1==============
2What is sisfb?
3==============
4
5sisfb is a framebuffer device driver for SiS (Silicon Integrated Systems)
6graphics chips. Supported are:
7
8- SiS 300 series: SiS 300/305, 540, 630(S), 730(S)
9- SiS 315 series: SiS 315/H/PRO, 55x, (M)65x, 740, (M)661(F/M)X, (M)741(GX)
10- SiS 330 series: SiS 330 ("Xabre"), (M)760
11
12
13Why do I need a framebuffer driver?
14===================================
15
16sisfb is eg. useful if you want a high-resolution text console. Besides that,
17sisfb is required to run DirectFB (which comes with an additional, dedicated
18driver for the 315 series).
19
20On the 300 series, sisfb on kernels older than 2.6.3 furthermore plays an
21important role in connection with DRM/DRI: Sisfb manages the memory heap
22used by DRM/DRI for 3D texture and other data. This memory management is
23required for using DRI/DRM.
24
25Kernels >= around 2.6.3 do not need sisfb any longer for DRI/DRM memory
26management. The SiS DRM driver has been updated and features a memory manager
27of its own (which will be used if sisfb is not compiled). So unless you want
28a graphical console, you don't need sisfb on kernels >=2.6.3.
29
30Sidenote: Since this seems to be a commonly made mistake: sisfb and vesafb
31cannot be active at the same time! Do only select one of them in your kernel
32configuration.
33
34
35How are parameters passed to sisfb?
36===================================
37
38Well, it depends: If compiled statically into the kernel, use lilo's append
39statement to add the parameters to the kernel command line. Please see lilo's
40(or GRUB's) documentation for more information. If sisfb is a kernel module,
41parameters are given with the modprobe (or insmod) command.
42
43Example for sisfb as part of the static kernel: Add the following line to your
44lilo.conf::
45
46     append="video=sisfb:mode:1024x768x16,mem:12288,rate:75"
47
48Example for sisfb as a module: Start sisfb by typing::
49
50     modprobe sisfb mode=1024x768x16 rate=75 mem=12288
51
52A common mistake is that folks use a wrong parameter format when using the
53driver compiled into the kernel. Please note: If compiled into the kernel,
54the parameter format is video=sisfb:mode:none or video=sisfb:mode:1024x768x16
55(or whatever mode you want to use, alternatively using any other format
56described above or the vesa keyword instead of mode). If compiled as a module,
57the parameter format reads mode=none or mode=1024x768x16 (or whatever mode you
58want to use). Using a "=" for a ":" (and vice versa) is a huge difference!
59Additionally: If you give more than one argument to the in-kernel sisfb, the
60arguments are separated with ",". For example::
61
62   video=sisfb:mode:1024x768x16,rate:75,mem:12288
63
64
65How do I use it?
66================
67
68Preface statement: This file only covers very little of the driver's
69capabilities and features. Please refer to the author's and maintainer's
70website at http://www.winischhofer.net/linuxsisvga.shtml for more
71information. Additionally, "modinfo sisfb" gives an overview over all
72supported options including some explanation.
73
74The desired display mode can be specified using the keyword "mode" with
75a parameter in one of the following formats:
76
77  - XxYxDepth or
78  - XxY-Depth or
79  - XxY-Depth@Rate or
80  - XxY
81  - or simply use the VESA mode number in hexadecimal or decimal.
82
83For example: 1024x768x16, 1024x768-16@75, 1280x1024-16. If no depth is
84specified, it defaults to 8. If no rate is given, it defaults to 60Hz. Depth 32
85means 24bit color depth (but 32 bit framebuffer depth, which is not relevant
86to the user).
87
88Additionally, sisfb understands the keyword "vesa" followed by a VESA mode
89number in decimal or hexadecimal. For example: vesa=791 or vesa=0x117. Please
90use either "mode" or "vesa" but not both.
91
92Linux 2.4 only: If no mode is given, sisfb defaults to "no mode" (mode=none) if
93compiled as a module; if sisfb is statically compiled into the kernel, it
94defaults to 800x600x8 unless CRT2 type is LCD, in which case the LCD's native
95resolution is used. If you want to switch to a different mode, use the fbset
96shell command.
97
98Linux 2.6 only: If no mode is given, sisfb defaults to 800x600x8 unless CRT2
99type is LCD, in which case it defaults to the LCD's native resolution. If
100you want to switch to another mode, use the stty shell command.
101
102You should compile in both vgacon (to boot if you remove you SiS card from
103your system) and sisfb (for graphics mode). Under Linux 2.6, also "Framebuffer
104console support" (fbcon) is needed for a graphical console.
105
106You should *not* compile-in vesafb. And please do not use the "vga=" keyword
107in lilo's or grub's configuration file; mode selection is done using the
108"mode" or "vesa" keywords as a parameter. See above and below.
109
110
111X11
112===
113
114If using XFree86 or X.org, it is recommended that you don't use the "fbdev"
115driver but the dedicated "sis" X driver. The "sis" X driver and sisfb are
116developed by the same person (Thomas Winischhofer) and cooperate well with
117each other.
118
119
120SVGALib
121=======
122
123SVGALib, if directly accessing the hardware, never restores the screen
124correctly, especially on laptops or if the output devices are LCD or TV.
125Therefore, use the chipset "FBDEV" in SVGALib configuration. This will make
126SVGALib use the framebuffer device for mode switches and restoration.
127
128
129Configuration
130=============
131
132(Some) accepted options:
133
134=========  ==================================================================
135off        Disable sisfb. This option is only understood if sisfb is
136	   in-kernel, not a module.
137mem:X      size of memory for the console, rest will be used for DRI/DRM. X
138	   is in kilobytes. On 300 series, the default is 4096, 8192 or
139	   16384 (each in kilobyte) depending on how much video ram the card
140	   has. On 315/330 series, the default is the maximum available ram
141	   (since DRI/DRM is not supported for these chipsets).
142noaccel    do not use 2D acceleration engine. (Default: use acceleration)
143noypan     disable y-panning and scroll by redrawing the entire screen.
144	   This is much slower than y-panning. (Default: use y-panning)
145vesa:X     selects startup videomode. X is number from 0 to 0x1FF and
146	   represents the VESA mode number (can be given in decimal or
147	   hexadecimal form, the latter prefixed with "0x").
148mode:X     selects startup videomode. Please see above for the format of
149	   "X".
150=========  ==================================================================
151
152Boolean options such as "noaccel" or "noypan" are to be given without a
153parameter if sisfb is in-kernel (for example "video=sisfb:noypan). If
154sisfb is a module, these are to be set to 1 (for example "modprobe sisfb
155noypan=1").
156
157
158Thomas Winischhofer <thomas@winischhofer.net>
159
160May 27, 2004
161