WSKBD(4) - Device Drivers Manual

WSKBD(4) - Device Drivers Manual #

WSKBD(4) - Device Drivers Manual

NAME #

wskbd - generic keyboard support in wscons

SYNOPSIS #

wskbd* at …

DESCRIPTION #

The wskbd driver handles common tasks for keyboards within the wscons(4) framework. It is attached to the hardware specific keyboard drivers and provides their connection to “wsdisplay” devices and a character device interface.

The common keyboard support consists of:

  • Mapping from keycodes (defined by the specific keyboard driver) to keysyms (hardware independent, defined in /usr/include/dev/wscons/wsksymdef.h).

  • Handling of “compose” sequences. Characters commonly not present as separate keys on keyboards can be generated after either a special “compose” key is pressed or a “dead accent” character is used.

  • Certain translations, like turning an “ALT” modifier into an “ESC” prefix.

  • Automatic key repetition (“typematic”).

  • Parameter handling for “keyboard bells”.

  • Generation of “keyboard events” for use by X servers.

The wskbd driver provides a number of ioctl functions to control key maps and other parameters. These functions are accessible through the associated “wsdisplay” device as well. A complete list is in /usr/include/dev/wscons/wsconsio.h. The wsconsctl(8) utility allows access to key maps and other variables.

The console locator in the configuration line refers to the device’s use as input part of the operating system console. A device specification containing a positive value here will only match if the device is in use as system console. (The console device selection in early system startup is not influenced.) This way, the console device can be connected to a known wskbd device instance.

The wskbd driver traps certain key sequences intended to perform special functions. The Ctrl+Alt+Esc sequence will initiate the ddb(4) kernel debugger if the “ddb.console” sysctl(8) variable is set. When attached to a wsdisplay(4) device, Ctrl+Alt+Fx switches virtual terminals and the Shift+PgUp and Shift+PgDn combinations provide scrollback functionality if the underlying hardware driver supports it. When audio devices are supported, keys Mute, VolumeUp and VolumeDown tweak mixer settings.

FILES #

/dev/wskbd*‌

/usr/include/dev/wscons/wsksymdef.h

/usr/include/dev/wscons/wsconsio.h

SEE ALSO #

akbd(4), comkbd(4), hilkbd(4), intro(4), pckbd(4), ukbd(4), wscons(4), wsmux(4), zskbd(4), wsconsctl(8)

OpenBSD 7.5 - September 3, 2016