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Diffstat (limited to 'Documentation/fb/vesafb.txt')
| -rw-r--r-- | Documentation/fb/vesafb.txt | 85 |
1 files changed, 57 insertions, 28 deletions
diff --git a/Documentation/fb/vesafb.txt b/Documentation/fb/vesafb.txt index ed58f7241..e6f52393d 100644 --- a/Documentation/fb/vesafb.txt +++ b/Documentation/fb/vesafb.txt @@ -30,37 +30,66 @@ How to use it? ============== Switching modes is done using the vga=... boot parameter. Read -Documentation/svga.txt for details. With vesafb both text and -graphics modes work. Text modes are handled by vgafb, graphic modes -by the new vesafb.c. +Documentation/svga.txt for details. -The graphic modes are not in the list which you get if you boot with -vga=ask and hit return. Here are some mode numbers: - - | 640x480 800x600 1024x768 -----+--------------------------- -256 | 0x101 0x103 0x105 -32k | 0x110 0x113 0x116 -64k | 0x111 0x114 0x117 -16M | 0x112 0x115 0x118 - -Note 1: this are the VESA mode numbers. The video mode select code - expects 0x200 + VESA mode number. -Note 2: lilo can't handle hex, for booting with "vga=??" you have to - transform the numbers to decimal. +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. Here are some mode numbers: -Speed it up! -============ - -Check /usr/src/linux/Documentation/mtrr.txt, enabling write-combining -for the framebuffer memory gives a performance boost. - -There are two ways to do console scrolling: redraw the screen -completely, or by copying around the video memory. You can select one -of them using the kernel command line: video=vesa:redraw or -video=vesa:memmove. redraw is the default, becauce this one works -faster on my box. + | 640x480 800x600 1024x768 1280x1024 +----+------------------------------------- +256 | 0x101 0x103 0x105 0x107 +32k | 0x110 0x113 0x116 0x119 +64k | 0x111 0x114 0x117 0x11A +16M | 0x112 0x115 0x118 0x11B + +This are the VESA mode numbers. The video mode select code expects +0x200 + VESA mode number. Therefore you have to enter "305" at the +"vga=ask" prompt to boot into 1024x768x8. + +If this does'nt work, this might be becauce your BIOS does not support +linear framebuffers or becauce it does'nt support this mode at all. +Even if your board does, it might be the BIOS does not. VESA BIOS +Extentions v2.0 are required, 1.2 is NOT sufficient. You'll get a +"bad mode number" message if something goes wrong. + +Note: LILO can't handle hex, for booting directly with "vga=mode-number" + you have to transform the numbers to decimal. + + +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 can't do anything about this). + + +Configuration +============= + +You can pass kernel command line options to vesafb with +"video=vesa:option1". Multiple options should be separated +by comma. Accepted options: + +invers - no comment... +redraw - scroll by redrawing the affected part of the screen +ypan - enable display panning using the VESA protected mode + interface. This enables the Shift-PgUp scrollback + thing and greatly speeds up fullscreen scrolling. + It is slower than "redraw" when scrolling only a halve + screen. This is the default. +ywrap - If your gfx board supports wrap-around, use this one + instead of ypan. +nopal - Don't use the protected mode interface for palette + changes. vesafb will try the standard vga registers + instead. Have fun! |