void setbit(int b)
{
  const int device = 0;
  if (!b)
    *(volatile unsigned long*)0xCC006800 |= (1<<(device + 7));
  else
    *(volatile unsigned long*)0xCC006800 &= ~(1<<(device + 7));
}

void put_uart(int b)
{
  setbit(b);
  volatile int i;
  for (i=0; i<529; ++i);
}

void serial_putc(char c)
{
  int i;
  put_uart(0);
  for (i=0; i<8; ++i)
    put_uart(c & (1 << i));
  put_uart(1);
}