NAME

       vbetool - run real-mode video BIOS code to alter hardware state

SYNOPSIS

       vbetool         [[vbestate         save|restore]|[vbemode         set|get]|[vgamode]|[dpms
       on|off|standby|suspend|reduced]|[post         [romfile]]|[vgastate          on|off]|[vbefp
       panelid|panelsize|getbrightness|setbrightness|invert]]

DESCRIPTION

       vbetool uses lrmi in order to run code from the video BIOS. Currently, it is able to alter
       DPMS states, save/restore video card state and attempt to initialize the video  card  from
       scratch.

OPTIONS

       vbetool takes the following options:

       vbestate
              vbetool will use the VESA 0x4f0f extensions to save or restore hardware state. This
              will be sent to or read from stdin. This information is highly hardware specific  -
              do  not  attempt to restore state saved from a different machine. This command will
              not work unless you are at a text console, as it interferes badly with X.

       dpms   vbetool will use the VESA 0x4f10 extensions to alter the power management state  of
              your screen. "On", "off", "standby", "suspend" and "reduced" are acceptable further
              options and determine which state will be activated.

       vbemode
              vbetool will get or set the current VESA mode. "get" will return the  current  mode
              number on stdout - "set" will set the mode to the next argument.

       vgamode
              vbetool will set the legacy VGA mode to the following numeric argument.

       post   vbetool will attempt to run BIOS code located at c000:0003. This is the code run by
              the system BIOS at boot in order to intialise the video hardware. Note that on some
              machines  (especially laptops), not all of this code is present after system boot -
              as a result, executing this command may result in undefined behaviour. This command
              must  be run from a text console, as it will otherwise interfere with the operation
              of X. This command takes an optional argument which  is  the  location  of  a  file
              containing  a ROM image. If provided, this image will be mapped to the c000 segment
              and used instead of the system's video BIOS.

       vgastate
              vbetool will enable or disable the current video card. On most hardware,  disabling
              will  cause  the  hardware  to  stop responding until it is reenabled. You probably
              don't want to do this if you're using a framebuffer.

       vbefp  vbetool will execute a VESA flat panel interface call.

              panelid will provide information about the panel

              panelsize will provide the size of the panel

              getbrightness will provide the current screen brightness as an integer

              setbrightness accepts an integer as an argument and will set the screen  brightness
              to that

              invert will invert the colours of the screen

BUGS

       Switching dpms modes may interact badly with X on some systems.

       The vbestate command may behave in strange ways.

       The  post  command  may result in the execution of arbitrary code that happens to be lying
       around in the area where chunks of your video BIOS used to be.

       The VESA specification does not require that "vbemode get" provides the  correct  mode  if
       the current mode was set via some means other than the VESA BIOS extensions.

       The  VESA  flat  panel  interface  ceased  development at the proposal stage.  panelid and
       panelsize will work on  many  machines,  but  the  other  arguments  are  unlikely  to  be
       implemented on available hardware.

AUTHOR

       vbetool was written by Matthew Garrett <mjg59@srcf.ucam.org>, based on code from read-edid
       by John Fremlin <john@fremlin.de>, LRMI (http://sourceforge.net/projects/lrmi/) and  XFree
       (http://www.xfree86.org).  It  is  released  under  the  terms  of  the GNU General Public
       License.