Zigbee学习-添加一个简单应用到OSAL中

来源：互联网发布：程序员创业知乎编辑：程序博客网时间：2024/05/16 09:45

Zstack是Zigbee协议的代码实现，本次总结我在学习TI在51内核上开发的Zstack，由于zigbee栈实现起来非常复杂而困难，因此在本Zstack中引入了操作系统-OSAL，用来协调、调度各个任务，本篇将总结SampleApp在OSAL中的初始化及任务轮训的实现机制。当系统上电后，开始执行Zmian中的main函数，如下：

int main( void ){  // Turn off interrupts  osal_int_disable( INTS_ALL ); //关闭所有中断  // Initialization for board related stuff such as LEDs  HAL_BOARD_INIT();             //初始化系统时钟  // Make sure supply voltage is high enough to run  zmain_vdd_check();            //检查芯片电压是否正常  // Initialize board I/O  InitBoard( OB_COLD );         //初始化I/O ，LED 、Timer 等  // Initialze HAL drivers  HalDriverInit();              //初始化芯片各硬件模块  // Initialize NV System  osal_nv_init( NULL );         //初始化Flash 存储器  // Initialize the MAC  ZMacInit();                   //初始化MAC 层  // Determine the extended address  zmain_ext_addr();             //确定IEEE 64位地址  // Initialize basic NV items  zgInit();                     //初始化非易失变量#ifndef NONWK  // Since the AF isn't a task, call it's initialization routine  afInit();#endif  // Initialize the operating system  <span style="color: rgb(255, 0, 0);">osal_init_system();           //初始化操作系统</span>  // Allow interrupts  osal_int_enable( INTS_ALL );  //使能全部中断  // Final board initialization  InitBoard( OB_READY );        //最终板载初始化  // Display information about this device  zmain_dev_info();             //显示设备信息  /* Display the device info on the LCD */#ifdef LCD_SUPPORTED  zmain_lcd_init();             //初始化LCD#endifosalInitTasks(); #ifdef WDT_IN_PM1  /* If WDT is used, this is a good place to enable it. */  WatchDogEnable( WDTIMX );#endif  <span style="color:#ff0000;">osal_start_system(); // No Return from here 执行操作系统，进去后不会返回</span>  return 0;  // Shouldn't get here.} // main()

其中红色标注osal_init_system()及osal_start_system()需要特别注意，其中osal_start_system()为启动操作系统（后面有介绍），而osal_init_system()为操作系统的初始化操作，其源代码如下：

uint8 osal_init_system( void ){  // Initialize the Memory Allocation System  osal_mem_init();  // Initialize the message queue  osal_qHead = NULL;  // Initialize the timers  osalTimerInit();  // Initialize the Power Management System  osal_pwrmgr_init();  // Initialize the system tasks. <span style="color:#ff0000;"> osalInitTasks(); </span>  // Setup efficient search for the first free block of heap.  osal_mem_kick();  return ( SUCCESS );}

如上，操作系统的初始化包含了内存、消息队列、电源管理、任务队列等，其中我们需要特别关注红色标注的osalInitTasks()，此函数负责初始化系统任务，我们所写SampleApp任务在此函数内被初始化，源码如下：

void osalInitTasks( void ){  uint8 taskID = 0;  // 分配内存，返回指向缓冲区的指针  tasksEvents = (uint16 *)osal_mem_alloc( sizeof( uint16 ) * tasksCnt);  // 设置所分配的内存空间单元值为0  osal_memset( tasksEvents, 0, (sizeof( uint16 ) * tasksCnt));  // 任务优先级由高向低依次排列，高优先级对应taskID 的值反而小  macTaskInit( taskID++ );  //macTaskInit(0) ，用户不需考虑  nwk_init( taskID++ );     //nwk_init(1)，用户不需考虑  Hal_Init( taskID++ );     //Hal_Init(2) ，用户需考虑#if defined( MT_TASK )  MT_TaskInit( taskID++ );#endif  APS_Init( taskID++ );      //APS_Init(3) ，用户不需考虑#if defined ( ZIGBEE_FRAGMENTATION )  APSF_Init( taskID++ );#endif  ZDApp_Init( taskID++ );    //ZDApp_Init(4) ，用户需考虑#if defined ( ZIGBEE_FREQ_AGILITY ) || defined ( ZIGBEE_PANID_CONFLICT )  ZDNwkMgr_Init( taskID++ );#endif  //用户创建的任务  <span style="color:#ff0000;">SampleApp_Init( taskID ); </span> // SampleApp_Init _Init(5) ，用户需考虑}

红色标注部分是我们必须要写的，其中taskID为任务编号，升序排列，越大优先级越低，当初始化完任务后，操作系统启动后会不停查询任务事件，并根据taskID进行基于优先级的区别处理，在本次应用中其代码如下：

void SampleApp_Init( uint8 task_id ){   SampleApp_TaskID = task_id;   //osal分配的任务ID随着用户添加任务的增多而改变  SampleApp_NwkState = DEV_INIT;//设备状态设定为ZDO层中定义的初始化状态  SampleApp_TransID = 0;        //消息发送ID（多消息时有顺序之分）    // Device hardware initialization can be added here or in main() (Zmain.c).  // If the hardware is application specific - add it here.  // If the hardware is other parts of the device add it in main(). #if defined ( BUILD_ALL_DEVICES )  // The "Demo" target is setup to have BUILD_ALL_DEVICES and HOLD_AUTO_START  // We are looking at a jumper (defined in SampleAppHw.c) to be jumpered  // together - if they are - we will start up a coordinator. Otherwise,  // the device will start as a router.  if ( readCoordinatorJumper() )    zgDeviceLogicalType = ZG_DEVICETYPE_COORDINATOR;  else    zgDeviceLogicalType = ZG_DEVICETYPE_ROUTER;#endif // BUILD_ALL_DEVICES//该段的意思是，如果设置了HOLD_AUTO_START宏定义，将会在启动芯片的时候会暂停启动//流程，只有外部触发以后才会启动芯片。其实就是需要一个按钮触发它的启动流程。  #if defined ( HOLD_AUTO_START )  // HOLD_AUTO_START is a compile option that will surpress ZDApp  //  from starting the device and wait for the application to  //  start the device.  ZDOInitDevice(0);#endif  // Setup for the periodic message's destination address 设置发送数据的方式和目的地址寻址模式  // Broadcast to everyone 发送模式:广播发送  SampleApp_Periodic_DstAddr.addrMode = (afAddrMode_t)AddrBroadcast;//广播  SampleApp_Periodic_DstAddr.endPoint = SAMPLEAPP_ENDPOINT; //指定端点号:20  SampleApp_Periodic_DstAddr.addr.shortAddr = 0xFFFF;//指定目的网络地址为广播地址  // Setup for the flash command's destination address - Group 1 组播发送  SampleApp_Flash_DstAddr.addrMode = (afAddrMode_t)afAddrGroup; //组寻址  SampleApp_Flash_DstAddr.endPoint = SAMPLEAPP_ENDPOINT; //指定端点号:20,1~240  SampleApp_Flash_DstAddr.addr.shortAddr = SAMPLEAPP_FLASH_GROUP;//组号0x0001  // Fill out the endpoint description. 定义本设备用来通信的APS层端点描述符  SampleApp_epDesc.endPoint = SAMPLEAPP_ENDPOINT; //指定端点号:20  SampleApp_epDesc.task_id = &SampleApp_TaskID;   //SampleApp 描述符的任务ID  SampleApp_epDesc.simpleDesc            = (SimpleDescriptionFormat_t *)&SampleApp_SimpleDesc;//SampleApp简单描述符  SampleApp_epDesc.latencyReq = noLatencyReqs;    //延时策略<span style="color:#ff0000;">  // Register the endpoint description with the AF  afRegister( &SampleApp_epDesc );    //向AF层登记描述符  // Register for all key events - This app will handle all key events  RegisterForKeys( SampleApp_TaskID ); // 登记所有的按键事件</span>  // By default, all devices start out in Group 1  SampleApp_Group.ID = 0x0001;//组号  osal_memcpy( SampleApp_Group.name, "Group 1", 7  );//设定组名  aps_AddGroup( SAMPLEAPP_ENDPOINT, &SampleApp_Group );//把该组登记添加到APS中#if defined ( LCD_SUPPORTED )  HalLcdWriteString( "SampleApp", HAL_LCD_LINE_1 ); //如果支持LCD，显示提示信息#endif}

如上，红色标注部分依然是我们需要特别注意的，afRegister( &SampleApp_epDesc )该函数将endpoint注册至AF（即Aapplication Frame）层，该层负责管理端点进行数据传输；而RegisterForKeys( SampleApp_TaskID )是将所有的按键事件注册绑定到我们SampleApp中，注册后当有按键事件发生时，可以在系统的任务轮询中进入SampleApp的时间相应函数中，在本应用中该函数为SampleApp_ProcessEvent( uint8 task_id, uint16 events )；

操作系统的启动由osal_start_system()函数负责，该函数为整个上电启动过程最后的操作，进入该函数后会不停查询处理任务事件，该函数原型如下：

void osal_start_system( void ){#if !defined ( ZBIT ) && !defined ( UBIT )  for(;;)  // Forever Loop#endif  {    uint8 idx = 0;    osalTimeUpdate();   //扫描哪个事件被触发了，然后置相应的标志位    Hal_ProcessPoll();  //轮询TIMER与UART This replaces MT_SerialPoll() and osal_check_timer().        do {      if (tasksEvents[idx])  // Task is highest priority that is ready.      {        break;               //得到待处理的最高优先级任务索引号 idx      }    } while (++idx < tasksCnt);    if (idx < tasksCnt)    {      uint16 events;      halIntState_t intState;      HAL_ENTER_CRITICAL_SECTION(intState);// 进入临界区,保护      events = tasksEvents[idx];           //提取需要处理的任务中的事件      tasksEvents[idx] = 0;                //清除本次任务的事件      HAL_EXIT_CRITICAL_SECTION(intState); // 退出临界区     <span style="color:#ff0000;"> events = (tasksArr[idx])( idx, events )</span>;//通过指针调用任务处理函数，关键，其中sampleAPP的处理函数即从此处调用      HAL_ENTER_CRITICAL_SECTION(intState);   //进入临界区      tasksEvents[idx] |= events;  // 保存未处理的事件 Add back unprocessed events to the current task.      HAL_EXIT_CRITICAL_SECTION(intState);    // 退出临界区    }#if defined( POWER_SAVING )    else  // Complete pass through all task events with no activity?    {      osal_pwrmgr_powerconserve();  // Put the processor/system into sleep    }#endif  }}

如上，该函数为不断轮训任务时间，并根据任务ID进行处理（红色标注部分），跟踪tasksArr[idx]发现其被赋值如下：

const pTaskEventHandlerFn tasksArr[] = {  macEventLoop,  nwk_event_loop,  Hal_ProcessEvent,#if defined( MT_TASK )  MT_ProcessEvent,#endif  APS_event_loop,#if defined ( ZIGBEE_FRAGMENTATION )  APSF_ProcessEvent,#endif  ZDApp_event_loop,#if defined ( ZIGBEE_FREQ_AGILITY ) || defined ( ZIGBEE_PANID_CONFLICT )  ZDNwkMgr_event_loop,#endif  <span style="color:#ff0000;">SampleApp_ProcessEvent</span>};

其中 SampleApp_ProcessEvent为我们自定义应用事件处理函数，函数名可自定义，在本次应用中该函数的原型如下：

uint16 SampleApp_ProcessEvent( uint8 task_id, uint16 events ){  afIncomingMSGPacket_t *MSGpkt;  (void)task_id;  // Intentionally unreferenced parameter  if ( events & SYS_EVENT_MSG ) //接收系统消息再进行判断  {    //接收属于本应用任务SampleApp的消息，以SampleApp_TaskID标记    MSGpkt = (afIncomingMSGPacket_t *)osal_msg_receive( SampleApp_TaskID );    while ( MSGpkt )    {      switch ( MSGpkt->hdr.event )      {        // Received when a key is pressed        case <span style="color:#ff0000;">KEY_CHANGE</span>://按键事件          HalLedBlink(HAL_LED_2, 0, 50, 200);//如果是则Led1间隔200ms闪烁          SampleApp_HandleKeys( ((keyChange_t *)MSGpkt)->state, ((keyChange_t *)MSGpkt)->keys );          break;        // Received when a messages is received (OTA) for this endpoint        case <span style="color:#ff0000;">AF_INCOMING_MSG_CMD:</span>//接收数据事件,调用函数AF_DataRequest()接收数据          SampleApp_MessageMSGCB( MSGpkt );//调用回调函数对收到的数据进行处理          break;        // Received whenever the device changes state in the network        case <span style="color:#ff0000;">ZDO_STATE_CHANGE:</span>          //只要网络状态发生改变，就通过ZDO_STATE_CHANGE事件通知所有的任务。          //同时完成对协调器，路由器，终端的设置          SampleApp_NwkState = (devStates_t)(MSGpkt->hdr.status);          //if ( (SampleApp_NwkState == DEV_ZB_COORD)//实验中协调器只接收数据所以取消发送事件          if ( (SampleApp_NwkState == DEV_ROUTER) || (SampleApp_NwkState == DEV_END_DEVICE) )          {            // Start sending the periodic message in a regular interval.            //这个定时器只是为发送周期信息开启的，设备启动初始化后从这里开始            //触发第一个周期信息的发送，然后周而复始下去            osal_start_timerEx( SampleApp_TaskID,                              SAMPLEAPP_SEND_PERIODIC_MSG_EVT,                              SAMPLEAPP_SEND_PERIODIC_MSG_TIMEOUT );          }          else          {            // Device is no longer in the network          }          break;        default:          break;      }      // Release the memory 事件处理完了，释放消息占用的内存      osal_msg_deallocate( (uint8 *)MSGpkt );      // Next - if one is available 指针指向下一个放在缓冲区的待处理的事件，      //返回while ( MSGpkt )重新处理事件，直到缓冲区没有等待处理事件为止      MSGpkt = (afIncomingMSGPacket_t *)osal_msg_receive( SampleApp_TaskID );    }    // return unprocessed events 返回未处理的事件    return (events ^ SYS_EVENT_MSG);  }

如上，红色标注部分为事件类型，当系统发生该类事件时，会进入该函数，部分事件需要注册，如KEY_CHANGE事件；
暂歇一会，明天继续，，，，，，

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