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diff --git a/Documentation/fb/vesafb.txt b/Documentation/fb/vesafb.txt deleted file mode 100644 index 413bb73235be..000000000000 --- a/Documentation/fb/vesafb.txt +++ /dev/null @@ -1,181 +0,0 @@ - -What is vesafb? -=============== - -This is a generic driver for a graphic framebuffer on intel boxes. - -The idea is simple: Turn on graphics mode at boot time with the help -of the BIOS, and use this as framebuffer device /dev/fb0, like the m68k -(and other) ports do. - -This means we decide at boot time whenever we want to run in text or -graphics mode. Switching mode later on (in protected mode) is -impossible; BIOS calls work in real mode only. VESA BIOS Extensions -Version 2.0 are required, because we need a linear frame buffer. - -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 (=> non-accelerated X11 - support for every VBE 2.0 compliant graphics board). - * Most important: boot logo :-) - -Disadvantages: - - * graphic mode is slower than text mode... - - -How to use it? -============== - -Switching modes is done using the vga=... boot parameter. Read -Documentation/svga.txt for details. - -You should compile in both vgacon (for text mode) and vesafb (for -graphics mode). Which of them takes over the console depends on -whenever the specified mode is text or graphics. - -The graphic modes are NOT in the list which you get if you boot with -vga=ask and hit return. The mode you wish to use is derived from the -VESA mode number. Here are those VESA mode numbers: - - | 640x480 800x600 1024x768 1280x1024 -----+------------------------------------- -256 | 0x101 0x103 0x105 0x107 -32k | 0x110 0x113 0x116 0x119 -64k | 0x111 0x114 0x117 0x11A -16M | 0x112 0x115 0x118 0x11B - -The video mode number of the Linux kernel is the VESA mode number plus -0x200. - - Linux_kernel_mode_number = VESA_mode_number + 0x200 - -So the table for the Kernel mode numbers are: - - | 640x480 800x600 1024x768 1280x1024 -----+------------------------------------- -256 | 0x301 0x303 0x305 0x307 -32k | 0x310 0x313 0x316 0x319 -64k | 0x311 0x314 0x317 0x31A -16M | 0x312 0x315 0x318 0x31B - -To enable one of those modes you have to specify "vga=ask" in the -lilo.conf file and rerun LILO. Then you can type in the desired -mode at the "vga=ask" prompt. For example if you like to use -1024x768x256 colors you have to say "305" at this prompt. - -If this does not work, this might be because your BIOS does not support -linear framebuffers or because it does not support this mode at all. -Even if your board does, it might be the BIOS which does not. VESA BIOS -Extensions v2.0 are required, 1.2 is NOT sufficient. You will get a -"bad mode number" message if something goes wrong. - -1. Note: LILO cannot handle hex, for booting directly with - "vga=mode-number" you have to transform the numbers to decimal. -2. Note: Some newer versions of LILO appear to work with those hex values, - if you set the 0x in front of the numbers. - -X11 -=== - -XF68_FBDev should work just fine, but it is non-accelerated. Running -another (accelerated) X-Server like XF86_SVGA might or might not work. -It depends on X-Server and graphics board. - -The X-Server must restore the video mode correctly, else you end up -with a broken console (and vesafb cannot do anything about this). - - -Refresh rates -============= - -There is no way to change the vesafb video mode and/or timings after -booting linux. If you are not happy with the 60 Hz refresh rate, you -have these options: - - * configure and load the DOS-Tools for the graphics board (if - available) and boot linux with loadlin. - * use a native driver (matroxfb/atyfb) instead if vesafb. If none - is available, write a new one! - * VBE 3.0 might work too. I have neither a gfx board with VBE 3.0 - support nor the specs, so I have not checked this yet. - - -Configuration -============= - -The VESA BIOS provides protected mode interface for changing -some parameters. vesafb can use it for palette changes and -to pan the display. It is turned off by default because it -seems not to work with some BIOS versions, but there are options -to turn it on. - -You can pass options to vesafb using "video=vesafb:option" on -the kernel command line. Multiple options should be separated -by comma, like this: "video=vesafb:ypan,inverse" - -Accepted options: - -inverse use inverse color map - -ypan enable display panning using the VESA protected mode - interface. The visible screen is just a window of the - video memory, console scrolling is done by changing the - start of the window. - pro: * scrolling (fullscreen) is fast, because there is - no need to copy around data. - * You'll get scrollback (the Shift-PgUp thing), - the video memory can be used as scrollback buffer - kontra: * scrolling only parts of the screen causes some - ugly flicker effects (boot logo flickers for - example). - -ywrap Same as ypan, but assumes your gfx board can wrap-around - the video memory (i.e. starts reading from top if it - reaches the end of video memory). Faster than ypan. - -redraw scroll by redrawing the affected part of the screen, this - is the safe (and slow) default. - - -vgapal Use the standard vga registers for palette changes. - This is the default. -pmipal Use the protected mode interface for palette changes. - -mtrr:n setup memory type range registers for the vesafb framebuffer - where n: - 0 - disabled (equivalent to nomtrr) (default) - 1 - uncachable - 2 - write-back - 3 - write-combining - 4 - write-through - - If you see the following in dmesg, choose the type that matches the - old one. In this example, use "mtrr:2". -... -mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining -... - -nomtrr disable mtrr - -vremap:n - remap 'n' MiB of video RAM. If 0 or not specified, remap memory - according to video mode. (2.5.66 patch/idea by Antonino Daplas - reversed to give override possibility (allocate more fb memory - than the kernel would) to 2.4 by tmb@iki.fi) - -vtotal:n - if the video BIOS of your card incorrectly determines the total - amount of video RAM, use this option to override the BIOS (in MiB). - -Have fun! - - Gerd - --- -Gerd Knorr <kraxel@goldbach.in-berlin.de> - -Minor (mostly typo) changes -by Nico Schmoigl <schmoigl@rumms.uni-mannheim.de> |