intelfb.rst (3861B)
1============================================================= 2Intel 830M/845G/852GM/855GM/865G/915G/945G Framebuffer driver 3============================================================= 4 5A. Introduction 6=============== 7 8This is a framebuffer driver for various Intel 8xx/9xx compatible 9graphics devices. These would include: 10 11 - Intel 830M 12 - Intel 845G 13 - Intel 852GM 14 - Intel 855GM 15 - Intel 865G 16 - Intel 915G 17 - Intel 915GM 18 - Intel 945G 19 - Intel 945GM 20 - Intel 945GME 21 - Intel 965G 22 - Intel 965GM 23 24B. List of available options 25============================= 26 27 a. "video=intelfb" 28 enables the intelfb driver 29 30 Recommendation: required 31 32 b. "mode=<xres>x<yres>[-<bpp>][@<refresh>]" 33 select mode 34 35 Recommendation: user preference 36 (default = 1024x768-32@70) 37 38 c. "vram=<value>" 39 select amount of system RAM in MB to allocate for the video memory 40 if not enough RAM was already allocated by the BIOS. 41 42 Recommendation: 1 - 4 MB. 43 (default = 4 MB) 44 45 d. "voffset=<value>" 46 select at what offset in MB of the logical memory to allocate the 47 framebuffer memory. The intent is to avoid the memory blocks 48 used by standard graphics applications (XFree86). Depending on your 49 usage, adjust the value up or down, (0 for maximum usage, 63/127 MB 50 for the least amount). Note, an arbitrary setting may conflict 51 with XFree86. 52 53 Recommendation: do not set 54 (default = 48 MB) 55 56 e. "accel" 57 enable text acceleration. This can be enabled/reenabled anytime 58 by using 'fbset -accel true/false'. 59 60 Recommendation: enable 61 (default = set) 62 63 f. "hwcursor" 64 enable cursor acceleration. 65 66 Recommendation: enable 67 (default = set) 68 69 g. "mtrr" 70 enable MTRR. This allows data transfers to the framebuffer memory 71 to occur in bursts which can significantly increase performance. 72 Not very helpful with the intel chips because of 'shared memory'. 73 74 Recommendation: set 75 (default = set) 76 77 h. "fixed" 78 disable mode switching. 79 80 Recommendation: do not set 81 (default = not set) 82 83 The binary parameters can be unset with a "no" prefix, example "noaccel". 84 The default parameter (not named) is the mode. 85 86C. Kernel booting 87================= 88 89Separate each option/option-pair by commas (,) and the option from its value 90with an equals sign (=) as in the following:: 91 92 video=intelfb:option1,option2=value2 93 94Sample Usage 95------------ 96 97In /etc/lilo.conf, add the line:: 98 99 append="video=intelfb:mode=800x600-32@75,accel,hwcursor,vram=8" 100 101This will initialize the framebuffer to 800x600 at 32bpp and 75Hz. The 102framebuffer will use 8 MB of System RAM. hw acceleration of text and cursor 103will be enabled. 104 105Remarks 106------- 107 108If setting this parameter doesn't work (you stay in a 80x25 text-mode), 109you might need to set the "vga=<mode>" parameter too - see vesafb.txt 110in this directory. 111 112 113D. Module options 114================== 115 116The module parameters are essentially similar to the kernel 117parameters. The main difference is that you need to include a Boolean value 118(1 for TRUE, and 0 for FALSE) for those options which don't need a value. 119 120Example, to enable MTRR, include "mtrr=1". 121 122Sample Usage 123------------ 124 125Using the same setup as described above, load the module like this:: 126 127 modprobe intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1 128 129Or just add the following to a configuration file in /etc/modprobe.d/:: 130 131 options intelfb mode=800x600-32@75 vram=8 accel=1 hwcursor=1 132 133and just do a:: 134 135 modprobe intelfb 136 137 138E. Acknowledgment: 139=================== 140 141 1. Geert Uytterhoeven - his excellent howto and the virtual 142 framebuffer driver code made this possible. 143 144 2. Jeff Hartmann for his agpgart code. 145 146 3. David Dawes for his original kernel 2.4 code. 147 148 4. The X developers. Insights were provided just by reading the 149 XFree86 source code. 150 151 5. Antonino A. Daplas for his inspiring i810fb driver. 152 153 6. Andrew Morton for his kernel patches maintenance. 154 155Sylvain