typedef void * xTaskHandle;        //任务句柄
typedef enum
{
    eRunning = 0,
    eReady,
    eBlocked,
    eSuspended,
    eDeleted
} eTaskState;         //这里定义了任务可能处于的五种状态

typedef struct tskTaskControlBlock
{
	volatile portSTACK_TYPE	*pxTopOfStack;		/*< Points to the location of the last item placed on the tasks stack.  THIS MUST BE THE FIRST MEMBER OF THE TCB STRUCT. */

	#if ( portUSING_MPU_WRAPPERS == 1 )
		xMPU_SETTINGS xMPUSettings;				/*< The MPU settings are defined as part of the port layer.  THIS MUST BE THE SECOND MEMBER OF THE TCB STRUCT. */
	#endif

	xListItem				xGenericListItem;	/*< The list that the state list item of a task is reference from denotes the state of that task (Ready, Blocked, Suspended ). */
	xListItem				xEventListItem;		/*< Used to reference a task from an event list. */
	unsigned portBASE_TYPE	uxPriority;			/*< The priority of the task.  0 is the lowest priority. */
	portSTACK_TYPE			*pxStack;			/*< Points to the start of the stack. */
	signed char				pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */

	#if ( portSTACK_GROWTH > 0 )
		portSTACK_TYPE *pxEndOfStack;			/*< Points to the end of the stack on architectures where the stack grows up from low memory. */
	#endif

	#if ( portCRITICAL_NESTING_IN_TCB == 1 )
		unsigned portBASE_TYPE uxCriticalNesting; /*< Holds the critical section nesting depth for ports that do not maintain their own count in the port layer. */
	#endif

	#if ( configUSE_TRACE_FACILITY == 1 )
		unsigned portBASE_TYPE	uxTCBNumber;	/*< Stores a number that increments each time a TCB is created.  It allows debuggers to determine when a task has been deleted and then recreated. */
		unsigned portBASE_TYPE  uxTaskNumber;	/*< Stores a number specifically for use by third party trace code. */
	#endif

	#if ( configUSE_MUTEXES == 1 )
		unsigned portBASE_TYPE uxBasePriority;	/*< The priority last assigned to the task - used by the priority inheritance mechanism. */
	#endif

	#if ( configUSE_APPLICATION_TASK_TAG == 1 )
		pdTASK_HOOK_CODE pxTaskTag;
	#endif

	#if ( configGENERATE_RUN_TIME_STATS == 1 )
		unsigned long ulRunTimeCounter;			/*< Stores the amount of time the task has spent in the Running state. */
	#endif

	#if ( configUSE_NEWLIB_REENTRANT == 1 )
		/* Allocate a Newlib reent structure that is specific to this task.
		Note Newlib support has been included by popular demand, but is not
		used by the FreeRTOS maintainers themselves.  FreeRTOS is not
		responsible for resulting newlib operation.  User must be familiar with
		newlib and must provide system-wide implementations of the necessary
		stubs. Be warned that (at the time of writing) the current newlib design
		implements a system-wide malloc() that must be provided with locks. */
		struct _reent xNewLib_reent;
	#endif

} tskTCB;

void vTaskCode( void * pvParameters)
{
    for(;;)
    {
        // Task code goes here.
    }
}

portBASE_TYPE  xTaskCreate(
                    pdTASK_CODE pvTaskCode,
                    const char* const pcName,
                    unsigned short usStackDepth,
                    void *pvParameters,
                    unsigned portBASE_TYPE uxPriority,
                    xTaskHandle *pvCreatedTask
                    );

int
main(void)
{
    xTaskHandle xHandle;     //声明一个任务句柄

    xTaskCreate( vTaskCode, "TaskName", STACK_SIZE, NULL, tskIDLE_PRIORITY,
    &xHandle);              //创建任务

    vTaskStartScheduler();   //启动任务调度器
    
    for(;;);

    return 0;
}