static WORKING_AREA(display_wa, 128);
static msg_t display(void *arg) {
  msg_t message;
  char clock[16+1];
  (void) arg;
  if (RDY_OK == chMBFetch(&mb_display, &message, TIME_INFINITE)) {
    rtcGetTimeTm(&RTCD1, &TM);
    xsprintf(clock, "%02d%02d%02d", TM.tm_hour, TM.tm_min, TM.tm_sec);
    ws0010_string(clock, LINE1, 10);
  }
  return 0;
}


static void rtc_cb(RTCDriver *rtcp, rtcevent_t event) {
  (void)rtcp;
  switch (event) {
  case RTC_EVENT_OVERFLOW:
    break;
  case RTC_EVENT_SECOND:
    chMBPost(&mb_display, (msg_t) NULL, TIME_IMMEDIATE);
    break;
  case RTC_EVENT_ALARM:
    break;
  }
}