Documentation/fb/sisfb.txt - linux-mtk - Git at Google



            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 following 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

	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 following 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