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 characters
defined by keyboard(6); at the end of a complete such
sequence, kbdputc queues the UTF-8 encoding of the corre-
sponding Unicode character. It is up to the keyboard driver
to map a suitable physical keyboard character (or combina-
tion of characters) to the code Latin.
Drivers that need to implement repeat of keypresses in soft-
ware 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 periodically call
kbdputc(kbdq,c) where c is the last rune given to kbdputc.
The driver is responsible for enabling and disabling repeat
appropriately; for instance, function keys and certainly
Latin should typically not be repeated.
KBDPUTC(10.2) KBDPUTC(10.2)
SOURCE
/os/*/kbd*.c
SEE ALSO
cons(3), utf(6), qio(10.2)