rtt串口中断接收函数的质疑

发布于 2018-03-30 08:31:37 浏览：4630 订阅该版

* 本帖最后由 aozima 于 2018-3-30 09:45 编辑 *

串口中断函数void rt_hw_serial_isr(struct rt_serial_device *serial, int event)

中断接收的case:
```case RT_SERIAL_EVENT_RX_IND:
        {
            int ch = -1;
            rt_base_t level;
            struct rt_serial_rx_fifo* rx_fifo;

/* interrupt mode receive */
            rx_fifo = (struct rt_serial_rx_fifo*)serial->serial_rx;
            RT_ASSERT(rx_fifo != RT_NULL);

while (1)
            {
                ch = serial->ops->getc(serial);
                if (ch == -1) break;

/* disable interrupt */
                level = rt_hw_interrupt_disable();

rx_fifo->buffer[rx_fifo->put_index] = ch;
                rx_fifo->put_index += 1;
                if (rx_fifo->put_index >= serial->config.bufsz) rx_fifo->put_index = 0;

/* if the next position is read index, discard this 'read char' */
                if (rx_fifo->put_index == rx_fifo->get_index)
                {
                    rx_fifo->get_index += 1;
                    if (rx_fifo->get_index >= serial->config.bufsz) rx_fifo->get_index = 0;
                }

/* enable interrupt */
                rt_hw_interrupt_enable(level);
            }

/* invoke callback */
            if (serial->parent.rx_indicate != RT_NULL)
            {
                rt_size_t rx_length;

/* get rx length */
                level = rt_hw_interrupt_disable();
                rx_length = (rx_fifo->put_index >= rx_fifo->get_index)? (rx_fifo->put_index - rx_fifo->get_index):
                    (serial->config.bufsz - (rx_fifo->get_index - rx_fifo->put_index));
                rt_hw_interrupt_enable(level);

serial->parent.rx_indicate(&serial->parent, rx_length);
            }
            break;
        }```

从中可以看出他是先保存到缓存里面的,但是问题来了,serial->serial_rx 这个指针一直都是NULL,这一点在调试单步运行设置断点的时候可以看出.既然都是指针,又没有指向一个确切的地址,为何可以保存数据,百思不得姐!!!

拜请大神解惑!!! 万分感谢!!!