fbset
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 pro
vides 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 informa
tion
--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.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 pix
els)
-yres <value>
set visible vertical resolution (in pixels)
-vxres <value>
set virtual horizontal resolution (in pix
els)
-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)
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:
-accel {false|true}
set hardware text acceleration
enable
-hsync {low|high}
set the horizontal sync polar
ity
-vsync {low|high}
set the vertical sync polarity
-csync {low|high}
set the composite sync polar
ity
-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 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
-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 dis
played on different monitors,
even if the horizontal fre
quency 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 vga
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)
AUTHORS
Geert Uytterhoeven <Geert.Uytterho
even@cs.kuleuven.ac.be>
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