vga - configure a VGA card
aux/vga [ -cdilmpv ] [ mode ]
Aux/vga configures a VGA controller for various display sizes and depths. Using the moni-
tor type specified in /env/monitor (default vga) and the mode given as argument (default
640x480x1), aux/vga uses the database of known VGA controllers and monitors in /lib/vgadb
(see vgadb(6)) to configure the display via the devices provided by vga(3). The options
-c force the use of the software cursor even if the VGA card is capable of using a
hardware graphics cursor.
-d include the color palette in whatever actions are performed, usually printing the
-i when used with -p display the register values that will be loaded.
-l load the desired mode.
override the /env/monitor value. /env/monitor is usually set by including it in
the plan9.ini file read by the PC boot program b.com(8).
-p print the current or expected register values at appropriate points depending on
-v print a trace of the functions called.
Mode is of the form XxYxZ , where X, Y, and Z are numbers specifying the display height,
width, and depth respectively. The mode must appear in /lib/vgadb as a value for one of
the monitor entries. The usual modes are 640x480x, 800x600x, 1024x768x[i],
1280x1024x[i], 1376x1024x8, and 1600x1200x8. A trailing indicates interlaced opera-
Change the display resolution:
aux/vga -l 1600x1200x8
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 try-
ing to dump its state:
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 resolu-
tion, but don't do the load:
aux/vga -ip 1376x1024x8>/tmp/x
display type (default vga).
VGA configuration file.
vga(3), vgadb(6), b.com(8)
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.