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1Intel 830M/845G/852GM/855GM/865G/915G/945G Framebuffer driver
2================================================================
3
4A. Introduction
5 This is a framebuffer driver for various Intel 8xx/9xx compatible
6graphics devices. These would include:
7
8 Intel 830M
9 Intel 845G
10 Intel 852GM
11 Intel 855GM
12 Intel 865G
13 Intel 915G
14 Intel 915GM
15 Intel 945G
16 Intel 945GM
17
18B. List of available options
19
20 a. "video=intelfb"
21 enables the intelfb driver
22
23 Recommendation: required
24
25 b. "mode=<xres>x<yres>[-<bpp>][@<refresh>]"
26 select mode
27
28 Recommendation: user preference
29 (default = 1024x768-32@70)
30
31 c. "vram=<value>"
32 select amount of system RAM in MB to allocate for the video memory
33 if not enough RAM was already allocated by the BIOS.
34
35 Recommendation: 1 - 4 MB.
36 (default = 4 MB)
37
38 d. "voffset=<value>"
39 select at what offset in MB of the logical memory to allocate the
40 framebuffer memory. The intent is to avoid the memory blocks
41 used by standard graphics applications (XFree86). Depending on your
42 usage, adjust the value up or down, (0 for maximum usage, 63/127 MB
43 for the least amount). Note, an arbitrary setting may conflict
44 with XFree86.
45
46 Recommendation: do not set
47 (default = 48 MB)
48
49 e. "accel"
50 enable text acceleration. This can be enabled/reenabled anytime
51 by using 'fbset -accel true/false'.
52
53 Recommendation: enable
54 (default = set)
55
56 f. "hwcursor"
57 enable cursor acceleration.
58
59 Recommendation: enable
60 (default = set)
61
62 g. "mtrr"
63 enable MTRR. This allows data transfers to the framebuffer memory
64 to occur in bursts which can significantly increase performance.
65 Not very helpful with the intel chips because of 'shared memory'.
66
67 Recommendation: set
68 (default = set)
69
70 h. "fixed"
71 disable mode switching.
72
73 Recommendation: do not set
74 (default = not set)
75
76 The binary parameters can be unset with a "no" prefix, example "noaccel".
77 The default parameter (not named) is the mode.
78
79C. Kernel booting
80
81Separate each option/option-pair by commas (,) and the option from its value
82with an equals sign (=) as in the following:
83
84video=intelfb:option1,option2=value2
85
86Sample Usage
87------------
88
89In /etc/lilo.conf, add the line:
90
91append="video=intelfb:mode=800x600-32@75,accel,hwcursor,vram=8"
92
93This will initialize the framebuffer to 800x600 at 32bpp and 75Hz. The
94framebuffer will use 8 MB of System RAM. hw acceleration of text and cursor
95will be enabled.
96
97Remarks
98-------
99
100If setting this parameter doesn't work (you stay in a 80x25 text-mode),
101you might need to set the "vga=<mode>" parameter too - see vesafb.txt
102in this directory.
103
104
105D. Module options
106
107 The module parameters are essentially similar to the kernel
108parameters. The main difference is that you need to include a Boolean value
109(1 for TRUE, and 0 for FALSE) for those options which don't need a value.
110
111Example, to enable MTRR, include "mtrr=1".
112
113Sample Usage
114------------
115
116Using the same setup as described above, load the module like this:
117
118 modprobe intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
119
120Or just add the following to /etc/modprobe.conf
121
122 options intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
123
124and just do a
125
126 modprobe intelfb
127
128
129E. Acknowledgment:
130
131 1. Geert Uytterhoeven - his excellent howto and the virtual
132 framebuffer driver code made this possible.
133
134 2. Jeff Hartmann for his agpgart code.
135
136 3. David Dawes for his original kernel 2.4 code.
137
138 4. The X developers. Insights were provided just by reading the
139 XFree86 source code.
140
141 5. Antonino A. Daplas for his inspiring i810fb driver.
142
143 6. Andrew Morton for his kernel patches maintenance.
144
145###########################
146Sylvain