Provided by: fbset_2.1-31_amd64 bug


       fbset - show and modify frame buffer device settings


       fbset [options] [mode]


       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 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/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

                     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 externally
                     instead. Note that this option may not be supported by  every  frame  buffer

              -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 custom 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 respectively. 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 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 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


       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




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


       Geert Uytterhoeven <>

       Roman Zippel <>
              man files