VGA(3) VGA(3)
NAME
vga - VGA controller device
SYNOPSIS
bind #v /dev
/dev/vgactl
DESCRIPTION
The VGA device allows configuration of a graphics controller
on a PC. Vgactl allows control over higher-level settings
such as display height, width, depth, controller and
hardware-cursor type. Along with the I/O-port registers
provided by arch(3), it is used to implement configuration
and setup of VGA controller cards. This is usually per-
formed by vga(8).
Writing strings to vgactl configures the VGA device. The
following are valid commands.
size XxYxZ chan
Set the size of the screen image to be X pixels wide
and Y pixels high. Each pixel is Z bits as specified
by chan, whose format is described in image(6).
actualsize XxY
Set the physical size of the display to be X pixels
wide by Y pixels high. This message is optional; if
this size is smaller than that specified in the size
message, the screen will pan to follow the mouse. This
is useful on systems with small displays, such as lap-
tops.
type ctlr
Set the type of VGA controller being used. Ctlr is one
of ark200pv, clgd542x, clgd546x, ct65545, cyber938x,
hiqvideo, mach64xx, mga2164w, neomagic, s3, and t2r4.
Note that this list does not indicate the full set of
VGA chips supported. For example, s3 includes the
86C801/5, 86C928, Vision864, and Vision964. It is the
job of vga(8) to recognize which particular chip is
being used and to initialize it appropriately.
hwgc gc
Set the type of hardware graphics cursor being used.
Gc is one of ark200pvhwgc, bt485hwgc, clgd542xhwgc,
clgd546xhwgc, ct65545hwgc, cyber938xhwgc, hiqvideohwgc,
mach64xxhwgc, mga2164whwgc, neomagichwgc, rgb524hwgc,
s3hwgc, t2r4hwgc, tvp3020hwgc, and tvp3026hwgc. A
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VGA(3) VGA(3)
value of off disables the cursor. There is no software
cursor.
palettedepth d
Set the number of bits of precision used by the VGA
palette to d, which must be either 6 or 8.
blank
Blank the screen. This consists of setting the hard-
ware color map to all black as well as, on some con-
trollers, setting the VGA hsync and vsync signals so as
to turn off VESA DPMS-compliant monitors. The screen
also blanks after 30 minutes of inactivity. The screen
can be unblanked by moving the mouse.
blanktime minutes
Set the timeout before the screen blanks; the default
is 30 minutes. If minutes is zero, blanking is dis-
abled.
hwaccel mode
Depending on whether mode is on or off, enable or dis-
able whether hardware acceleration (currently for rect-
angle filling and moving) used by the graphics engine.
The default setting is on.
hwblank mode
Depending on whether mode is on or off, enable or dis-
able the use of DPMS blanking (see blank above).
linear size align
Use a linear screen aperture of size size aligned on an
align-byte boundary.
drawinit
Initialize the graphics hardware. This must be sent
after setting the type.
Reading vgactl returns the current settings, one per line.
EXAMPLES
The following disables hardware acceleration.
echo -n 'hwaccel off' >/dev/vgactl
SOURCE
/sys/src/9/pc/devvga.c
SEE ALSO
arch(3), vga(8)
BUGS
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VGA(3) VGA(3)
There should be support for the hardware graphics cursor on
the clgd54[23]x VGA controller chips.
The hardware graphics cursor on the et4000 does not work in
2x8-bit mode.
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