int
uart_getchar(int offset)
{
/* If interrupts are enabled, use wtint assuming that either the
device itself will wake us, or that a clock interrupt will. */
if ((rdps() & 7) == 0) {
while (!uart_charav(offset)) {
wtint(0);
}
} else {
while (!uart_charav(offset))
continue;
}
return inb(com2Rbr + offset);
}
/* ( addr len -- actual ) */
static void
pc_serial_read(unsigned long *address)
{
char *addr;
int len;
len = POP();
addr = (char *)POP();
if (len != 1)
printk("pc_serial_read: bad len, addr %lx len %x\n", (unsigned long)addr, len);
if (uart_charav(*address)) {
*addr = (char)uart_getchar(*address);
PUSH(1);
} else {
PUSH(0);
}
}
char uart_getchar(int port)
{
while (!uart_charav(port));
return ((char) inb(RBR(port)) & 0177);
}