VIRTUAL
TERMINALS(4) BSD Kernel Interfaces Manual VIRTUAL TERMINALS(4)
NAME
vt -- virtual terminal console driver
SYNOPSIS
options TERMINAL_KERN_ATTR=_attribute_
options TERMINAL_NORM_ATTR=_attribute_
options VT_MAXWINDOWS=N
options VT_ALT_TO_ESC_HACK=1
options VT_TWOBUTTON_MOUSE
options VT_FB_DEFAULT_WIDTH=X
options VT_FB_DEFAULT_HEIGHT=Y
options SC_NO_CUTPASTE
device vt
In loader.conf(5):
hw.vga.textmode=1
kern.vty=vt
kern.vt.fb.default_mode="<X>x<Y>"
kern.vt.fb.modes.<connector>="<X>x<Y>"
In loader.conf(5) or sysctl.conf(5):
kern.vt.kbd_halt=1
kern.vt.kbd_poweroff=1
kern.vt.kbd_reboot=1
kern.vt.kbd_debug=1
kern.vt.kbd_panic=0
DESCRIPTION
The vt device provides multiple virtual terminals with an extensive feature set:
Unicode UTF-8 text with double-width characters.
Large font maps in graphics mode, including support for Asian character sets.
Graphics-mode consoles.
Integration with KMS (Kernel Mode Setting) video drivers for switching between the X Window System and virtual terminals.
Virtual Terminals
Multiple virtual terminals are provided on a single computer. Up to sixteen virtual terminals can be defined. A single virtual terminal is
connected to the screen and keyboard at a time. Key combinations are used to select a virtual terminal. Alt-F1 through Alt-F12 correspond
to the first twelve virtual terminals. If more than twelve virtual terminals are created, Shift-Alt-F1 through Shift-Alt-F4 are used to
switch to the additional terminals.
Copying and Pasting Text with a Mouse
Copying and pasting text from the screen with a mouse is supported. Press and hold down mouse button 1, usually the left button, while mov-
ing the mouse to select text. Selected text is highlighted with reversed foreground and background colors. To select more text after
releasing mouse button 1, press mouse button 3, usually the right button. To paste text that has been selected, press mouse button 2, usu-
ally the middle button. The text is entered as if it were typed at the keyboard. The VT_TWOBUTTON_MOUSE kernel option can be used with mice
that only have two buttons. Setting this option makes the second mouse button into the paste button. See moused(8) for more information.
Scrolling Back
Output that has scrolled off the screen can be reviewed by pressing the Scroll Lock key, then scrolling up and down with the arrow keys. The
Page Up and Page Down keys scroll up or down a full screen at a time. The Home and End keys jump to the beginning or end of the scrollback
buffer. When finished reviewing, press the Scroll Lock key again to return to normal use.
DRIVER CONFIGURATION
Kernel Configuration Options
These kernel options control the vt driver.
TERMINAL_NORM_ATTR=attribute
TERMINAL_KERN_ATTR=attribute
These options allow changing the default colors used for normal and kernel text. Available colors are defined in <sys/terminal.h>.
See EXAMPLES below.
VT_MAXWINDOWS=N
Set the number of virtual terminals to be created to N. The value defaults to 12.
VT_ALT_TO_ESC_HACK=1
When the Alt key is held down while pressing another key, send an ESC sequence instead of the Alt key.
VT_TWOBUTTON_MOUSE
If defined, swap the functions of mouse buttons 2 and 3. In effect, this makes the right-hand mouse button perform a paste. These
options are checked in the order shown.
SC_NO_CUTPASTE
Disable mouse support.
VT_FB_DEFAULT_WIDTH=X
Set the default width to X.
VT_FB_DEFAULT_HEIGHT=Y
Set the default height to Y.
BACKWARDS COMPATIBILITY
Several options are provided for compatibility with the previous console device, sc(4). These options will be removed in a future FreeBSD
version.
vt Option Name sc Option Name
TERMINAL_KERN_ATTR SC_KERNEL_CONS_ATTR
TERMINAL_NORM_ATTR SC_NORM_ATTR
VT_TWOBUTTON_MOUSE SC_TWOBUTTON_MOUSE
VT_MAXWINDOWS MAXCONS
none SC_NO_CUTPASTE
START-UP OPERATION WITH X86 BIOS SYSTEMS
The computer BIOS starts in text mode, and the FreeBSD loader(8) runs, loading the kernel. If hw.vga.textmode is set, the system remains in
text mode. Otherwise, vt switches to 640x480x16 VGA mode using vt_vga. If a KMS (Kernel Mode Setting) video driver is available, the dis-
play is switched to high resolution and the KMS driver takes over. When a KMS driver is not available, vt_vga remains active.
LOADER TUNABLES
These settings can be entered at the loader(8) prompt or in loader.conf(5).
hw.vga.textmode
Set to 1 to use virtual terminals in text mode instead of graphics mode. Features that require graphics mode, like loadable fonts,
will be disabled.
kern.vty
Set this value to 'vt' or 'sc' to override the default driver used for the system console. By default, sc(4) is used on computers
that boot from BIOS, and vt is used on computers that boot from UEFI.
kern.vt.fb.default_mode
Set this value to a graphic mode to override the default mode picked by the vt backend. The mode is applied to all output connec-
tors. This is currently only supported by the vt_fb backend when it's paired with a KMS video driver.
kern.vt.fb.modes.connector_name
Set this value to a graphic mode to override the default mode picked by the vt backend. This mode is applied to the output connector
connector_name only. It has precedence over kern.vt.fb.default_mode. The names of available connector names can be found in dmesg(8)
after loading the KMS driver. It will contain a list of connectors and their associated tunables. This is currently only supported
by the vt_fb backend when it's paired with a KMS video driver.
KEYBOARD SYSCTL TUNABLES
These settings control whether certain special key combinations are enabled or ignored. The specific key combinations can be configured by
using a keymap(5) file.
These settings can be entered at the loader(8) prompt or in loader.conf(5) and can also be changed at runtime with the sysctl(8) command.
kern.vt.kbd_halt
Enable halt keyboard combination.
kern.vt.kbd_poweroff
Enable power off key combination.
kern.vt.kbd_reboot.
Enable reboot key combination, usually Ctrl+Alt+Del.
kern.vt.kbd_debug
Enable debug request key combination, usually Ctrl+Alt+Esc.
kern.vt.kbd_panic
Enable panic key combination.
FILES
/dev/console
/dev/consolectl
/dev/ttyv* virtual terminals
/etc/ttys terminal initialization information
/usr/share/vt/fonts/*.fnt
console fonts
/usr/share/vt/keymaps/*.kbd
keyboard layouts
EXAMPLES
This example changes the default color of normal text to green on a black background, or black on a green background when reversed. Note
that white space cannot be used inside the attribute string because of the current implementation of config(8).
options TERMINAL_NORM_ATTR=(FG_GREEN|BG_BLACK)
This line changes the default color of kernel messages to be bright red on a black background, or black on a bright red background when
reversed.
options TERMINAL_KERN_ATTR=(FG_LIGHTRED|BG_BLACK)
To set a 1024x768 mode on all output connectors, put the following line in /boot/loader.conf:
kern.vt.fb.default_mode="1024x768"
To set a 800x600 only on a laptop builtin screen, use the following line instead:
kern.vt.fb.modes.LVDS-1="800x600"
The connector name was found in dmesg(8):
info: [drm] Connector LVDS-1: get mode from tunables:
info: [drm] - kern.vt.fb.modes.LVDS-1
info: [drm] - kern.vt.fb.default_mode
SEE ALSO
kbdcontrol(1), login(1), vidcontrol(1), atkbd(4), atkbdc(4), keyboard(4), screen(4), splash(4), syscons(4), ukbd(4), kbdmap(5), rc.conf(5),
ttys(5), config(8), getty(8), kbdmux(8), kldload(8), moused(8), vtfontcvt(8)
HISTORY
The vt driver first appeared in FreeBSD 9.3.
AUTHORS
The vt device driver was developed by Ed Schouten <ed@FreeBSD.org>, Ed Maste <emaste@FreeBSD.org>, and Aleksandr Rybalko <ray@FreeBSD.org>,
with sponsorship provided by the FreeBSD Foundation. This manual page was written by Warren Block <wblock@FreeBSD.org>.
CAVEATS
Paste buffer size is limited by the system value {MAX_INPUT}, the number of bytes that can be stored in the terminal input queue, usually
1024 bytes (see termios(4)).
BSD
October 20, 2014 BSD