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	Intel 945GME
 18	Intel 965G
 19	Intel 965GM
 20
 21B.  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
 82C. Kernel booting
 83
 84Separate each option/option-pair by commas (,) and the option from its value
 85with an equals sign (=) as in the following:
 86
 87video=intelfb:option1,option2=value2
 88
 89Sample Usage
 90------------
 91
 92In /etc/lilo.conf, add the line:
 93
 94append="video=intelfb:mode=800x600-32@75,accel,hwcursor,vram=8"
 95
 96This will initialize the framebuffer to 800x600 at 32bpp and 75Hz. The
 97framebuffer will use 8 MB of System RAM. hw acceleration of text and cursor
 98will be enabled.
 99
100Remarks
101-------
102
103If setting this parameter doesn't work (you stay in a 80x25 text-mode),
104you might need to set the "vga=<mode>" parameter too - see vesafb.txt
105in this directory.
106
107
108D.  Module options
109
110	The module parameters are essentially similar to the kernel
111parameters. 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
114Example, to enable MTRR, include "mtrr=1".
115
116Sample Usage
117------------
118
119Using 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
123Or 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
127and just do a
128
129	modprobe intelfb
130
131
132E.  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###########################
149Sylvain