VGA(8) VGA(8)
NAME
vga - configure a VGA card
SYNOPSIS
aux/vga [ -BcdilpvV ] [ -b bios-string ] [ -m monitor ] [ -t
tilt ] [ -x file ] [ mode [ size ] ]
DESCRIPTION
Vga configures a VGA controller for various display sizes
and depths. Using the monitor type specified in
/env/monitor (default vga) and the mode given as argument
(default 640x480x1), vga uses the database of known VGA con-
trollers and monitors in /lib/vgadb (see vgadb(6)) to con-
figure the display via the devices provided by vga(3). The
options are:
-b bios-string
use the VGA database entry corresponding to bios-string
(e.g. 0xC0045="Stealth 64 DRAM Vers. 2.02") rather than
looking for identifying strings in the BIOS memory.
-B dump the BIOS memory (in hex) to standard output and
exit.
-c disable the use of the hardware graphics cursor.
-d include the color palette in whatever actions are per-
formed, usually printing the contents.
-i when used with -p display the register values that will
be loaded.
-l load the desired mode.
-m monitor
override the /env/monitor value. /env/monitor is usu-
ally set by including it in the plan9.ini file read by
the PC boot program.
-p print the current or expected register values at appro-
priate points depending on other options.
-v print a trace of the functions called.
-V print a verbose trace of the functions called.
-t can be used to change the tilt of the screen. The
value is one of none, left, inverted and right. See
vga(3).
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VGA(8) VGA(8)
-x file
use file as the VGA database rather than /lib/vgadb.
Mode is of the form XxYxZ[,S][,#N] , where X, Y, and Z are
numbers specifying the display height, width, and depth
respectively. S is scaling mode, either scalefull or
scaleaspect; not specifying it disables scaling altogether.
#N is used to switch to a specific display using its index
N.
The mode must appear in /lib/vgadb as a value for one of the
monitor entries. The usual modes are 640x480x[18],
800x600x[18], 1024x768x[18][i], 1280x1024x[18][i],
1376x1024x8, and 1600x1200x8. A trailing `i' indicates
interlaced operation. The default mode is 640x480x8. Size
is of the form X x Y and configures the display to have a
virtual screen of the given size.
Using the monitor name vesa instructs vga to use VESA BIOS
calls to configure the display. Also, if our VGA controller
can't be found in vgadb, vga will try the VESA calls. There
are no entries for the vesa monitor in vgadb. For a list of
available VESA modes and connected displays, use
aux/vga -m vesa -p
Loading the special mode text:
aux/vga -l text
switches out of graphics mode back into text mode. It uses
the VESA BIOS.
EXAMPLES
Change the display resolution:
aux/vga -l 1600x1200x8
Show connected and active displays:
aux/vga -m vesa -p | grep dsp
Switch to display 4 and load a specific mode:
aux/vga -m vesa -l '1920x1080x16,#4'
Print the current VGA controller registers. It is usually
best to redirect the output of a -p command to a file to
prevent confusion caused by using the VGA controller while
trying to dump its state:
aux/vga -p >/tmp/x
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VGA(8) VGA(8)
Force the VGA controller to a known state:
aux/vga -m vga -l
Print the current VGA controller state and what would be
loaded into it for a new resolution, but don't do the load:
aux/vga -ip 1376x1024x8 >/tmp/x
FILES
/env/monitor display type (default vga).
/lib/vgadb VGA configuration file.
SOURCE
/sys/src/cmd/aux/vga
SEE ALSO
vga(3), vgadb(6),
BUGS
Aux/vga makes every effort possible to verify that the mode
it is about to load is valid and will bail out with an error
message before setting any registers if it encounters a
problem. However, things can go wrong, especially when
playing with a new VGA controller or monitor setting. It is
useful in such cases to have the above command for setting
the controller to a known state at your fingertips.
Scaling modes currently work with Intel and NVIDIA video
adapters only, using VESA. Intel doesn't support scaleaspect
mode.
Display switching currently works with Intel video adapters
only, using VESA.
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