fbset(1)						     Linux frame buffer utils							  fbset(1)

NAME

       fbset - show and modify frame buffer device settings

SYNOPSIS

       fbset [options] [mode]

DESCRIPTION

       fbset  is  a system utility to show or change the settings of the frame buffer device. The frame buffer device provides a simple and unique
       interface to access different kinds of graphic displays.

       Frame buffer devices are accessed via special device nodes located in the /dev directory. The naming  scheme  for  these  nodes	is  always
       fb/<n> or fb<n>, where n is the number of the used frame buffer device.

       fbset  uses  an	own  video mode database located in /etc/fb.modes. An unlimited number of video modes can be defined in this database. For
       further information see fb.modes(5).

OPTIONS

       If no option is given, fbset will display the current frame buffer settings.

       General options:

	      --help, -h
		     display an usage information

	      --test don't change, just test whether the mode is valid

	      --show, -s
		     display the video mode settings. This is default if no further option or only a frame buffer device via -fb is given

	      --info, -i
		     display all available frame buffer information

	      --verbose, -v
		     display information what fbset is currently doing

	      --version, -V
		     display the version information about fbset

	      --xfree86, -x
		     display the timing information as it's needed by XFree86

       Frame buffer device nodes:

	      --all, -a
		     change all virtual consoles on this device

	      -fb <device>
		     device gives the frame buffer device node. If no device via -fb is given, /dev/fb/0 or /dev/fb0 is used

       Video mode database:

	      -db <file>
		     set an alternative video mode database file (default is /etc/fb.modes), see also fb.modes(5)

       Display bitfield colors:

	      -rgba <red,green,blue,alpha>
		     each in length or length/offset color format

       Display geometry:

	      -xres <value>
		     set visible horizontal resolution (in pixels)

	      -yres <value>
		     set visible vertical resolution (in pixels)

	      -vxres <value>
		     set virtual horizontal resolution (in pixels)

	      -vyres <value>
		     set virtual vertical resolution (in pixels)

	      -depth <value>
		     set display depth (in bits per pixel)

	      -nonstd <value>
		     select nonstandard video mode

	      --geometry, -g ...
		     set all geometry parameters at once in the order <xres> <yres> <vxres> <vyres> <depth>, e.g.  -g 640 400 640 400 4

	      -match
		     make the physical resolution match the virtual resolution

       Display timings:

	      -pixclock <value>
		     set the length of one pixel (in picoseconds). Note that the frame buffer device may only support some pixel lengths

	      -left <value>
		     set left margin (in pixels)

	      -right <value>
		     set right margin (in pixels)

	      -upper <value>
		     set upper margin (in pixel lines)

	      -lower <value>
		     set lower margin (in pixel lines)

	      -hslen <value>
		     set horizontal sync length (in pixels)

	      -vslen <value>
		     set vertical sync length (in pixel lines)

	      --timings, -t ...
		     set all timing parameters at once in the order <pixclock> <left> <right> <upper> <lower> <hslen> <vslen>, e.g.  -t  35242	64
		     96 35 12 112 2

       Display flags:

	      -accel {false|true}
		     set hardware text acceleration enable

	      -hsync {low|high}
		     set the horizontal sync polarity

	      -vsync {low|high}
		     set the vertical sync polarity

	      -csync {low|high}
		     set the composite sync polarity

	      -gsync {false|true}
		     set synch on green

	      -extsync {false|true}
		     enable  or disable external resync. If enabled the sync timings are not generated by the frame buffer device and must be pro-
		     vided externally instead. Note that this option may not be supported by every frame buffer device

	      -bcast {false|true}
		     enable or disable broadcast modes. If enabled the frame buffer generates the exact timings for several broadcast modes  (e.g.
		     PAL or NTSC). Note that this option may not be supported by every frame buffer device

	      -laced {false|true}
		     enable  or disable interlace. If enabled the display will be split in two frames, each frame contains only even and odd lines
		     respectively. These two frames will be displayed alternating, this way twice the lines can be displayed and the vertical fre-
		     quency for the monitor stays the same, but the visible vertical frequency gets halved

	      -double {false|true}
		     enable  or disable doublescan. If enabled every line will be displayed twice and this way the horizontal frequency can easily
		     be doubled, so that the same resolution can be displayed on different monitors, even if the horizontal  frequency	specifica-
		     tion differs. Note that this option may not be supported by every frame buffer device

       Display positioning:

	      -move {left|right|up|down}
		     move the visible part of the display in the specified direction

	      -step <value>
		     set  step size for display positioning (in pixels or pixel lines), if -step is not given display will be moved 8 pixels hori-
		     zontally or 2 pixel lines vertically

EXAMPLE

       To set the used video mode for X insert the following in rc.local:

	      fbset -fb /dev/fb0 640x480-60

       and make the used frame buffer device known to X:

	      export FRAMEBUFFER=/dev/fb0

FILES

       /dev/fb*
       /etc/fb.modes

SEE ALSO

       fb.modes(5), fbdev(4), /usr/share/doc/fbset/FAQ.gz

AUTHORS

       Geert Uytterhoeven <Geert.Uytterhoeven@cs.kuleuven.ac.be>

       Roman Zippel <zippel@fh-brandenburg.de>
	      man files

2.1								    2010-04-12								  fbset(1)