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 initialise 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 re-enabled. 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.

vbetool 0.2                                     31 December 2004                                      VBETOOL(8)