RT-Thread-在rtt-console和shell中使用JLINK RTT来代替串口调试设备RT-Thread问答社区

在rtt-console和shell中使用JLINK RTT来代替串口调试设备

发布于 2018-05-21 14:27:39 浏览：13360 订阅该版

[ 本帖最后由 FlyLu 于 2018-6-27 15:39 编辑 ]<br><br>* 本帖最后由 FlyLu 于 2018-5-21 14:27 编辑 *

rtt-shell是一个非常好用的组件，但通常会以串口作为shell的设备

如果硬件设备串口有限，可以通过使用JLINK RTT功能，也可以做到mcu与pc的交互。并且可以作为console和shell的设备

关于更多JLINK RTT
[https://www.segger.com/products/debug-probes/j-link/technology/about-real-time-transfer/](https://www.segger.com/products/debug-probes/j-link/technology/about-real-time-transfer/)

```/*============================ INCLUDES ======================================*/
#include <rthw.h>
#include "SEGGER_RTT.h"

/*============================ MACROS ========================================*/
#define SEGGER_RTT_THREAD_STACKSIZE         512
#define SEGGER_RTT_THREAD_PRIOR             19

#define SERRER_RTT_THREAD_DELAY             30
    
/*============================ MACROFIED FUNCTIONS ===========================*/
/*============================ TYPES =========================================*/
struct segger_rtt_device
{
    struct rt_device          parent;
};

/*============================ GLOBAL VARIABLES ==============================*/
/*============================ LOCAL VARIABLES ===============================*/
static struct segger_rtt_device  sSeggerRtt;

/*============================ PROTOTYPES ====================================*/
/*============================ IMPLEMENTATION ================================*/

static rt_size_t rt_segger_rtt_read(struct rt_device *dev,
                                    rt_off_t          pos,
                                    void             *buffer,
                                    rt_size_t         size)
{
    return SEGGER_RTT_Read(0, buffer, size);

}

static rt_size_t rt_segger_rtt_write(struct rt_device *dev,
                                     rt_off_t          pos,
                                     const void       *buffer,
                                     rt_size_t         size)
{
    return SEGGER_RTT_Write(0, buffer, size);
}

static rt_err_t rt_segger_rtt_open(struct rt_device *dev, rt_uint16_t oflag)
{
    return RT_EOK;
}

static rt_err_t rt_segger_rtt_close(struct rt_device *dev)
{
    return RT_EOK;
}

static rt_err_t rt_segger_rtt_init(struct rt_device *dev)
{
    return RT_EOK;
}

static rt_err_t rt_segger_rtt_control(struct rt_device *dev,
                                      rt_uint8_t        cmd,
                                      void             *args)
{
    return RT_EOK;
}

rt_err_t rt_hw_segger_rtt_register(struct segger_rtt_device  *segger_rtt,
                                   const char                *name,
                                   rt_uint32_t                flag,
                                   void                      *data)
{
    struct rt_device *device;
    RT_ASSERT(segger_rtt != RT_NULL);

device = &(segger_rtt->parent);

device->type        = RT_Device_Class_Char;
    device->rx_indicate = RT_NULL;
    device->tx_complete = RT_NULL;

device->init        = rt_segger_rtt_init;
    device->open        = rt_segger_rtt_open;
    device->close       = rt_segger_rtt_close;
    device->read        = rt_segger_rtt_read;
    device->write       = rt_segger_rtt_write;
    device->control     = rt_segger_rtt_control;
    device->user_data   = data;

/* register a character device */
    return rt_device_register(device, name, flag);
}

static void segger_rtt_client_thread_entry (void *parameter)
{
    struct segger_rtt_device  *segger_rtt;
    uint32_t                   count;

rt_kprintf("Hello SEGGER Real-Time-Terminal <br>");
    segger_rtt = (struct segger_rtt_device *)rt_device_find("rtdebug");
    RT_ASSERT(segger_rtt != RT_NULL);

for (;;) {
        if ((count = SEGGER_RTT_HasData(0)) != 0) {
            if (segger_rtt->parent.rx_indicate != RT_NULL) {
                segger_rtt->parent.rx_indicate(&segger_rtt->parent, count);
            }
        }
        rt_thread_delay(rt_tick_from_millisecond(SERRER_RTT_THREAD_DELAY));
    }
}

void segger_rtt_device_init(void)
{                                           
    rt_hw_segger_rtt_register(&sSeggerRtt, "rtdebug", 0, NULL);
}

ALIGN(RT_ALIGN_SIZE)
static rt_uint8_t segger_rtt_stack[SEGGER_RTT_THREAD_STACKSIZE];
static struct rt_thread segger_rtt_thread;

void segger_rtt_client_thread_init(void)
{
    int result;
    
    result = rt_thread_init(&segger_rtt_thread,
            "rtdebug", 
            segger_rtt_client_thread_entry,
            RT_NULL,
            (rt_uint8_t *)segger_rtt_stack,
            sizeof(segger_rtt_stack), 
            SEGGER_RTT_THREAD_PRIOR,
            20);

if (RT_EOK == result)
        rt_thread_startup(&segger_rtt_thread);
}

```

1. 好像该JLINK RTT没有中断，而是通过访问一块共享内存，所以建立一个查询线程，定时去检测是否有数据更新。如果存在则通知给shell
2. JLINK RTT配合j-link RTT Viewer支持多个通道打印，可以将信息输出到不同的窗口，这里只简单使用默认的通道0作为输入输出，作为rtt-console和rt-shell功能
3. rtt设备结构保留，有需求在进一步扩展，小伙伴们也可以自行修改

使用方法：

1. 下载附件，放到到你的BSP目录，并且在rtconfig.h 添加 #define RT_USING_SEGGER_RTT
2. 在rtconfig.h修改RT_CONSOLE_DEVICE_NAME的名字为 "rtdebug"（console 功能）
3. 将segger_rtt_device_init()函数放到rt_hw_board_init()中，并且需要在rt_console_set_device()前面
```void rt_hw_board_init(void)
{
    /* NVIC Configuration */
    NVIC_Configuration();

/* Configure the SysTick */
    SysTick_Config( SystemCoreClock / RT_TICK_PER_SECOND );

#if STM32_EXT_SRAM
    EXT_SRAM_Configuration();
#endif

extern void segger_rtt_device_init(void);
    segger_rtt_device_init();
    
    rt_hw_usart_init();

rt_console_set_device(RT_CONSOLE_DEVICE_NAME);

#ifdef RT_USING_COMPONENTS_INIT
    rt_components_board_init();
#endif
}```
4. 在rt_init_thread_entry线程中添加segger_rtt_client_thread_init()；
```void rt_init_thread_entry(void* parameter)
{
#ifdef RT_USING_COMPONENTS_INIT
    /* initialization RT-Thread Components */
    rt_components_init();
#endif
    
    extern void segger_rtt_client_thread_init(void);
    segger_rtt_client_thread_init();

}```
 
使用效果：

唯一不好的一点就是，这个j-link RTT Viewer（如果没找到，更新高版本的jlink驱动）输入没有向putty那样方便，并且那个table键打不出来。

![6YP`[MO$9TA{L)Q53SM{C35.png](https://oss-club.rt-thread.org/uploads/201805/21/132258wjh9u9n3is2wuw24.png)

![H]QUJOVSMU_[6XR3O4ETQOG.png](https://oss-club.rt-thread.org/uploads/201805/21/133832sz2lvw1seg0xwphv.png)

下载附件 [SEGGER_RTT.rar](https://oss-club.rt-thread.org/uploads/201805/21/140424tr4p133bttzr3bta.rar)