/*! Sends BYTE to the serial port. */
void serial_putc(uint8_t byte) {
enum intr_level old_level = intr_disable();
if (mode != QUEUE) {
/* If we're not set up for interrupt-driven I/O yet,
use dumb polling to transmit a byte. */
if (mode == UNINIT)
init_poll();
putc_poll(byte);
}
else {
/* Otherwise, queue a byte and update the interrupt enable register. */
if (old_level == INTR_OFF && intq_full(&txq)) {
/* Interrupts are off and the transmit queue is full.
If we wanted to wait for the queue to empty,
we'd have to reenable interrupts.
That's impolite, so we'll send a character via
polling instead. */
putc_poll(intq_getc (&txq));
}
intq_putc(&txq, byte);
write_ier();
}
intr_set_level(old_level);
}
/* Flushes anything in the serial buffer out the port in polling
mode. */
void
serial_flush(void)
{
unsigned old_level = int_intr_disable();
while (!cyb_isempty(txq))
putc_poll(cyb_getc(txq));
int_intr_setlevel(old_level);
}
/* Sends BYTE to the serial port. */
void
serial_putc(unsigned char byte)
{
unsigned old_level = int_intr_disable();
if (mode != QUEUE)
{
/* If we're not set up for interrupt-driven I/O yet,
use dumb polling to transmit a byte. */
if (mode == UNINIT)
init_poll();
putc_poll(byte);
}
else
{
/* Otherwise, queue a byte and update the interrupt enable
register. */
if (old_level == 0 && cyb_isfull(txq))
{
/* Interrupts are off and the transmit queue is full.
If we wanted to wait for the queue to empty,
we'd have to reenable interrupts.
That's impolite, so we'll send a character via
polling instead. */
putc_poll(cyb_getc(txq));
}
if (byte == '\n')
{
cyb_putc(txq, '\r');
}
cyb_putc(txq, byte);
write_ier();
}
int_intr_setlevel(old_level);
}
/*! Flushes anything in the serial buffer out the port in polling mode. */
void serial_flush(void) {
enum intr_level old_level = intr_disable();
while (!intq_empty(&txq))
putc_poll(intq_getc(&txq));
intr_set_level(old_level);
}
