os_core.c

UCOS最小系统。能在单片机上闪烁LED。支持2个led闪烁。

/*
*********************************************************************************************************
*                                          START MULTITASKING
*
* Description: This function is used to start the multitasking process which lets uC/OS-II manages the
*              task that you have created.  Before you can call OSStart(), you MUST have called OSInit()
*              and you MUST have created at least one task.
*
* Arguments  : none
*
* Returns    : none
*
* Note       : OSStartHighRdy() MUST:
*                 a) Call OSTaskSwHook() then,
*                 b) Set OSRunning to OS_TRUE.
*                 c) Load the context of the task pointed to by OSTCBHighRdy.
*                 d_ Execute the task.
*********************************************************************************************************
*/

void  OSStart (void)  reentrant
{ INT8U x ,y;
    if (OSRunning == FALSE) {
        //OS_SchedNew();                               /* Find highest priority's task priority number   */
        y             = OSUnMapTbl[OSRdyGrp];        /* Find highest priority's task priority number   */
        x             = OSUnMapTbl[OSRdyTbl[y]];
        OSPrioHighRdy = (INT8U)((y << 3) + x);
	 OSPrioCur     = OSPrioHighRdy;
        OSTCBHighRdy  = OSTCBPrioTbl[OSPrioHighRdy]; /* Point to highest priority task ready to run    */
        OSTCBCur      = OSTCBHighRdy;
        OSStartHighRdy();                            /* Execute target specific code to start task     */
    }
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                        STATISTICS INITIALIZATION
*
* Description: This function is called by your application to establish CPU usage by first determining
*              how high a 32-bit counter would count to in 1 second if no other tasks were to execute
*              during that time.  CPU usage is then determined by a low priority task which keeps track
*              of this 32-bit counter every second but this time, with other tasks running.  CPU usage is
*              determined by:
*
*                                             OSIdleCtr
*                 CPU Usage (%) = 100 * (1 - ------------)
*                                            OSIdleCtrMax
*
* Arguments  : none
*
* Returns    : none
*********************************************************************************************************
*/

#if OS_TASK_STAT_EN > 0
void  OSStatInit (void)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr = 0;
#endif



    OSTimeDly(2);                                /* Synchronize with clock tick                        */
    OS_ENTER_CRITICAL();
    OSIdleCtr    = 0L;                           /* Clear idle counter                                 */
    OS_EXIT_CRITICAL();
    OSTimeDly(OS_TICKS_PER_SEC / 10);            /* Determine MAX. idle counter value for 1/10 second  */
    OS_ENTER_CRITICAL();
    OSIdleCtrMax = OSIdleCtr;                    /* Store maximum idle counter count in 1/10 second    */
    OSStatRdy    = OS_TRUE;
    OS_EXIT_CRITICAL();
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                         PROCESS SYSTEM TICK
*
* Description: This function is used to signal to uC/OS-II the occurrence of a 'system tick' (also known
*              as a 'clock tick').  This function should be called by the ticker ISR but, can also be
*              called by a high priority task.
*
* Arguments  : none
*
* Returns    : none
*********************************************************************************************************
*/

void OSTimeTick (void) reentrant
{
	OS_TCB *ptcb;
	ptcb = OSTCBList; //point to the TCB list
	while(ptcb->OSTCBPrio!=OS_IDLE_PRIO) //GO through the tcb list
		{ 
		  OS_ENTER_CRITICAL( );
		  if (ptcb->OSTCBDly!=0)
		  	{
			  if(--ptcb->OSTCBDly==0)
			  	{
				  if((ptcb->OSTCBStat & OS_STAT_SUSPEND) == OS_STAT_RDY)
				  	{
					  OSRdyGrp              |=ptcb->OSTCBBitY;
					  OSRdyTbl[ptcb->OSTCBY]|=ptcb->OSTCBBitX;
                     } 
				   else
				      { ptcb->OSTCBDly =1;  //如果任务延时已经到了
					   }                    //但任务还在被挂起，延时置1
				 }
			 }
		   ptcb = ptcb->OSTCBNext;
		   OS_ENTER_CRITICAL( );
		  }//END WHILE
    OS_ENTER_CRITICAL( );
	OSTime++;
	OS_EXIT_CRITICAL( );
 }

/*$PAGE*/
/*
*********************************************************************************************************
*                                            DUMMY FUNCTION
*
* Description: This function doesn't do anything.  It is called by OSTaskDel().
*
* Arguments  : none
*
* Returns    : none
*********************************************************************************************************
*/

#if OS_TASK_DEL_EN > 0
void  OS_Dummy (void)
{
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                             INITIALIZATION
*                                         CREATING THE IDLE TASK
*
* Description: This function creates the Idle Task.
*
* Arguments  : none
*
* Returns    : none
*********************************************************************************************************
*/

void OS_InitTaskIdle(void) reentrant
{
  #if OS_STK_GROWTH == 1
		(void)0STaskCreate(OS_TaskIdle,
	                     (void*)0,
						 &OSTaskIdleStk[OS_TASK_IDLE_STK_SIZE-1],
						 OS_IDLE_PRIO);
  #else
		(void)OSTaskCreate(OS_TaskIdle,
	                     (void*)0,
						 &OSTaskIdleStk[0],
						 OS_IDLE_PRIO);
  #endif
  }
  
      





/*$PAGE*/
/*
*********************************************************************************************************
*                                        CLEAR A SECTION OF MEMORY
*
* Description: This function is called by other uC/OS-II services to clear a contiguous block of RAM.
*
* Arguments  : pdest    is the start of the RAM to clear (i.e. write 0x00 to)
*
*              size     is the number of bytes to clear.
*
* Returns    : none
*
* Notes      : 1) This function is INTERNAL to uC/OS-II and your application should not call it.
*              2) Note that we can only clear up to 64K bytes of RAM.  This is not an issue because none
*                 of the uses of this function gets close to this limit.
*              3) The clear is done one byte at a time since this will work on any processor irrespective
*                 of the alignment of the destination.
*********************************************************************************************************
*/

void  OS_MemClr (INT8U *pdest, INT16U size)
{
    while (size > 0) {
        *pdest++ = (INT8U)0;
        size--;
    }
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                        COPY A BLOCK OF MEMORY
*
* Description: This function is called by other uC/OS-II services to copy a block of memory from one
*              location to another.
*
* Arguments  : pdest    is a pointer to the 'destination' memory block
*
*              psrc     is a pointer to the 'source'      memory block
*
*              size     is the number of bytes to copy.
*
* Returns    : none
*
* Notes      : 1) This function is INTERNAL to uC/OS-II and your application should not call it.  There is
*                 no provision to handle overlapping memory copy.  However, that's not a problem since this
*                 is not a situation that will happen.
*              2) Note that we can only copy up to 64K bytes of RAM
*              3) The copy is done one byte at a time since this will work on any processor irrespective
*                 of the alignment of the source and destination.
*********************************************************************************************************
*/

void  OS_MemCopy (INT8U *pdest, INT8U *psrc, INT16U size)
{
    while (size > 0) {
        *pdest++ = *psrc++;
        size--;
    }
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                              SCHEDULER
*
* Description: This function is called by other uC/OS-II services to determine whether a new, high
*              priority task has been made ready to run.  This function is invoked by TASK level code
*              and is not used to reschedule tasks from ISRs (see OSIntExit() for ISR rescheduling).
*
* Arguments  : none
*
* Returns    : none
*
* Notes      : 1) This function is INTERNAL to uC/OS-II and your application should not call it.
*              2) Rescheduling is prevented when the scheduler is locked (see OS_SchedLock())
*********************************************************************************************************
*/

void  OS_Sched (void) reentrant
{   INT8U y;
    OS_ENTER_CRITICAL();
    if (OSIntNesting == 0) {                           /* Schedule only if all ISRs done and ...       */
        if (OSLockNesting == 0) {                      /* ... scheduler is not locked                  */
            //OS_SchedNew();
             y             = OSUnMapTbl[OSRdyGrp];    /* Get pointer to highest priority task ready to run  */
             OSPrioHighRdy = (INT8U)((y << 3) + OSUnMapTbl[OSRdyTbl[y]]);
            if (OSPrioHighRdy != OSPrioCur) {          /* No Ctx Sw if current task is highest rdy     */
                OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy];
#if OS_TASK_PROFILE_EN > 0
                OSTCBHighRdy->OSTCBCtxSwCtr++;         /* Inc. # of context switches to this task      */
#endif
                OSCtxSwCtr++;                          /* Increment context switch counter             */
                OS_TASK_SW();                          /* Perform a context switch                     */
            }
        }
    }
    OS_EXIT_CRITICAL();
}