int main(void) {
// register exception handlers
for (unsigned i = 0; i < 32; i++) {
exc_register(i, &fault_handler);
}
exc_register(8, &trap_handler);
exc_register(18, &intr_handler);
exc_register(19, &intr_handler);
exc_register(20, &intr_handler);
exc_register(21, &intr_handler);
// unmask interrupts
intr_unmask_all();
// clear pending flags
intr_clear_all_pending();
// enable interrupts
intr_enable();
// go to user mode
EXC_STATUS &= ~0x2;
// a that prints "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_" N times and does some self-checking
volatile unsigned starts = 0;
volatile unsigned ends = 0;
volatile unsigned sent = 0;
for (unsigned k = 0; k < N; k++) {
starts++;
for (unsigned i = 0; i < 32; i++) {
putchar('@'+i);
sent+=i;
}
putchar('\n');
ends++;
if (sent != 496*(k+1) || starts != ends) {
LEDS = 0x55;
abort();
}
}
// disabling interrupts again only works in privileged mode
/* intr_disable(); */
// call exception vector number 8
trap(8);
// trigger illegal operation fault
asm volatile(".word 0xffffffff"); // illegal operation
// trigger illegal memory access fault, never reached
(*((volatile _IODEV unsigned *)0xffffffff)) = 0;
return 0;
}
void noc_receive() {
int id = get_cpuid();
done[id] = 0;
exc_register(18,&__data_resp_handler);
//exc_register(19,&__data_resp_handler);
intr_unmask_all();
intr_enable();
//puts("Interrupt handler setup");
while(done[id] != 1){;}
intr_disable();
return;
}
