fbset(8)                   Linux frame buffer utils                   fbset(8)

       fbset - show and modify frame buffer device settings

       fbset [options] [mode]

       This documentation is out of date!!

       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>,
       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).

       If no option is given, fbset will display the current frame buffer set-

       General options:

              --help, -h
                     display an usage information

              --now, -n
                     change the video mode immediately.  If  no  frame  buffer
                     device  is  given via -fb , then this option is activated
                     by default

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

              --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:

              -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 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)

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

                     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

              -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.   -g
                     35242 64 96 35 12 112 2

       Display flags:

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

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

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

              -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  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 dis-
                     played alternating, this way twice the lines can be  dis-
                     played  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  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 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

              -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

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

              fbset -fb /dev/fb0 vga

       and make the used frame buffer device known to X:

              export FRAMEBUFFER=/dev/fb0


       fb.modes(5), fbdev(4)

       Geert Uytterhoeven <>

       Roman Zippel <>
              man files

local                              July 1998                          fbset(8)