NAME¶
syscons
,
sc
—
the console driver
SYNOPSIS¶
options MAXCONS=N
options SC_ALT_MOUSE_IMAGE
options SC_CUT_SEPCHARS=_characters_
options SC_CUT_SPACES2TABS
options SC_DISABLE_KDBKEY
options SC_DISABLE_REBOOT
options SC_HISTORY_SIZE=N
options SC_MOUSE_CHAR=C
options SC_NO_CUTPASTE
options SC_NO_FONT_LOADING
options SC_NO_HISTORY
options SC_NO_PALETTE_LOADING
options SC_NO_SUSPEND_VTYSWITCH
options SC_NO_SYSMOUSE
options SC_PIXEL_MODE
options SC_TWOBUTTON_MOUSE
options SC_NORM_ATTR=_attribute_
options SC_NORM_REV_ATTR=_attribute_
options SC_KERNEL_CONS_ATTR=_attribute_
options SC_KERNEL_CONS_REV_ATTR=_attribute_
options SC_DFLT_FONT
makeoptions SC_DFLT_FONT=_font_name_
device sc
In
/boot/device.hints:
hint.sc.0.at="isa"
hint.sc.0.vesa_mode=0x103
In
/boot/loader.conf:
kern.vty=sc
DESCRIPTION¶
The
syscons
driver provides multiple virtual
terminals. It resembles the SCO color console driver.
The
syscons
driver is implemented on top of
the keyboard driver (
atkbd(4)) and the video card
driver (
vga(4)) and so requires both of them to
be configured in the system.
There can be only one
syscons
device defined
in the system.
Virtual Terminals¶
The
syscons
driver provides multiple virtual
terminals which appear as if they were separate terminals. One virtual
terminal is considered current and exclusively occupies the screen and the
keyboard; the other virtual terminals are placed in the background.
In order to use virtual terminals, they must be individually marked ``on'' in
/etc/ttys so that
getty(8) will recognize them to be active and run
login(1) to let the user log in to the system. By
default, only the first eight virtual terminals are activated in
/etc/ttys.
You press the
Alt
key and a switch key to
switch between virtual terminals. The following table summarizes the
correspondence between the switch key and the virtual terminal.
Alt-F1 ttyv0 Alt-F7 ttyv6 Shift-Alt-F1 ttyva
Alt-F2 ttyv1 Alt-F8 ttyv7 Shift-Alt-F2 ttyvb
Alt-F3 ttyv2 Alt-F9 ttyv8 Shift-Alt-F3 ttyvc
Alt-F4 ttyv3 Alt-F10 ttyv9 Shift-Alt-F4 ttyvd
Alt-F5 ttyv4 Alt-F11 ttyva Shift-Alt-F5 ttyve
Alt-F6 ttyv5 Alt-F12 ttyvb Shift-Alt-F6 ttyvf
You can also use the ``nscr'' key (usually the
PrintScreen
key on the AT Enhanced
keyboard) to cycle available virtual terminals.
The default number of available virtual terminals is 16. This can be changed
with the kernel configuration option
MAXCONS
(see below).
Note that the X server usually requires a virtual terminal for display purposes,
so at least one terminal must be left unused by
getty(8) so that it can be used by the X server.
Key Definitions and Function Key Strings¶
The
syscons
driver, in conjunction with the
keyboard driver, allows the user to change key definitions and function key
strings. The
kbdcontrol(1) command will load a
key definition file (known as ``keymap'' file), dump the current keymap, and
assign a string to a function key. See
keyboard(4) and
kbdmap(5) for the keymap file.
You may want to set the
keymap variable in
/etc/rc.conf.local to the desired keymap
file so that it will be automatically loaded when the system starts up.
Software Font¶
For most modern video cards, e.g., VGA, the
syscons
driver and the video card driver
allow the user to change the font used on the screen. The
vidcontrol(1) command can be used to load a font
file from
/usr/share/syscons/fonts.
The font comes in various sizes: 8x8, 8x14 and 8x16. The 8x16 font is typically
used for the VGA card in the 80-column-by-25-line mode. Other video modes may
require different font sizes. It is better to always load all three sizes of
the same font.
You may set
font8x8,
font8x14 and
font8x16 variables in
/etc/rc.conf to the desired font files so
that they will be automatically loaded when the system starts up.
Optionally you can specify a particular font file as the default. See the
SC_DFLT_FONT
option below.
Screen Map¶
If your video card does not support software fonts, you may still be able to
achieve a similar effect by re-mapping the font built into your video card.
Use
vidcontrol(1) to load a screen map file which
defines the mapping between character codes.
Mouse Support and Copy-and-Paste¶
You can use your mouse to copy text on the screen and paste it as if it was
typed by hand. You must be running the mouse daemon
moused(8) and enable the mouse cursor in the
virtual terminal via
vidcontrol(1).
Pressing mouse button 1 (usually the left button) will start selection.
Releasing button 1 will end the selection process. The selected text will be
marked by inverting foreground and background colors. You can press button 3
(usually the right button) to extend the selected region. The selected text is
placed in the copy buffer and can be pasted at the cursor position by pressing
button 2 (usually the middle button) as many times as you like.
If your mouse has only two buttons, you may want to use the
SC_TWOBUTTON_MOUSE
option below to make the
right button to paste the text. Alternatively you can make the mouse daemon
emulate the middle button. See the man page for
moused(8) for more details.
The
syscons
driver allows the user to browse
the output which has ``scrolled off'' the top of the screen.
Press the ``slock'' key (usually
ScrllLock
/
Scroll Lock
or
Pause
on many keyboards) and the terminal
is in the ``scrollback'' mode. It is indicated by the
Scroll Lock
LED. Use the arrow keys, the
Page Up/Down
keys and the
Home/End
keys to scroll buffered terminal
output. Press the ``slock'' key again to get back to the normal terminal mode.
The size of the scrollback buffer can be set by the
SC_HISTORY_SIZE
option described below.
Screen Saver¶
The
syscons
driver can be made to put up the
screen saver if the current virtual terminal is idle, that is, the user is not
typing on the keyboard nor moving the mouse. See
splash(4) and
vidcontrol(1) for more details.
DRIVER CONFIGURATION¶
Kernel Configuration Options¶
The following kernel configuration options control the
syscons
driver.
MAXCONS=N
- This option sets the number of virtual terminals to
N. The default value is 16.
SC_ALT_MOUSE_IMAGE
- This option selects the alternative way of displaying the mouse cursor in
the virtual terminal. It may be expensive for some video cards to draw the
arrow-shaped cursor, and you may want to try this option. However, the
appearance of the alternative mouse cursor may not be very appealing. Note
that if you use the
SC_NO_FONT_LOADING
option then you must also use this option if you wish to be able to use
the mouse.
SC_CUT_SEPCHARS=_characters_
- This options specifies characters that will be looked for when the driver
searches for words boundaries when doing cut operation. By default, its
value is “
\x20
” — a space
character.
SC_CUT_SPACES2TABS
- This options instructs the driver to convert leading spaces into tabs when
copying data into cut buffer. This might be useful to preserve indentation
when copying tab-indented text.
SC_DISABLE_KDBKEY
- This option disables the ``debug'' key combination (by default, it is
Alt-Esc
, or
Ctl-PrintScreen
). It will prevent users
from entering the kernel debugger (KDB) by pressing the key combination.
KDB will still be invoked when the kernel panics or hits a break point if
it is included in the kernel. If this option is not defined, this behavior
may be controlled at runtime by the sysctl(8)
variable hw.syscons.kbd_debug.
SC_DISABLE_REBOOT
- This option disables the ``reboot'' key (by default, it is
Ctl-Alt-Del
), so that the casual user
may not accidentally reboot the system. If this option is not defined,
this behavior may be controlled at runtime by the
sysctl(8) variable
hw.syscons.kbd_reboot.
SC_HISTORY_SIZE=N
- Sets the size of back scroll buffer to N
lines. The default value is 100.
SC_MOUSE_CHAR=C
- Unless the
SC_ALT_MOUSE_IMAGE
option
above is specified, the syscons
driver
reserves four consecutive character codes in order to display the mouse
cursor in the virtual terminals in some systems. This option specifies the
first character code to C to be used for
this purpose. The default value is 0xd0. A good candidate is 0x03.
SC_PIXEL_MODE
- Adds support for pixel (raster) mode console. This mode is useful on some
laptop computers, but less so on most other systems, and it adds
substantial amount of code to syscons. If this option is NOT defined, you
can reduce the kernel size a lot. See the
VESAMODE
flag below.
SC_TWOBUTTON_MOUSE
- If you have a two button mouse, you may want to add this option to use the
right button of the mouse to paste text. See
Mouse
Support and Copy-and-Paste above.
SC_NORM_ATTR=_attribute_
-
SC_NORM_REV_ATTR=_attribute_
-
SC_KERNEL_CONS_ATTR=_attribute_
-
SC_KERNEL_CONS_REV_ATTR=_attribute_
- These options will set the default colors. Available colors are defined in
<machine/pc/display.h>
.
See EXAMPLES below.
SC_DFLT_FONT
- This option will specify the default font. Available fonts are: iso, iso2,
koi8-r, koi8-u, cp437, cp850, cp865, cp866 and cp866u. 16-line, 14-line
and 8-line font data will be compiled in. Without this option, the
syscons
driver will use whatever font
is already loaded in the video card, unless you explicitly load a software
font at startup. See
EXAMPLES below.
SC_NO_SUSPEND_VTYSWITCH
- This option, which is also available as
loader(8) tunable and
sysctl(8) variable
hw.syscons.sc_no_suspend_vtswitch,
disables switching between virtual terminals (graphics <-> text)
during suspend/resume (ACPI and APM). Use this option if your system is
freezing when you are running X and trying to suspend.
The following options will remove some features from the
syscons
driver and save kernel memory.
SC_NO_CUTPASTE
- This option disables ``copy and paste'' operation in virtual
terminals.
SC_NO_FONT_LOADING
- The
syscons
driver can load software
fonts on some video cards. This option removes this feature. Note that if
you still wish to use the mouse with this option then you must also use
the SC_ALT_MOUSE_IMAGE
option.
SC_NO_HISTORY
- This option disables back-scrolling in virtual terminals.
SC_NO_SYSMOUSE
- This option removes mouse support in the
syscons
driver. The mouse daemon
moused(8) will fail if this option is
defined. This option implies the
SC_NO_CUTPASTE
option too.
Driver Flags¶
The following driver flags can be used to control the
syscons
driver. Driver flags can be set
with the
hint.sc.0.flags
tunable, either in
/boot/device.hints, or else at the loader
prompt (see
loader(8)).
- 0x0080 (VESAMODE)
- This option puts the video card in the VESA mode specified by
/boot/device.hints variable
vesa_mode during kernel initialization.
Note that in order for this flag to work, the kernel must be compiled with
the
SC_PIXEL_MODE
option explained
above. A list of the available mode can be obtained via
vidcontrol(1).
- 0x0100 (AUTODETECT_KBD)
- This option instructs the syscons driver to periodically scan for a
keyboard device if it is not currently attached to one. Otherwise, the
driver only probes for a keyboard once during bootup.
Loader Tunables¶
These settings can be entered at the
loader(8)
prompt or in
loader.conf(5).
- kern.vty
- When both
syscons
and
vt(4) have been compiled into the kernel, the
one to use for the system console can be selected by setting this variable
to ‘sc
’ or
‘vt
’. If not set,
syscons
provides the default system
console.
FILES¶
- /dev/console
-
- /dev/consolectl
-
- /dev/ttyv?
- virtual terminals
- /etc/ttys
- terminal initialization information
- /usr/share/syscons/fonts/*
- font files
- /usr/share/syscons/keymaps/*
- key map files
- /usr/share/syscons/scrmaps/*
- screen map files
EXAMPLES¶
As the
syscons
driver requires the keyboard
driver and the video card driver, the kernel configuration file should contain
the following lines.
device atkbdc
device atkbd
device vga
device sc
device splash
You also need the following lines in
/boot/device.hints for these drivers.
hint.atkbdc.0.at="isa"
hint.atkbdc.0.port="0x060"
hint.atkbd.0.at="atkbdc"
hint.atkbd.0.irq="1"
hint.vga.0.at="isa"
hint.sc.0.at="isa"
If you do not intend to load the splash image or use the screen saver, the last
line is not necessary, and can be omitted.
Note that the keyboard controller driver
atkbdc
is required by the keyboard driver
atkbd
.
The following lines will set the default colors. The normal text will be green
on black background. The reversed text will be yellow on green background.
Note that you cannot put any white space inside the quoted string, because of
the current implementation of
config(8).
options
SC_NORM_ATTR=(FG_GREEN|BG_BLACK)
options
SC_NORM_REV_ATTR=(FG_YELLOW|BG_GREEN)
The following lines will set the default colors of the kernel message. The
kernel message will be printed bright red on black background. The reversed
message will be black on red background.
options
SC_KERNEL_CONS_ATTR=(FG_LIGHTRED|BG_BLACK)
options
SC_KERNEL_CONS_REV_ATTR=(FG_BLACK|BG_RED)
The following example adds the font files
cp850-8x16.fnt,
cp850-8x14.font and
cp850-8x8.font to the kernel.
options SC_DFLT_FONT
makeoptions
SC_DFLT_FONT=cp850
device sc
SEE ALSO¶
kbdcontrol(1),
login(1),
vidcontrol(1),
atkbd(4),
atkbdc(4),
keyboard(4),
screen(4),
splash(4),
ukbd(4),
vga(4),
vt(4),
kbdmap(5),
rc.conf(5),
ttys(5),
config(8),
getty(8),
kldload(8),
moused(8)
HISTORY¶
The
syscons
driver first appeared in
FreeBSD 1.0.
AUTHORS¶
The
syscons
driver was written by
Søren Schmidt
⟨sos@FreeBSD.org⟩. This manual page was written by
Kazutaka Yokota
⟨yokota@FreeBSD.org⟩.
CAVEATS¶
The amount of data that is possible to insert from the cut buffer is limited by
the {
MAX_INPUT
}, a system limit on the
number of bytes that may be stored in the terminal input queue - usually 1024
bytes (see
termios(4)).
BUGS¶
This manual page is incomplete and urgently needs revision.