is default for Millenium I or II, because of these devices have hardware limitations which do not allow this. But this option is incompatible with some (if not all yet released) versions of XF86_FBDev. vesa:X - selects startup videomode. X is number from 0 to 0x1FF, see table above for detailed explanation. Default is 640x480x8bpp if driver has 8bpp support. Otherwise first available of 640x350x4bpp, 640x480x15bpp, 640x480x24bpp, 640x480x32bpp or 80x25 text (80x25 text is always available). If you are not satisfied with videomode selected by `vesa' option, you can modify it with these options: xres:X - horizontal resolution, in pixels. Default is derived from `vesa' option. yres:X - vertical resolution, in pixel lines. Default is derived from `vesa' option. upper:X - top boundary: lines between end of VSYNC pulse and start of first pixel line of picture. Default is derived from `vesa' option. lower:X - bottom boundary: lines between end of picture and start of VSYNC pulse. Default is derived from `vesa' option. vslen:X - length of VSYNC pulse, in lines. Default is derived from `vesa' option. left:X - left boundary: pixels between end of HSYNC pulse and first pixel. Default is derived from `vesa' option. right:X - right boundary: pixels between end of picture and start of HSYNC pulse. Default is derived from `vesa' option. hslen:X - length of HSYNC pulse, in pixels. Default is derived from `vesa' option. pixclock:X - dotclocks, in ps (picoseconds). Default is derived from `vesa' option and from `fh' and `fv' options. sync:X - sync. pulse - bit 0 inverts HSYNC polarity, bit 1 VSYNC polarity. If bit 3 (value 0x08) is set, composite sync instead of HSYNC is generated. If bit 5 (value 0x20) is set, sync on green is turned on. Do not forget that if you want sync on green, you also probably want composite sync. Default depends on `vesa'. depth:X - Bits per pixel: 0=text, 4,8,15,16,24 or 32. Default depends on `vesa'. If you know capabilities of your monitor, you can specify some (or all) of `pixclk', `fh' and `fv'. In this case, `pixclock' is computed so that pixclock <= maxclk, real_fh <= fh and real_fv <= fv. maxclk:X - maximum dotclock. X can be specified in MHz, kHz or Hz. Default is `don't care'. fh:X - maximum horizontal synchronization frequency. X can be specified in kHz or Hz. Default is `don't care'. fv:X - maximum vertical frequency. X must be specified in Hz. Default is 70 for modes derived from `vesa' with yres <= 400, 60Hz for yres > 400. Limitations =========== There are known and unknown bugs, features and misfeatures. Currently there are following known bugs: + SVGALib does not restore screen on exit + generic fbcon-cfbX procedures do not work on Alphas. Due to this, `noaccel' (and cfb4 accel) driver does not work on Alpha. So everyone with access to /dev/fb* on Alpha can hang machine (you should restrict access to /dev/fb* - everyone with access to this device can destroy your monitor, believe me...). + 24bpp does not support correctly XF-FBDev on big-endian architectures. + interlaced text mode is not supported; it looks like hardware limitation, but I'm not sure. + G200 SGRAM/SDRAM is not autodetected. + maybe more... And following misfeatures: + SVGALib does not restore screen on exit. + pixclock for text modes is limited by hardware to 83 MHz on G200 66 MHz on Millennium I 60 MHz on Millennium II Because I have no access to other devices, I do not know specific frequencies for them. So driver does not check this and allows you to set frequency higher that this. It causes sparks, black holes and other pretty effects on screen. Device was not destroyed during tests. :-) + my Millennium G200 oscillator has frequency range from 35 MHz to 380 MHz (and it works with 8bpp on about 320 MHz dotclocks (and changed mclk)). But Matrox says on product sheet that VCO limit is 50-250 MHz, so I believe them (maybe that chip overheats, but it has a very big cooler (G100 has none), so it should work). + special mixed video/graphics videomodes of Mystique and Gx00 - 2G8V16 and G16V16 are not supported + color keying is not supported + feature connector of Mystique and Gx00 is set to VGA mode (it is disabled by BIOS) + DCC (monitor detection) protocol is not implemented + some check for input values are not so strict how it should be (you can specify vslen=4000 and so on). + maybe more... And following features: + 4bpp is available only on Millennium I and Millennium II. It is hardware limitation. + current fbset is not able to set 15bpp videomode: you must specify depth==16 and green.length==5. fbset does not allow you to set green.length. + text mode uses 6 bit VGA palette instead of 8 bit (one of 262144 colors instead of one of 16M colors). It is due to hardware limitation of Millennium I/II and SVGALib compatibility. Benchmarks ========== It is time to redraw whole screen 1000 times in 1024x768, 60Hz. It is time for draw 6144000 characters on screen through /dev/vcsa (for 32bpp it is about 3GB of data (exactly 3000 MB); for 8x16 font in 16 seconds, i.e. 187 MBps). Times were obtained from one older version of driver, now they are about 3% faster, it is kernel-space only time on P-II/350 MHz, Millennium I in 33 MHz PCI slot, G200 in AGP 2x slot. I did not test vgacon. NOACCEL 8x16 12x22 Millennium I G200 Millennium I G200 8bpp 16.42 9.54 12.33 9.13 16bpp 21.00 15.70 19.11 15.02 24bpp 36.66 36.66 35.00 35.00 32bpp 35.00 30.00 33.85 28.66 ACCEL, nofastfont 8x16 12x22 6x11 Millennium I G200 Millennium I G200 Millennium I G200 8bpp 7.79 7.24 13.55 7.78 30.00 21.01 16bpp 9.13 7.78 16.16 7.78 30.00 21.01 24bpp 14.17 10.72 18.69 10.24 34.99 21.01 32bpp 16.15 16.16 18.73 13.09 34.99 21.01 ACCEL, fastfont 8x16 12x22 6x11 Millennium I G200 Millennium I G200 Millennium I G200 8bpp 8.41 6.01 6.54 4.37 16.00 10.51 16bpp 9.54 9.12 8.76 6.17 17.52 14.01 24bpp 15.00 12.36 11.67 10.00 22.01 18.32 32bpp 16.18 18.29* 12.71 12.74 24.44 21.00 TEXT 8x16 Millennium I G200 TEXT 3.29 1.50 * Yes, it is slower than Millennium I. -- Petr Vandrovec