NIOS II With uCOSII

1、如果使用uCOS，那么Qsys中Nios II核就不能使用外部中断控制器（EIC）。

2、遇到很迷惑的问题，运行uCOSII的实例代码，总是在第二个OSTimeDlyHMSM(0, 0, 3, 0);出错。

单步调试后，发现代码在执行到NIOS2_WRITE_STATUS (status);汇编代码为ldw r2,-8(fp)时出错，暂停程序运行后，程序指向00000000：Call 0x0处。

void task1(void* pdata)
{
  while (1)
  {
    printf("Hello from task1\n");
    OSTimeDlyHMSM(0, 0, 3, 0);
  }
}
/* Prints "Hello World" and sleeps for three seconds */
void task2(void* pdata)
{
  while (1)
  {
    printf("Hello from task2\n");
    OSTimeDlyHMSM(0, 0, 3, 0);
  }
}
/* The main function creates two task and starts multi-tasking */
int main(void)
{
  OSTaskCreateExt(task1,
                  NULL,
                  (void *)&task1_stk[TASK_STACKSIZE-1],
                  TASK1_PRIORITY,
                  TASK1_PRIORITY,
                  task1_stk,
                  TASK_STACKSIZE,
                  NULL,
                  0);
  OSTaskCreateExt(task2,
                  NULL,
                  (void *)&task2_stk[TASK_STACKSIZE-1],
                  TASK2_PRIORITY,
                  TASK2_PRIORITY,
                  task2_stk,
                  TASK_STACKSIZE,
                  NULL,
                  0);
  OSStart();
  return 0;
}