Eric Lee / linux-smarc-t335x-v3.2

Commit 4ff45f515144d232c83bf55c53f54deecb750296

Authored by Sylvain Meyer 2005-06-22 08:17:03 +0800

Committed by Linus Torvalds 2005-06-22 10:07:40 +0800

Exists in master and in 4 other branches

[PATCH] intelfb documentation

Add a small documentation of the driver parameters.

Signed-off-by: Sylvain Meyer <sylvain.meyer@worldonline.fr>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Showing 1 changed file with 135 additions and 0 deletions Side-by-side Diff

Documentation/fb/intelfb.txt

Documentation/fb/intelfb.txt

Diff comments View file @ 4ff45f5

	1	+Intel 830M/845G/852GM/855GM/865G/915G Framebuffer driver
	2	+================================================================
	3	+
	4	+A. Introduction
	5	+ This is a framebuffer driver for various Intel 810/815 compatible
	6	+graphics devices. These would include:
	7	+
	8	+ Intel 830M
	9	+ Intel 810E845G
	10	+ Intel 852GM
	11	+ Intel 855GM
	12	+ Intel 865G
	13	+ Intel 915G
	14	+
	15	+B. 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	+
	76	+C. Kernel booting
	77	+
	78	+Separate each option/option-pair by commas (,) and the option from its value
	79	+with an equals sign (=) as in the following:
	80	+
	81	+video=i810fb:option1,option2=value2
	82	+
	83	+Sample Usage
	84	+------------
	85	+
	86	+In /etc/lilo.conf, add the line:
	87	+
	88	+append="video=intelfb:800x600-32@75,accel,hwcursor,vram=8"
	89	+
	90	+This will initialize the framebuffer to 800x600 at 32bpp and 75Hz. The
	91	+framebuffer will use 8 MB of System RAM. hw acceleration of text and cursor
	92	+will be enabled.
	93	+
	94	+D. Module options
	95	+
	96	+ The module parameters are essentially similar to the kernel
	97	+parameters. 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	+
	100	+Example, to enable MTRR, include "mtrr=1".
	101	+
	102	+Sample Usage
	103	+------------
	104	+
	105	+Using 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	+
	109	+Or just add the following to /etc/modprobe.conf
	110	+
	111	+ options intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1
	112	+
	113	+and just do a
	114	+
	115	+ modprobe intelfb
	116	+
	117	+
	118	+E. 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	+###########################
	135	+Sylvain