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> 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).


If no option is given, fbset will display the current frame buffer settings.

General options:


display an usage information


don’t change, just test whether the mode is valid


display the video mode settings. This is default if no further option or only a frame buffer device via −fb is given


display all available frame buffer information


display information what fbset is currently doing


display the version information about fbset


display the timing information as it’s needed by XFree86

Frame buffer device nodes:


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


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. −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 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


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 <Geert.Uytterhoeven@cs.kuleuven.ac.be>
Roman Zippel <zippel@fh-brandenburg.de>

man files


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.