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.
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.
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.
