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 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 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 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
