[linux-block.git] / Documentation / fb / intelfb.txt

Intel 830M/845G/852GM/855GM/865G/915G/945G Framebuffer driver
================================================================

A. Introduction
	This is a framebuffer driver for various Intel 8xx/9xx compatible
graphics devices.  These would include:

	Intel 830M
	Intel 845G
	Intel 852GM
	Intel 855GM
	Intel 865G
	Intel 915G
	Intel 915GM
	Intel 945G
	Intel 945GM

B.  List of available options

   a. "video=intelfb"
	enables the intelfb driver

	Recommendation: required

   b. "mode=<xres>x<yres>[-<bpp>][@<refresh>]"
	select mode

	Recommendation: user preference
	(default = 1024x768-32@70)

   c. "vram=<value>"
	select amount of system RAM in MB to allocate for the video memory
	if not enough RAM was already allocated by the BIOS.

	Recommendation: 1 - 4 MB.
	(default = 4 MB)

   d. "voffset=<value>"
        select at what offset in MB of the logical memory to allocate the
	framebuffer memory.  The intent is to avoid the memory blocks
	used by standard graphics applications (XFree86). Depending on your
        usage, adjust the value up or down, (0 for maximum usage, 63/127 MB
        for the least amount).  Note, an arbitrary setting may conflict
        with XFree86.

	Recommendation: do not set
	(default = 48 MB)

   e. "accel"
	enable text acceleration.  This can be enabled/reenabled anytime
	by using 'fbset -accel true/false'.

	Recommendation: enable
	(default = set)

   f. "hwcursor"
	enable cursor acceleration.

	Recommendation: enable
	(default = set)

   g. "mtrr"
	enable MTRR.  This allows data transfers to the framebuffer memory
	to occur in bursts which can significantly increase performance.
	Not very helpful with the intel chips because of 'shared memory'.

	Recommendation: set
	(default = set)

   h. "fixed"
	disable mode switching.

	Recommendation: do not set
	(default = not set)

   The binary parameters can be unset with a "no" prefix, example "noaccel".
   The default parameter (not named) is the mode.

C. Kernel booting

Separate each option/option-pair by commas (,) and the option from its value
with an equals sign (=) as in the following:

video=intelfb:option1,option2=value2

Sample Usage
------------

In /etc/lilo.conf, add the line:

append="video=intelfb:800x600-32@75,accel,hwcursor,vram=8"

This will initialize the framebuffer to 800x600 at 32bpp and 75Hz. The
framebuffer will use 8 MB of System RAM. hw acceleration of text and cursor
will be enabled.

D.  Module options

	The module parameters are essentially similar to the kernel
parameters. The main difference is that you need to include a Boolean value
(1 for TRUE, and 0 for FALSE) for those options which don't need a value.

Example, to enable MTRR, include "mtrr=1".

Sample Usage
------------

Using the same setup as described above, load the module like this:

	modprobe intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1

Or just add the following to /etc/modprobe.conf

	options intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1

and just do a

	modprobe intelfb


E.  Acknowledgment:

	1.  Geert Uytterhoeven - his excellent howto and the virtual
                                 framebuffer driver code made this possible.

	2.  Jeff Hartmann for his agpgart code.

	3.  David Dawes for his original kernel 2.4 code.

	4.  The X developers.  Insights were provided just by reading the
	    XFree86 source code.

	5.  Antonino A. Daplas for his inspiring i810fb driver.

	6.  Andrew Morton for his kernel patches maintenance.

###########################
Sylvain
Commit	Line	Data
d463d34e	1	Intel 830M/845G/852GM/855GM/865G/915G/945G Framebuffer driver
4ff45f51 SM	2	================================================================
	3
	4	A. Introduction
d463d34e	5	This is a framebuffer driver for various Intel 8xx/9xx compatible
4ff45f51 SM	6	graphics devices. These would include:
	7
	8	Intel 830M
d463d34e	9	Intel 845G
4ff45f51 SM	10	Intel 852GM
	11	Intel 855GM
	12	Intel 865G
	13	Intel 915G
d463d34e CM	14	Intel 915GM
	15	Intel 945G
	16	Intel 945GM
4ff45f51 SM	17
	18	B. 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
	79	C. Kernel booting
	80
81	Separate each option/option-pair by commas (,) and the option from its value
82	with an equals sign (=) as in the following:
83
d463d34e	84	video=intelfb:option1,option2=value2
4ff45f51 SM	85
	86	Sample Usage
	87	------------
	88
	89	In /etc/lilo.conf, add the line:
	90
	91	append="video=intelfb:800x600-32@75,accel,hwcursor,vram=8"
	92
	93	This will initialize the framebuffer to 800x600 at 32bpp and 75Hz. The
	94	framebuffer will use 8 MB of System RAM. hw acceleration of text and cursor
	95	will be enabled.
	96
	97	D. Module options
	98
	99	The module parameters are essentially similar to the kernel
	100	parameters. The main difference is that you need to include a Boolean value
	101	(1 for TRUE, and 0 for FALSE) for those options which don't need a value.
	102
	103	Example, to enable MTRR, include "mtrr=1".
	104
	105	Sample Usage
	106	------------
	107
	108	Using the same setup as described above, load the module like this:
	109
	110	modprobe intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
	111
	112	Or just add the following to /etc/modprobe.conf
	113
	114	options intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
	115
	116	and just do a
	117
	118	modprobe intelfb
	119
	120
	121	E. Acknowledgment:
	122
	123	1. Geert Uytterhoeven - his excellent howto and the virtual
	124	framebuffer driver code made this possible.
	125
	126	2. Jeff Hartmann for his agpgart code.
	127
	128	3. David Dawes for his original kernel 2.4 code.
	129
	130	4. The X developers. Insights were provided just by reading the
	131	XFree86 source code.
	132
	133	5. Antonino A. Daplas for his inspiring i810fb driver.
	134
	135	6. Andrew Morton for his kernel patches maintenance.
	136
	137	###########################
	138	Sylvain