syscons man page on FreeBSD

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SYSCONS(4)		 BSD Kernel Interfaces Manual		    SYSCONS(4)

     syscons, sc — the console driver

     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_SYSMOUSE
     options SC_PIXEL_MODE
     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:"isa"

     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 termi‐
     nals.  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 func‐
     tion 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 sys‐
     tem 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

     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 map‐
     ping 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.

   Back Scrolling
     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 indi‐
     cated 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.

   Kernel Configuration Options
     The following kernel configuration options control the syscons driver.

	    This option sets the number of virtual terminals to N.  The
	    default value is 16.

	    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.

	    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.

	    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.

	    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 combina‐
	    tion.  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.

	    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

	    Sets the size of back scroll buffer to N lines.  The default value
	    is 100.

	    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 sys‐
	    tems.  This option specifies the first character code to C to be
	    used for this purpose.  The default value is 0xd0.	A good candi‐
	    date is 0x03.

	    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.

	    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.




	    These options will set the default colors.	Available colors are
	    defined in <machine/pc/display.h>.	See EXAMPLES below.

	    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.	With‐
	    out 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.

	    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.

	    This option disables ``copy and paste'' operation in virtual ter‐

	    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.

	    This option disables back-scrolling in virtual terminals.

	    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.
     They can be set 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
	    higher 16 bits of the flags 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.  Other‐
	    wise, the driver only probes for a keyboard once during bootup.

     /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

     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 driv‐

     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 key‐
     board 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).


     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.


     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

     The amount of data that is possible to insert from the cut buffer is lim‐
     ited 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

     kbdcontrol(1), login(1), vidcontrol(1), atkbd(4), atkbdc(4), keyboard(4),
     screen(4), splash(4), ukbd(4), vga(4), kbdmap(5), rc.conf(5), ttys(5),
     config(8), getty(8), kldload(8), moused(8)

     The syscons driver first appeared in FreeBSD 1.0.

     The syscons driver was written by Søren Schmidt ⟨⟩.	 This
     manual page was written by Kazutaka Yokota ⟨⟩.

     This manual page is incomplete and urgently needs revision.

BSD			      September 10, 2009			   BSD

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