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Based on kernel version 3.16. Page generated on 2014-08-06 21:39 EST.

1	Intel 830M/845G/852GM/855GM/865G/915G/945G Framebuffer driver
2	================================================================
3	
4	A. Introduction
5		This is a framebuffer driver for various Intel 8xx/9xx compatible
6	graphics 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		Intel 945GME
18		Intel 965G
19		Intel 965GM
20	
21	B.  List of available options
22	
23	   a. "video=intelfb"
24		enables the intelfb driver
25	
26		Recommendation: required
27	
28	   b. "mode=<xres>x<yres>[-<bpp>][@<refresh>]"
29		select mode
30	
31		Recommendation: user preference
32		(default = 1024x768-32@70)
33	
34	   c. "vram=<value>"
35		select amount of system RAM in MB to allocate for the video memory
36		if not enough RAM was already allocated by the BIOS.
37	
38		Recommendation: 1 - 4 MB.
39		(default = 4 MB)
40	
41	   d. "voffset=<value>"
42	        select at what offset in MB of the logical memory to allocate the
43		framebuffer memory.  The intent is to avoid the memory blocks
44		used by standard graphics applications (XFree86). Depending on your
45	        usage, adjust the value up or down, (0 for maximum usage, 63/127 MB
46	        for the least amount).  Note, an arbitrary setting may conflict
47	        with XFree86.
48	
49		Recommendation: do not set
50		(default = 48 MB)
51	
52	   e. "accel"
53		enable text acceleration.  This can be enabled/reenabled anytime
54		by using 'fbset -accel true/false'.
55	
56		Recommendation: enable
57		(default = set)
58	
59	   f. "hwcursor"
60		enable cursor acceleration.
61	
62		Recommendation: enable
63		(default = set)
64	
65	   g. "mtrr"
66		enable MTRR.  This allows data transfers to the framebuffer memory
67		to occur in bursts which can significantly increase performance.
68		Not very helpful with the intel chips because of 'shared memory'.
69	
70		Recommendation: set
71		(default = set)
72	
73	   h. "fixed"
74		disable mode switching.
75	
76		Recommendation: do not set
77		(default = not set)
78	
79	   The binary parameters can be unset with a "no" prefix, example "noaccel".
80	   The default parameter (not named) is the mode.
81	
82	C. Kernel booting
83	
84	Separate each option/option-pair by commas (,) and the option from its value
85	with an equals sign (=) as in the following:
86	
87	video=intelfb:option1,option2=value2
88	
89	Sample Usage
90	------------
91	
92	In /etc/lilo.conf, add the line:
93	
94	append="video=intelfb:mode=800x600-32@75,accel,hwcursor,vram=8"
95	
96	This will initialize the framebuffer to 800x600 at 32bpp and 75Hz. The
97	framebuffer will use 8 MB of System RAM. hw acceleration of text and cursor
98	will be enabled.
99	
100	Remarks
101	-------
102	
103	If setting this parameter doesn't work (you stay in a 80x25 text-mode),
104	you might need to set the "vga=<mode>" parameter too - see vesafb.txt
105	in this directory.
106	
107	
108	D.  Module options
109	
110		The module parameters are essentially similar to the kernel
111	parameters. The main difference is that you need to include a Boolean value
112	(1 for TRUE, and 0 for FALSE) for those options which don't need a value.
113	
114	Example, to enable MTRR, include "mtrr=1".
115	
116	Sample Usage
117	------------
118	
119	Using the same setup as described above, load the module like this:
120	
121		modprobe intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
122	
123	Or just add the following to a configuration file in /etc/modprobe.d/
124	
125		options intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
126	
127	and just do a
128	
129		modprobe intelfb
130	
131	
132	E.  Acknowledgment:
133	
134		1.  Geert Uytterhoeven - his excellent howto and the virtual
135	                                 framebuffer driver code made this possible.
136	
137		2.  Jeff Hartmann for his agpgart code.
138	
139		3.  David Dawes for his original kernel 2.4 code.
140	
141		4.  The X developers.  Insights were provided just by reading the
142		    XFree86 source code.
143	
144		5.  Antonino A. Daplas for his inspiring i810fb driver.
145	
146		6.  Andrew Morton for his kernel patches maintenance.
147	
148	###########################
149	Sylvain
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