void keyboard_routine(void) {
char c = inb(0x60); /* Read from port 0x60 into c */
char press = !(c & 0x80); /* First bit indicates whether pressed or released */
if (press) {
c = char_map[c & 0x7f];
if (c != '\0')printc_xy(0, 0, c);
else printc_xy(0, 0, 'C');
cb_write(&keyboard_buffer, &c, 1);
if (remaining_characters > 0) { /* Some process is waiting */
if (cb_size(&keyboard_buffer) >= remaining_characters) /* Buffer holds enough characters */
unblock(&blocked);
else if (cb_full(&keyboard_buffer)) /* Buffer doesn't hold enough characters but is full */
unblock(&blocked);
}
else if (cb_full(&keyboard_buffer)) /* No process is waiting and buffer is full */
cb_overwrite(&keyboard_buffer, &c, 1);
}
}
/*******************************************************************************
** 函数: cb_write
** 功能: 将datptr所指向的地址中的datlen长度的数据写入到pmngr->bufptr中
** 返回: 返回实际写入的数据长度, 字节为单位
** 作者: avrbase_lei
*******/
static cb_u32 cb_write(CircleBufferMngr *pmngr, cb_u8 *datptr, cb_u32 datlen)
{
cb_u32 writelen = 0, tmplen = 0;
CB_ASSERT(NULL != pmngr);
CB_ASSERT(NULL != pmngr->bufptr);
if(cb_full(pmngr))
return 0;
CB_GLOBAL_LOCK;
tmplen = pmngr->buflen - pmngr->datalen;
writelen = tmplen > datlen ? datlen : tmplen;
if(pmngr->writepos < pmngr->readpos)
{
CB_MEMCPY(
(void*)&pmngr->bufptr[pmngr->writepos],
(void*)datptr,
writelen);
}
else
{
tmplen = pmngr->buflen - pmngr->writepos;
if(writelen <= tmplen)
{
CB_MEMCPY(
(void*)&pmngr->bufptr[pmngr->writepos],
(void*)datptr,
writelen);
}
else
{
CB_MEMCPY(
(void*)&pmngr->bufptr[pmngr->writepos],
(void*)datptr,
tmplen);
CB_MEMCPY(
(void*)pmngr->bufptr,
(void*)&datptr[tmplen],
writelen - tmplen);
}
}
pmngr->writepos = (pmngr->writepos + writelen) % pmngr->buflen;
pmngr->datalen += writelen;
CB_GLOBAL_UNLOCK;
return writelen;
}