VIDCONTROL(1) FreeBSD General Commands Manual VIDCONTROL(1)
NAME
vidcontrol - system console control and configuration utility
SYNOPSIS
vidcontrol [-CdHLPpx] [-b color] [-c appearance] [-E emulator] [-f
[[size] file]] [-g geometry] [-h size]
[-i active | adapter | mode] [-l screen_map] [-M char]
[-m on | off] [-r foreground background] [-S on | off]
[-s number] [-T xterm | cons25] [-t N | off] [mode]
[foreground [background]] [show]
DESCRIPTION
The vidcontrol utility is used to set various options for the syscons(4)
or vt(4) console driver, such as video mode, colors, cursor shape, screen
output map, font, and screen saver timeout. Only a small subset of
options is supported by vt(4). Unsupported options lead to error
messages, typically including the text "Inappropriate ioctl for device".
The following command line options are supported:
mode Select a new video mode. The modes currently recognized are:
80x25, 80x30, 80x43, 80x50, 80x60, 132x25, 132x30, 132x43,
132x50, 132x60, VGA_40x25, VGA_80x25, VGA_80x30, VGA_80x50,
VGA_80x60, VGA_90x25, VGA_90x30, VGA_90x43, VGA_90x50, VGA_90x60,
EGA_80x25, EGA_80x43, VESA_132x25, VESA_132x43, VESA_132x50,
VESA_132x60. The raster text mode VESA_800x600 can also be
chosen. Alternatively, a mode can be specified with its number
by using a mode name of the form MODE_<NUMBER>. A list of valid
mode numbers can be obtained with the -i mode option. See Video
Mode Support below.
foreground [background]
Change colors when displaying text. Specify the foreground color
(e.g., "vidcontrol white"), or both a foreground and background
colors (e.g., "vidcontrol yellow blue"). Use the show command
below to see available colors.
show See the supported colors on a given platform.
-b color
Set border color to color. This option may not be always
supported by the video driver.
-C Clear the history buffer.
-c setting[,setting ...]
Change the cursor appearance. The change is specified by a non-
empty comma-separated list of settings. Each setting overrides
or modifies previous ones in left to right order.
The following override settings are available:
normal Set to a block covering 1 character cell, with a
configuration-dependent coloring that should be at worst
inverse video.
destructive
Set to a blinking sub-block with height scanlines
starting at base. The name "destructive" is bad for
backwards compatibility. This setting should not force
destructiveness, and it now only gives destructiveness in
some configurations (typically for hardware cursors in
text mode). Blinking limits destructiveness. This
setting should now be spelled normal,blink,noblock. A
non-blinking destructive cursor would be unusable, so old
versions of vidcontrol did not support it, and this
version does not have an override for it.
base=value, height=value
Set the specified scanline parameters. These parameters
are only active in noblock mode. value is an integer in
any base supported by strtol(3). Setting height to 0
turns off the cursor in noblock mode. Negative values
are silently ignored. Positive values are clamped to fit
in the character cell when the cursor is drawn.
The following modifier settings are available:
blink, noblink
Set or clear the blinking attribute. This is not quite
backwards compatible. In old versions of vidcontrol,
blink was an override to a blinking block.
block, noblock
Set or clear the block attribute. This attribute is the
inverse of the flag CONS_CHAR_CURSOR in the
implementation. It deactivates the scanline parameters,
and expresses a preference for using a simpler method of
implementation. Its inverse does the opposite. When the
scanline parameters give a full block, this attribute
reduces to a method selection bit. The block method
tends to give better coloring.
hidden, nohidden
Set or clear the hidden attribute.
The following (non-sticky) flags control application of the
settings:
charcolors
Apply base and height to the (character) cursor's list of
preferred colors instead of its shape. Beware that the
color numbers are raw VGA palette indexes, not ANSI color
numbers. The indexes are reduced mod 8, 16 or 256, or
ignored, depending on the video mode and renderer.
mousecolors
Colors for the mouse cursor in graphics mode. Like
charcolors, except there is no preference or sequence;
base gives the mouse border color and height gives the
mouse interior color. Together with charcolors, this
gives 2 selection bits which select between only 3 of 4
sub-destinations of the 4 destinations selected by
default and local (by ignoring mousecolors if charcolors
is also set).
default
Apply the changes to the default settings and then to the
active settings, instead of only to the active settings.
Together with local, this gives 2 selection bits which
select between 4 destinations.
shapeonly
Ignore any changes to the block and hidden attributes.
local Apply the changes to the current vty. The default is to
apply them to a global place and copy from there to all
vtys.
reset Reset everything. The default is to not reset. When the
local parameter is specified, the current local settings
are reset to default local settings. Otherwise, the
current global settings are reset to default global
settings and then copied to the current and default
settings for all vtys.
show Show the current changes.
-d Print out current output screen map.
-E emulator
Set the terminal emulator to emulator.
-e Show the active and available terminal emulators.
-f [[size] file]
Load font file for size (currently, only 8x8, 8x14 or 8x16). The
font file can be either uuencoded or in raw binary format. You
can also use the menu-driven vidfont(1) command to load the font
of your choice.
Size may be omitted, in this case vidcontrol will try to guess it
from the size of font file.
When using vt(4) both size and file can be omitted, and the
default font will be loaded.
Note that older video cards, such as MDA and CGA, do not support
software font. See also Video Mode Support and EXAMPLES below
and the man page for either syscons(4) or vt(4) (depending on
which driver you use).
-g geometry
Set the geometry of the text mode for the modes with selectable
geometry. Currently only raster modes, such as VESA_800x600,
support this option. See also Video Mode Support and EXAMPLES
below.
-h size
Set the size of the history (scrollback) buffer to size lines.
-i active
Shows the active vty number.
-i adapter
Shows info about the current video adapter.
-i mode
Shows the possible video modes with the current video hardware.
-l screen_map
Install screen output map file from screen_map. See also
syscons(4) or vt(4) (depending on which driver you use).
-L Install default screen output map.
-M char
Sets the base character used to render the mouse pointer to char.
-m on | off
Switch the mouse pointer on or off. Used together with the
moused(8) daemon for text mode cut & paste functionality.
-p Capture the current contents of the video buffer corresponding to
the terminal device referred to by standard input. The
vidcontrol utility writes contents of the video buffer to the
standard output in a raw binary format. For details about that
format see Format of Video Buffer Dump below.
-P Same as -p, but dump contents of the video buffer in a plain text
format ignoring nonprintable characters and information about
text attributes.
-H When used with -p or -P, it instructs vidcontrol to dump full
history buffer instead of visible portion of the video buffer
only.
-r foreground background
Change reverse mode colors to foreground and background.
-S on | off
Turn vty switching on or off. When vty switching is off,
attempts to switch to a different virtual terminal will fail.
(The default is to permit vty switching.) This protection can be
easily bypassed when the kernel is compiled with the DDB option.
However, you probably should not compile the kernel debugger on a
box which is supposed to be physically secure.
-s number
Set the active vty to number.
-T xterm | cons25
Switch between xterm and cons25 style terminal emulation.
-t N | off
Set the screensaver timeout to N seconds, or turns it off.
-x Use hexadecimal digits for output.
Video Mode Support
Note that not all modes listed above may be supported by the video
hardware. You can verify which mode is supported by the video hardware,
using the -i mode option.
The VESA BIOS support must be linked to the kernel or loaded as a KLD
module if you wish to use VESA video modes or 132 column modes (see
vga(4)).
You need to compile your kernel with the VGA_WIDTH90 option if you wish
to use VGA 90 column modes (see vga(4)).
Video modes other than 25 and 30 line modes may require specific size of
font. Use -f option above to load a font file to the kernel. If the
required size of font has not been loaded to the kernel, vidcontrol will
fail if the user attempts to set a new video mode.
Modes Font size
25 line modes 8x16 (VGA), 8x14 (EGA)
30 line modes 8x16
43 line modes 8x8
50 line modes 8x8
60 line modes 8x8
It is better to always load all three sizes (8x8, 8x14 and 8x16) of the
same font.
You may set variables in /etc/rc.conf or /etc/rc.conf.local so that
desired font files will be automatically loaded when the system starts
up. See below.
If you want to use any of the raster text modes you need to recompile
your kernel with the SC_PIXEL_MODE option. See syscons(4) or vt(4)
(depending on which driver you use) for more details on this kernel
option.
Format of Video Buffer Dump
The vidcontrol utility uses the syscons(4) or vt(4) CONS_SCRSHOT ioctl(2)
to capture the current contents of the video buffer. The vidcontrol
utility writes version and additional information to the standard output,
followed by the contents of the video buffer.
VGA video memory is typically arranged in two byte tuples, one per
character position. In each tuple, the first byte will be the character
code, and the second byte is the character's color attribute.
The VGA color attribute byte looks like this:
bits# width meaning
7 <X0000000> 1 character blinking
6:4 <0XXX0000> 3 background color
3 <0000X000> 1 bright foreground color
2:0 <00000XXX> 3 foreground color
Here is a list of the three bit wide base colors:
0 Black
1 Blue
2 Green
3 Cyan
4 Red
5 Magenta
6 Brown
7 Light Grey
Base colors with bit 3 (the bright foreground flag) set:
0 Dark Grey
1 Light Blue
2 Light Green
3 Light Cyan
4 Light Red
5 Light Magenta
6 Yellow
7 White
For example, the two bytes
65 158
specify an uppercase A (character code 65), blinking (bit 7 set) in
yellow (bits 3:0) on a blue background (bits 6:4).
The vidcontrol output contains a small header which includes additional
information which may be useful to utilities processing the output.
The first 10 bytes are always arranged as follows:
Byte Range Contents
1 - 8 Literal text "SCRSHOT_"
9 File format version number
10 Remaining number of bytes in the header
Subsequent bytes depend on the version number.
Version Byte Meaning
1 11 Terminal width, in characters
12 Terminal depth, in characters
13 and up The snapshot data
So a dump of an 80x25 screen would start (in hex)
53 43 52 53 48 4f 54 5f 01 02 50 19
----------------------- -- -- -- --
| | | | ` 25 decimal
| | | `--- 80 decimal
| | `------ 2 remaining bytes of header data
| `--------- File format version 1
`------------------------ Literal "SCRSHOT_"
VIDEO OUTPUT CONFIGURATION
Boot Time Configuration
You may set the following variables in /etc/rc.conf or /etc/rc.conf.local
in order to configure the video output at boot time.
blanktime Sets the timeout value for the -t option.
font8x16, font8x14, font8x8
Specifies font files for the -f option.
scrnmap Specifies a screen output map file for the -l option.
See rc.conf(5) for more details.
Driver Configuration
The video card driver may let you change default configuration options,
such as the default font, so that you do not need to set up the options
at boot time. See video card driver manuals, (e.g., vga(4)) for details.
FILES
/usr/share/syscons/fonts/*
/usr/share/vt/fonts/* font files.
/usr/share/syscons/scrnmaps/* screen output map files (relevant
for syscons(4) only).
EXAMPLES
If you want to load /usr/share/syscons/fonts/iso-8x16.fnt to the kernel,
run vidcontrol as:
vidcontrol -f 8x16 /usr/share/syscons/fonts/iso-8x16.fnt
So long as the font file is in /usr/share/syscons/fonts (if using
syscons) or /usr/share/vt/fonts (if using vt), you may abbreviate the
file name as iso-8x16:
vidcontrol -f 8x16 iso-8x16
Furthermore, you can also omit font size "8x16":
vidcontrol -f iso-8x16
Moreover, the suffix specifying the font size can also be omitted; in
this case, vidcontrol will use the size of the currently displayed font
to construct the suffix:
vidcontrol -f iso
Likewise, you can also abbreviate the screen output map file name for the
-l option if the file is found in /usr/share/syscons/scrnmaps.
vidcontrol -l iso-8859-1_to_cp437
The above command will load
/usr/share/syscons/scrnmaps/iso-8859-1_to_cp437.scm.
The following command will set-up a 100x37 raster text mode (useful for
some LCD models):
vidcontrol -g 100x37 VESA_800x600
The following command will capture the contents of the first virtual
terminal video buffer, and redirect the output to the shot.scr file:
vidcontrol -p < /dev/ttyv0 > shot.scr
The following command will dump contents of the fourth virtual terminal
video buffer to the standard output in the human readable format:
vidcontrol -P < /dev/ttyv3
SEE ALSO
kbdcontrol(1), vidfont(1), keyboard(4), screen(4), syscons(4), vga(4),
vt(4), rc.conf(5), kldload(8), moused(8), watch(8)
The various scr2* utilities in the graphics and textproc categories of
the Ports Collection.
AUTHORS
S/ren Schmidt <sos@FreeBSD.org>
Sascha Wildner <saw@online.de>
CONTRIBUTORS
Maxim Sobolev <sobomax@FreeBSD.org>
Nik Clayton <nik@FreeBSD.org>
FreeBSD 13.1-RELEASE-p6 October 20, 2018 FreeBSD 13.1-RELEASE-p6
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