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1Intel 830M/845G/852GM/855GM/865G/915G Framebuffer driver
2================================================================
3
4A. Introduction
5 This is a framebuffer driver for various Intel 810/815 compatible
6graphics devices. These would include:
7
8 Intel 830M
9 Intel 810E845G
10 Intel 852GM
11 Intel 855GM
12 Intel 865G
13 Intel 915G
14
15B. List of available options
16
17 a. "video=intelfb"
18 enables the intelfb driver
19
20 Recommendation: required
21
22 b. "mode=<xres>x<yres>[-<bpp>][@<refresh>]"
23 select mode
24
25 Recommendation: user preference
26 (default = 1024x768-32@70)
27
28 c. "vram=<value>"
29 select amount of system RAM in MB to allocate for the video memory
30 if not enough RAM was already allocated by the BIOS.
31
32 Recommendation: 1 - 4 MB.
33 (default = 4 MB)
34
35 d. "voffset=<value>"
36 select at what offset in MB of the logical memory to allocate the
37 framebuffer memory. The intent is to avoid the memory blocks
38 used by standard graphics applications (XFree86). Depending on your
39 usage, adjust the value up or down, (0 for maximum usage, 63/127 MB
40 for the least amount). Note, an arbitrary setting may conflict
41 with XFree86.
42
43 Recommendation: do not set
44 (default = 48 MB)
45
46 e. "accel"
47 enable text acceleration. This can be enabled/reenabled anytime
48 by using 'fbset -accel true/false'.
49
50 Recommendation: enable
51 (default = set)
52
53 f. "hwcursor"
54 enable cursor acceleration.
55
56 Recommendation: enable
57 (default = set)
58
59 g. "mtrr"
60 enable MTRR. This allows data transfers to the framebuffer memory
61 to occur in bursts which can significantly increase performance.
62 Not very helpful with the intel chips because of 'shared memory'.
63
64 Recommendation: set
65 (default = set)
66
67 h. "fixed"
68 disable mode switching.
69
70 Recommendation: do not set
71 (default = not set)
72
73 The binary parameters can be unset with a "no" prefix, example "noaccel".
74 The default parameter (not named) is the mode.
75
76C. Kernel booting
77
78Separate each option/option-pair by commas (,) and the option from its value
79with an equals sign (=) as in the following:
80
81video=i810fb:option1,option2=value2
82
83Sample Usage
84------------
85
86In /etc/lilo.conf, add the line:
87
88append="video=intelfb:800x600-32@75,accel,hwcursor,vram=8"
89
90This will initialize the framebuffer to 800x600 at 32bpp and 75Hz. The
91framebuffer will use 8 MB of System RAM. hw acceleration of text and cursor
92will be enabled.
93
94D. Module options
95
96 The module parameters are essentially similar to the kernel
97parameters. The main difference is that you need to include a Boolean value
98(1 for TRUE, and 0 for FALSE) for those options which don't need a value.
99
100Example, to enable MTRR, include "mtrr=1".
101
102Sample Usage
103------------
104
105Using the same setup as described above, load the module like this:
106
107 modprobe intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
108
109Or just add the following to /etc/modprobe.conf
110
111 options intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
112
113and just do a
114
115 modprobe intelfb
116
117
118E. Acknowledgment:
119
120 1. Geert Uytterhoeven - his excellent howto and the virtual
121 framebuffer driver code made this possible.
122
123 2. Jeff Hartmann for his agpgart code.
124
125 3. David Dawes for his original kernel 2.4 code.
126
127 4. The X developers. Insights were provided just by reading the
128 XFree86 source code.
129
130 5. Antonino A. Daplas for his inspiring i810fb driver.
131
132 6. Andrew Morton for his kernel patches maintenance.
133
134###########################
135Sylvain