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diff --git a/Documentation/fb/sisfb.txt b/Documentation/fb/sisfb.txt new file mode 100644 index 000000000000..3b50c517a08d --- /dev/null +++ b/Documentation/fb/sisfb.txt @@ -0,0 +1,158 @@ + +What is sisfb? +============== + +sisfb is a framebuffer device driver for SiS (Silicon Integrated Systems) +graphics chips. Supported are: + +- SiS 300 series: SiS 300/305, 540, 630(S), 730(S) +- SiS 315 series: SiS 315/H/PRO, 55x, (M)65x, 740, (M)661(F/M)X, (M)741(GX) +- SiS 330 series: SiS 330 ("Xabre"), (M)760 + + +Why do I need a framebuffer driver? +=================================== + +sisfb is eg. useful if you want a high-resolution text console. Besides that, +sisfb is required to run DirectFB (which comes with an additional, dedicated +driver for the 315 series). + +On the 300 series, sisfb on kernels older than 2.6.3 furthermore plays an +important role in connection with DRM/DRI: Sisfb manages the memory heap +used by DRM/DRI for 3D texture and other data. This memory management is +required for using DRI/DRM. + +Kernels >= around 2.6.3 do not need sisfb any longer for DRI/DRM memory +management. The SiS DRM driver has been updated and features a memory manager +of its own (which will be used if sisfb is not compiled). So unless you want +a graphical console, you don't need sisfb on kernels >=2.6.3. + +Sidenote: Since this seems to be a commonly made mistake: sisfb and vesafb +cannot be active at the same time! Do only select one of them in your kernel +configuration. + + +How are parameters passed to sisfb? +=================================== + +Well, it depends: If compiled statically into the kernel, use lilo's append +statement to add the parameters to the kernel command line. Please see lilo's +(or GRUB's) documentation for more information. If sisfb is a kernel module, +parameters are given with the modprobe (or insmod) command. + +Example for sisfb as part of the static kernel: Add the following line to your +lilo.conf: + + append="video=sisfb:mode:1024x768x16,mem:12288,rate:75" + +Example for sisfb as a module: Start sisfb by typing + + modprobe sisfb mode=1024x768x16 rate=75 mem=12288 + +A common mistake is that folks use a wrong parameter format when using the +driver compiled into the kernel. Please note: If compiled into the kernel, +the parameter format is video=sisfb:mode:none or video=sisfb:mode:1024x768x16 +(or whatever mode you want to use, alternatively using any other format +described above or the vesa keyword instead of mode). If compiled as a module, +the parameter format reads mode=none or mode=1024x768x16 (or whatever mode you +want to use). Using a "=" for a ":" (and vice versa) is a huge difference! +Additionally: If you give more than one argument to the in-kernel sisfb, the +arguments are separated with ",". For example: + + video=sisfb:mode:1024x768x16,rate:75,mem:12288 + + +How do I use it? +================ + +Preface statement: This file only covers very little of the driver's +capabilities and features. Please refer to the author's and maintainer's +website at http://www.winischhofer.net/linuxsisvga.shtml for more +information. Additionally, "modinfo sisfb" gives an overview over all +supported options including some explanation. + +The desired display mode can be specified using the keyword "mode" with +a parameter in one of the follwing formats: + - XxYxDepth or + - XxY-Depth or + - XxY-Depth@Rate or + - XxY + - or simply use the VESA mode number in hexadecimal or decimal. + +For example: 1024x768x16, 1024x768-16@75, 1280x1024-16. If no depth is +specified, it defaults to 8. If no rate is given, it defaults to 60Hz. Depth 32 +means 24bit color depth (but 32 bit framebuffer depth, which is not relevant +to the user). + +Additionally, sisfb understands the keyword "vesa" followed by a VESA mode +number in decimal or hexadecimal. For example: vesa=791 or vesa=0x117. Please +use either "mode" or "vesa" but not both. + +Linux 2.4 only: If no mode is given, sisfb defaults to "no mode" (mode=none) if +compiled as a module; if sisfb is statically compiled into the kernel, it +defaults to 800x600x8 unless CRT2 type is LCD, in which case the LCD's native +resolution is used. If you want to switch to a different mode, use the fbset +shell command. + +Linux 2.6 only: If no mode is given, sisfb defaults to 800x600x8 unless CRT2 +type is LCD, in which case it defaults to the LCD's native resolution. If +you want to switch to another mode, use the stty shell command. + +You should compile in both vgacon (to boot if you remove you SiS card from +your system) and sisfb (for graphics mode). Under Linux 2.6, also "Framebuffer +console support" (fbcon) is needed for a graphical console. + +You should *not* compile-in vesafb. And please do not use the "vga=" keyword +in lilo's or grub's configuration file; mode selection is done using the +"mode" or "vesa" keywords as a parameter. See above and below. + + +X11 +=== + +If using XFree86 or X.org, it is recommended that you don't use the "fbdev" +driver but the dedicated "sis" X driver. The "sis" X driver and sisfb are +developed by the same person (Thomas Winischhofer) and cooperate well with +each other. + + +SVGALib +======= + +SVGALib, if directly accessing the hardware, never restores the screen +correctly, especially on laptops or if the output devices are LCD or TV. +Therefore, use the chipset "FBDEV" in SVGALib configuration. This will make +SVGALib use the framebuffer device for mode switches and restoration. + + +Configuration +============= + +(Some) accepted options: + +off - Disable sisfb. This option is only understood if sisfb is + in-kernel, not a module. +mem:X - size of memory for the console, rest will be used for DRI/DRM. X + is in kilobytes. On 300 series, the default is 4096, 8192 or + 16384 (each in kilobyte) depending on how much video ram the card + has. On 315/330 series, the default is the maximum available ram + (since DRI/DRM is not supported for these chipsets). +noaccel - do not use 2D acceleration engine. (Default: use acceleration) +noypan - disable y-panning and scroll by redrawing the entire screen. + This is much slower than y-panning. (Default: use y-panning) +vesa:X - selects startup videomode. X is number from 0 to 0x1FF and + represents the VESA mode number (can be given in decimal or + hexadecimal form, the latter prefixed with "0x"). +mode:X - selects startup videomode. Please see above for the format of + "X". + +Boolean options such as "noaccel" or "noypan" are to be given without a +parameter if sisfb is in-kernel (for example "video=sisfb:noypan). If +sisfb is a module, these are to be set to 1 (for example "modprobe sisfb +noypan=1"). + +-- +Thomas Winischhofer <thomas@winischhofer.net> +May 27, 2004 + + |