KBDPUTC(10.2) KBDPUTC(10.2)
NAME
kbdputc, kbdrepeat, kbdclock, kbdq - keyboard interface to cons(3)SYNOPSIS
#include "keyboard.h"
void kbdputc(Queue *q, int c)
void kbdrepeat(int on)
void kbdclock(void)
extern Queue *kbdq;
DESCRIPTION
This is the internal interface between /dev/keyboard of cons(3) and the
architecture-dependent keyboard driver. Before calling any of these
functions, the global variable kbdq must be initialised; cons(3) does
not initialise it. This is usually done during system initialisation
by the keyboard driver's kbdinit function , as follows:
kbdq = qopen(4*1024, 0, 0, 0);
qnoblock(kbdq, 1);
Kbdputc puts a 16-bit Unicode character c (ie, a `rune') on the given
q, as a sequence of bytes in UTF-8 encoding (see utf(6)). If c is the
special value Latin (defined by keyboard.h), kbdputc starts collecting
characters, looking for the typeable representations of Unicode charac‐
ters defined by keyboard(6); at the end of a complete such sequence,
kbdputc queues the UTF-8 encoding of the corresponding Unicode charac‐
ter. It is up to the keyboard driver to map a suitable physical key‐
board character (or combination of characters) to the code Latin.
Drivers that need to implement repeat of keypresses in software should
call
addclock0link(kbdclock);
at the end of kbdinit, to cause kbdclock to be called each clock tick.
Kbdrepeat can then be called to enable (on is non-zero) or disable it
(on is zero). When repeat is on, kbdclock (when called) will periodi‐
cally call kbdputc(kbdq,c) where c is the last rune given to kbdputc.
The driver is responsible for enabling and disabling repeat appropri‐
ately; for instance, function keys and certainly Latin should typically
not be repeated.
SOURCE
/os/*/kbd*.c
SEE ALSOcons(3), utf(6), qio(10.2)
KBDPUTC(10.2)