WSCONS(4) BSD Programmer's Manual WSCONS(4)
wscons - console access
option WSEMUL_SUN
option WSEMUL_NO_VT100
option WSEMUL_DEFAULT="xxx"
option WS_KERNEL_FG=WSCOL_XXX
option WS_KERNEL_BG=WSCOL_XXX
option WS_KERNEL_COLATTR=WSATTR_XXX
option WS_KERNEL_MONOATTR=WSATTR_XXX
option WSDISPLAY_COMPAT_PCVT
option WSDISPLAY_COMPAT_SYSCONS
option WSDISPLAY_COMPAT_USL
option WSDISPLAY_COMPAT_RAWKBD
wsdisplay* at ...
wskbd* at ... mux N
wsmouse* at ... mux N
pseudo-device wsmux [count]
The wscons driver provides support for machine-independent access to the
console.
wscons is made of a number of cooperating modules, in particular
• Hardware support for display adapters, keyboards and mice; see
wsdisplay(4), wskbd(4), and wsmouse(4).
• Input event multiplexor; see wsmux(4).
• Terminal emulation modules (see below).
• Compatibility options to support control operations and other low-
level behaviour of existing terminal drivers (see below).
wscons does not define its own set of terminal control sequences and spe-
cial keyboard codes in terms of termcap(5). Instead, a "terminal
emulation" is assigned to each virtual screen when the screen is created
(see wsconscfg(8)). Different terminal emulations can be active at the
same time on one display.
The following choices are available:
dumb This minimal terminal support is always available. No control se-
quences are supported besides the ASCII control characters. The
cursor is not addressable. Only ASCII keyboard codes will be
delivered, cursor and functions keys do not work.
sun The "sun" console emulation is available by default on sparc and
sparc64 architectures, or if
option WSEMUL_SUN was specified at kernel build time. It supports
the control sequences of SUN machine consoles and delivers its
keyboard codes for function and keypad keys (as far as present on
the actually used keyboard).
ANSI colors are also supported on this emulation, if the TERM en-
vironment variable is set to rcons-color.
This emulation is sufficient for full-screen applications.
vt100 is available by default, but can be disabled with
option WSEMUL_NO_VT100. It provides the most commonly used func-
tions of DEC VT100 terminals with some extensions introduced by
the DEC VT220 and DEC VT320 models. The features of the original
VT100 which are not, or not completely, implemented are:
• VT52 support, 132-column-mode, smooth scroll, light back-
ground, keyboard autorepeat control, external printer support,
keyboard locking, newline/linefeed switching: Escape sequences
related to these features are ignored or answered with stan-
dard replies. (DECANM, DECCOLM, DECSCLM, DECSCNM, DECARM,
DECPFF, DECPEX, KAM, LNM)
• Function keys are not reprogrammable and fonts can not be
downloaded. DECUDK and DECDLD sequences will be ignored.
• Neither C1 control set characters will be recognized nor will
8-bit keyboard codes be delivered.
• The "DEC supplemental graphic" font is approximated by the
ISO-latin-1 font, though there are subtle differences.
• The actual rendering quality depends on the underlying graph-
ics hardware driver. Characters might be missing in the avail-
able fonts and be substituted by more or less fitting replace-
ments.
Depending on the keyboard used, not all function keys might be
available.
In addition to the plain VT100 functions, the following features
are supported:
• ANSI colors
• Some VT220 -like presentation state settings and -reports
(DECRSPS), especially tabulator settings.
In most applications, wscons will work sufficiently as a VT220
emulator.
The WSEMUL_DEFAULT kernel option allows selecting one of the described
terminal options as the default choice. The default goes into effect at
kernel startup, i.e., for the operating system console or additional
screens allocated through the WSDISPLAY_DEFAULTSCREENS option (see
wsdisplay(4)), or if no emulation type was passed to the wsconscfg(8)
utility.
Compatibility options: these options allow running X servers or other
programs using low-level console driver functions which were written
specifically for other console drivers to run on OpenBSD systems. The op-
tions are in particular:
WSDISPLAY_COMPAT_USL Support the protocol for switches between mul-
tiple virtual screens on one display as used
by most PC-UNIX variants.
WSDISPLAY_COMPAT_RAWKBD Allows getting raw XT keyboard scancodes from
PC keyboards as needed by i386 X servers.
WSDISPLAY_COMPAT_PCVT Emulates enough of the OpenBSD / i386 "pcvt"
driver to make X servers work.
WSDISPLAY_COMPAT_SYSCONS Emulates enough of the i386 FreeBSD "syscons"
driver to make X servers work. Useful with
FreeBSD binary emulation.
Linux/i386 X servers do usually run if the first two options are enabled
together with the OpenBSD Linux binary emulation.
(To have programs looking for device special files of other console
drivers find the wscons driver entry points, symlinks are a helpful meas-
ure.)
Other options:
option WS_KERNEL_FG=WSCOL_XXX
option WS_KERNEL_BG=WSCOL_XXX
option WS_KERNEL_COLATTR="(WSATTR_XXX | WSATTR_YYY)"
option WS_KERNEL_MONOATTR="(WSATTR_XXX | WSATTR_YYY)"
Make console output originating from the kernel appear differently
than output from user level programs (via /dev/console or the
specific tty device like /dev/ttyC0). "WS_KERNEL_FG" and
"WS_KERNEL_BG" set the foreground / background used on color
displays.
The "WSCOL_XXX" arguments are colors as defined in
/usr/include/dev/wscons/wsdisplayvar.h. "WS_KERNEL_COLATTR" and
"WS_KERNEL_MONOATTR" are additional attribute flags used on color or
monochrome displays, respectively. The arguments are defined in the
same header file. Whether the attributes are supported or not
depends on the actually used graphics adapter. These options are ig-
nored by the "dumb" terminal emulation.
option WSCOMPAT_USL_SYNCTIMEOUT=nnn
The virtual screen switching protocol enabled by
"WSDISPLAY_COMPAT_USL" uses a somewhat complex handshake protocol to
pass control to user programs as X servers controlling a virtual
screen. To avoid a non-responsive application locking the whole con-
sole system, a screen switch will be rolled back if the user appli-
cation does not respond to a screen switch request within some time.
This option sets the timeout (in seconds); the default value is 5
seconds.
intro(4), wsdisplay(4), wskbd(4), wsmouse(4), wsmux(4), wsconscfg(8),
wsconsctl(8), wsfontload(8), wsmoused(8)
MirBSD #10-current December 24, 2009 2