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 de‐
       vice. 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>,  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 op‐
                     tion 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/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 provided ex‐
                     ternally instead. Note that this option may not  be  supported  by
                     every frame buffer device

              -sync <value>
                     set  custom  sync flags. If specified, this value is bitwise or-ed
                     to the other sync flags. This is useful for drivers that use  cus‐
                     tom sync flags

              -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 respec‐
                     tively. These two frames will be displayed alternating,  this  way
                     twice  the  lines  can be displayed and the vertical frequency 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 dis‐
                     played 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 specification  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 horizontally
                     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)

Linux Frame Buffer Device Configuration Version 2.1 (23/06/1999)
(C) Copyright 1995-1999 by Geert Uytterhoeven


Usage: fbset [options] [mode]

Valid options:
  General options:
    -h, --help         : display this usage information
    --test             : don't change, just test whether the mode is valid
    -s, --show         : display video mode settings
    -i, --info         : display all frame buffer information
    -v, --verbose      : verbose mode
    -V, --version      : print version information
    -x, --xfree86      : XFree86 compatibility mode
    -a, --all          : change all virtual consoles on this device
  Frame buffer special device nodes:
    -fb <device>       : processed frame buffer device
                         (default is /dev/fb0)
  Video mode database:
    -db <file>         : video mode database file
                         (default is /etc/fb.modes)
  Display geometry:
    -xres <value>      : horizontal resolution (in pixels)
    -yres <value>      : vertical resolution (in pixels)
    -vxres <value>     : virtual horizontal resolution (in pixels)
    -vyres <value>     : virtual vertical resolution (in pixels)
    -depth <value>     : display depth (in bits per pixel)
    -nonstd <value>    : select nonstandard video mode
    -g, --geometry ... : set all geometry parameters at once
    -match             : set virtual vertical resolution by virtual resolution
  Display timings:
    -pixclock <value>  : pixel clock (in picoseconds)
    -left <value>      : left margin (in pixels)
    -right <value>     : right margin (in pixels)
    -upper <value>     : upper margin (in pixel lines)
    -lower <value>     : lower margin (in pixel lines)
    -hslen <value>     : horizontal sync length (in pixels)
    -vslen <value>     : vertical sync length (in pixel lines)
    -t, --timings ...  : set all timing parameters at once
  Display flags:
    -accel <value>     : hardware text acceleration enable (false or true)
    -hsync <value>     : horizontal sync polarity (low or high)
    -vsync <value>     : vertical sync polarity (low or high)
    -csync <value>     : composite sync polarity (low or high)
    -gsync <value>     : synch on green (false or true)
    -extsync <value>   : external sync enable (false or true)
    -sync <value>      : custom (driver specific) sync value
    -bcast <value>     : broadcast enable (false or true)
    -laced <value>     : interlace enable (false or true)
    -double <value>    : doublescan enable (false or true)
    -rgba <r,g,b,a>    : recommended length of color entries
    -grayscale <value> : grayscale enable (false or true)
  Display positioning:
    -move <direction>  : move the visible part (left, right, up or down)
    -step <value>      : step increment (in pixels or pixel lines)
                         (default is 8 horizontal, 2 vertical)