freebsd-skq/share/man/man4/syscons.4

.\"
.\" Copyright (c) 1999
.\" Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
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.Dd June 30, 1999
.Dt SYSCONS 4
.Os FreeBSD
.Sh NAME
.Nm syscons ,
.Nm sc
.Nd
the console driver
.Sh SYNOPSIS
.Cd "options MAXCONS=N"
.Cd "options SC_ALT_MOUSE_IMAGE"
.Cd "options SC_DISABLE_DDBKEY"
.Cd "options SC_DISABLE_REBOOT"
.Cd "options SC_HISTORY_SIZE=N"
.Cd "options SC_MOUSE_CHAR=C"
.Cd "options SC_NO_CUTPASTE"
.Cd "options SC_NO_FONT_LOADING"
.Cd "options SC_NO_HISTORY"
.Cd "options SC_NO_PALETTE_LOADING"
.Cd "options SC_NO_SYSMOUSE"
.Cd "options SC_PIXEL_MODE"
.Cd "options SC_TWOBUTTON_MOUSE
.Cd "options SC_NORM_ATTR=_attribute_"
.Cd "options SC_NORM_REV_ATTR=_attribute_"
.Cd "options SC_KERNEL_CONS_ATTR=_attribute_"
.Cd "options SC_KERNEL_CONS_REV_ATTR=_attribute_"
.Cd "options SC_DFLT_FONT"
.Cd "makeoptions SC_DFLT_FONT=_font_name_"
.Cd "device sc0 at isa?" Op flags Ar flags
.Sh DESCRIPTION
The
.Nm
driver provides multiple virtual terminals.
It resembles the SCO color console driver.
.Pp
The
.Nm
driver is implemented on top of the keyboard driver
.Pq Xr atkbd 4
and the video card driver
.Pq Xr vga 4
and so requires both of them to be configured in the system.
.Pp
There can be only one 
.Nm
device defined in the system.
.Ss Virtual Terminals
The
.Nm
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.
.Pp
In order to use virtual terminals, they must be individually
marked ``on'' in
.Pa /etc/ttys
so that 
.Xr getty 8
will recognize them to be active and run
.Xr login 1 
to let the user to login to the system.
By default, only the first eight virtual terminals are activated in
.Pa /etc/ttys .
.Pp
You press the
.Em 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.
.Bd -literal -offset indent
Alt-F1   ttyv0      Alt-F7   ttyv6      Shift-Alt-F1   ttyv10
Alt-F2   ttyv1      Alt-F8   ttyv7      Shift-Alt-F2   ttyv11
Alt-F3   ttyv2      Alt-F9   ttyv8      Shift-Alt-F3   ttyv12
Alt-F4   ttyv3      Alt-F10  ttyv9      Shift-Alt-F4   ttyv13
Alt-F5   ttyv4      Alt-F11  ttyv10     Shift-Alt-F5   ttyv14
Alt-F6   ttyv5      Alt-F12  ttyv11     Shift-Alt-F6   ttyv15
.Ed
.Pp
You can also use the ``nscr'' key (usually the
.Em PrintScreen
key on the AT Enhanced keyboard) to cycle available virtual terminals.
.Pp
The default number of available virtual terminals is 16.
This can be changed by the kernel configuration option
.Em MAXCONS
(see below).
.Pp
Note that the X server usually requires a virtual terminal for display
purposes, so at least one terminal must be left unused by 
.Xr getty 8
so that it can be used by the X server.
.Ss Key Definitions and Function Key Strings
The
.Nm
driver, in conjunction with the keyboard driver, allows the user
to change key definitions and function key strings.
The
.Xr 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
.Xr keyboard 4
and
.Xr kbdmap 5
for the keymap file.
.Pp
You may want to set the
.Ar keymap
variable in 
.Pa /etc/rc.conf.local
to the desired keymap file so that it will be automatically loaded
when the system starts up.
.Ss Software Font
For most modern video cards, e.g. VGA, the
.Nm
driver and the video card driver allow the user to change 
the font used on the screen.
The
.Xr vidcontrol 1
command can be used to load a font file from 
.Pa /usr/share/syscons/fonts .
.Pp
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 size of font.
It is better to always load these three sizes of the same font.
.Pp
You may set
.Ar font8x8 ,
.Ar font8x14 
and
.Ar font8x16
variables in
.Pa /etc/rc.conf.local
to the desired font files so that they will be automatically loaded
when the system starts up.
.Pp
Optionally you can make a particular font file as the default font.
See the
.Em SC_DFLT_FONT
option below.
.Ss Screen Map
If your video card does not support software font, you may still be able
to have similar effect by re-mapping font hard-wired in the video card.
Use
.Xr vidcontrol 1
to load a screen map file which defines mapping between character codes.
.Ss Mouse Support and Copy-and-Paste
You can use your mouse to copy text on the screen and paste it as if
it is typed by hand.
You must be running the mouse daemon
.Xr moused 8
and enable the mouse cursor in the virtual terminal via
.Xr vidcontrol 1 .
.Pp
Pressing the mouse button 1 (usually the left button) will start selection.
Releasing the button 1 will end the selection process.
The selected text will be marked by inverting foreground and 
background colors.
You can press the 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 your pressing the button 2 (usually the
middle button) as many times as you like.
.Pp
If your mouse has only two buttons, you may want to use the
.Em SC_TWOBUTTON_MOUSE
option below to make the right button to paste the text.
Alternatively you can make the mouse daemon
to emulate the middle button.
See the man page for
.Xr moused 8
for more details.
.Ss Back Scrolling
The
.Nm
driver allows the user to browse the output which has ``scrolled off''
from the top of the screen.
.Pp
Press the ``slock'' key (usually 
.Em ScrllLock 
and/or 
.Em Pause 
keys on many AT Enhanced keyboards) and the terminal is 
in the ``back scrolling'' mode.
It is indicated by the 
.Em Scroll Lock
LED.
Use arrow keys, 
.Em Page Up/Down 
keys and 
.Em Home/End 
keys to scroll buffered terminal output.
Press the ``slock'' key again to get back to the normal terminal mode.
.Pp
The size of the back-scroll buffer can be set by the
.Em SC_HISTORY_SIZE
option below.
.Ss Screen Saver
The
.Nm
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 mouse.
See
.Xr splash 4
and
.Xr vidcontrol 1
for more details.
.Sh DRIVER CONFIGURATION
.Ss Kernel Configuration Options
The following kernel configuration options control the
.Nm
driver.
.Bl -tag -width MOUSE
.It Em MAXCONS=N
This option sets the number of virtual terminals to
.Fa N .
The default value is 16.
.It Em SC_ALT_MOUSE_IMAGE
This option selects the alternative way of displaying the mouse cursor
in the virtual terminal.
It may be vastly costly 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.
.It Em SC_DISABLE_DDBKEY
This option disables the ``debug'' key (by default, it is 
.Em Alt-Esc ,
or
.Em Ctl-PrintScreen
).
It will prevent the user from
entering the kernel debugger DDB by pressing the key combination.  
DDB will still be invoked when the kernel panics or hits a break point 
if it is included in the kernel.
.It Em SC_DISABLE_REBOOT
This option disables the ``reboot'' key (by default, it is 
.Em Ctl-Alt-Del
), so that the casual user may not accidentally reboot the system.
.It Em SC_HISTORY_SIZE=N
Sets the size of back scroll buffer to 
.Fa N
lines.
The default value is 100.
.It Em SC_MOUSE_CHAR=C
Unless the
.Em SC_ALT_MOUSE_IMAGE
option above is specified, the
The
.Nm
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
.Fa C
to be used for this purpose.
The default value is 0xd0.
A good candidate is 0x03.
.It Em 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 the this option is NOT defined, you can reduce the kernel size a lot.
See the
.Em VESA800X600
flag below.
.It Em 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
.Sx Mouse Support and Copy-and-Paste
above.
.It Em SC_NORM_ATTR=_attribute_
.It Em SC_NORM_REV_ATTR=_attribute_
.It Em SC_KERNEL_CONS_ATTR=_attribute_
.It Em SC_KERNEL_CONS_REV_ATTR=_attribute_
These options will set the default colors.
Available colors are defined in
.Pa /usr/include/machine/pc/display.h .
See
.Sx EXAMPLE
below.
.It Em SC_DFLT_FONT
This option will specify the default font.
Available fonts are: iso, iso2, koi8-r, cp437, cp850, cp865 and cp866.
16-line, 14-line and 8-line font data will be compiled in.  
Without this option, the
.Nm
driver will use whatever font already loaded in the video card,
unless you explicitly load software font at startup.
See
.Sx EXAMPLE
below.
.El
.Pp
The following options will remove some features from the
.Nm
driver and save kernel memory.
.Bl -tag -width MOUSE
.It Em SC_NO_CUTPASTE
This option disables ``copy and paste'' operation in virtual
terminals.
.It Em SC_NO_FONT_LOADING
The
.Nm
driver can load software font on some video cards.
This option removes this feature.
.It Em SC_NO_HISTORY
This option disables back-scrolling in virtual terminals.
.\".It Em SC_NO_PALETTE_LOADING
.It Em SC_NO_SYSMOUSE
This option removes mouse support in the
.Nm
driver.
The mouse daemon
.Xr moused 8
will fail if this option is defined.
This option implies the
.Em SC_NO_CUTPASTE
option too.
.El
.Ss Driver Flags
The following driver flags can be used to control the
.Nm
driver.
They can be set either in the kernel configuration file
.Pq see Xr config 8 ,
or else in the User Configuration Menu at boot
time
.Pq see Xr boot 8 .
.Bl -tag -width bit_0
.\".It bit 0 (VISUAL_BELL)
.\"Uses the ``visual'' bell.
.\"The screen will blink instead of generating audible sound.
.\".It bit 1,2 (CURSOR_TYPE)
.\"This option specifies the cursor appearance.
.\"Possible values are:
.\".Bl -tag -width TYPE -compact
.\".It Em 0
.\"normal block cursor
.\".It Em 2
.\"blinking block cursor
.\".It Em 4
.\"underline cursor
.\".It Em 6
.\"blinking underline (aka destructive) cursor
.\".El
.\".It bit 6 (QUIET_BELL)
.\"This option suppresses the bell, whether audible or visual, 
.\"if it is rung in a background virtual terminal.
.It 0x0080 (VESA800X600)
This option puts the video card in the VESA 800x600 dots, 16 color
mode.
It may be useful for laptop computers for which the 800x600 mode
is otherwise unsupported by the X server.
Note that in order for this flag to work, the kernel must be 
compiled with the
.Em SC_PIXEL_MODE
option explained above.
.\"Note also that the ``copy-and-paste'' function is not currently supported 
.\"in this mode and the mouse pointer will not be displayed.
.It 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.
.El
.Sh FILES
.Bl -tag -width /usr/share/syscons/xxxxyyyyzzz -compact
.It Pa /dev/console
.It Pa /dev/consolectl
.It Pa /dev/ttyv?
virtual terminals
.It Pa /etc/ttys
terminal initialization information
.It Pa /usr/share/syscons/fonts/*
font files
.It Pa /usr/share/syscons/keymaps/*
key map files
.It Pa /usr/share/syscons/scrmaps/*
screen map files
.El
.Sh EXAMPLE
As the 
.Nm
driver requires the keyboard driver and the video card driver,
the kernel configuration file should contain the following lines.
.Pp
.Bd -literal -offset indent
device atkbdc0 at isa? port IO_KBD
device atkbd0 at atkbdc? irq 1
device vga0 at isa? conflicts
device sc0 at isa?

pseudo-device splash
.Ed
.Pp
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.
.Pp
Note that the keyboard controller driver
.Nm atkbdc
is required by the keyboard driver
.Nm atkbd .
.Pp
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
.Xr config 8 .
.Pp
.Dl "options SC_NORM_ATTR=(FG_GREEN|BG_BLACK)
.Dl "options SC_NORM_REV_ATTR=(FG_YELLOW|BG_GREEN)
.Pp
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.
.Pp
.Dl "options SC_KERNEL_CONS_ATTR=(FG_LIGHTRED|BG_BLACK)
.Dl "options SC_KERNEL_CONS_REV_ATTR=(FG_BLACK|BG_RED)
.Pp
The following example adds the font files
.Pa cp850-8x16.fnt ,
.Pa cp850-8x14.font 
and
.Pa cp850-8x8.font
to the kernel.
.Pp
.Dl "options SC_DFLT_FONT"
.Dl "makeoptions SC_DFLT_FONT=cp850
.Dl "device sc0 at isa?
.Pp
.\".Sh DIAGNOSTICS
.\".Sh CAVEATS
.Sh BUGS
This manual page is incomplete and urgently needs revision.
.Sh SEE ALSO
.Xr kbdcontrol 1 ,
.Xr login 1 ,
.Xr vidcontrol 1 ,
.Xr atkbd 4 ,
.Xr atkbdc 4 ,
.Xr keyboard 4 ,
.Xr screen 4 ,
.Xr splash 4 ,
.Xr ukbd 4 ,
.Xr vga 4 ,
.Xr kbdmap 5 ,
.Xr rc.conf 5 ,
.Xr screenmap 5 ,
.Xr ttys 5 ,
.Xr config 8 ,
.Xr getty 8 ,
.Xr kldload 8 ,
.Xr moused 8 .
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 1.0 .
.Sh AUTHORS
The
.Nm
driver was written by
.An S<EFBFBD>ren Schmidt Aq sos@FreeBSD.org .
This manual page was written by
.An Kazutaka Yokota Aq yokota@FreeBSD.org .