os_core.c

是一个ucos-ii移植到44B0上的例子

*
* Returns    : none
*
* Notes      : 1) You MUST invoke OSSchedLock() and OSSchedUnlock() in pair.  In other words, for every
*                 call to OSSchedLock() you MUST have a call to OSSchedUnlock().
*********************************************************************************************************
*/

#if OS_SCHED_LOCK_EN > 0
void  OSSchedLock (void)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    
    
    if (OSRunning == TRUE) {                     /* Make sure multitasking is running                  */
        OS_ENTER_CRITICAL();
        if (OSLockNesting < 255) {               /* Prevent OSLockNesting from wrapping back to 0      */
            OSLockNesting++;                     /* Increment lock nesting level                       */
        }
        OS_EXIT_CRITICAL();
    }
}
#endif    

/*$PAGE*/
/*
*********************************************************************************************************
*                                          ENABLE SCHEDULING
*
* Description: This function is used to re-allow rescheduling.
*
* Arguments  : none
*
* Returns    : none
*
* Notes      : 1) You MUST invoke OSSchedLock() and OSSchedUnlock() in pair.  In other words, for every
*                 call to OSSchedLock() you MUST have a call to OSSchedUnlock().
*********************************************************************************************************
*/

#if OS_SCHED_LOCK_EN > 0
void  OSSchedUnlock (void)
{
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register */
    OS_CPU_SR  cpu_sr;
#endif    
    
    
    if (OSRunning == TRUE) {                                   /* Make sure multitasking is running    */
        OS_ENTER_CRITICAL();
        if (OSLockNesting > 0) {                               /* Do not decrement if already 0        */
            OSLockNesting--;                                   /* Decrement lock nesting level         */
            if ((OSLockNesting == 0) && (OSIntNesting == 0)) { /* See if sched. enabled and not an ISR */
                OS_EXIT_CRITICAL();
                OS_Sched();                                    /* See if a HPT is ready                */
            } else {
                OS_EXIT_CRITICAL();
            }
        } else {
            OS_EXIT_CRITICAL();
        }
    }
}
#endif    

/*$PAGE*/
/*
*********************************************************************************************************
*                                          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 TRUE.
*********************************************************************************************************
*/

void  OSStart (void)
{
    INT8U y;
    INT8U x;


    if (OSRunning == FALSE) {
        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;
#endif    
    
    
    OSTimeDly(2);                                /* Synchronize with clock tick                        */
    OS_ENTER_CRITICAL();
    OSIdleCtr    = 0L;                           /* Clear idle counter                                 */
    OS_EXIT_CRITICAL();
    OSTimeDly(OS_TICKS_PER_SEC);                 /* Determine MAX. idle counter value for 1 second     */
    OS_ENTER_CRITICAL();
    OSIdleCtrMax = OSIdleCtr;                    /* Store maximum idle counter count in 1 second       */
    OSStatRdy    = 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)
{
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register */
    OS_CPU_SR  cpu_sr;
#endif    
    OS_TCB    *ptcb;


    OSTimeTickHook();                                      /* Call user definable hook                 */
#if OS_TIME_GET_SET_EN > 0   
    OS_ENTER_CRITICAL();                                   /* Update the 32-bit tick counter           */
    OSTime++;
    OS_EXIT_CRITICAL();
#endif    
    ptcb = OSTCBList;                                      /* Point at first TCB in TCB list           */
    while (ptcb->OSTCBPrio != OS_IDLE_PRIO) {              /* Go through all TCBs in TCB list          */
        OS_ENTER_CRITICAL();
        if (ptcb->OSTCBDly != 0) {                         /* Delayed or waiting for event with TO     */
            if (--ptcb->OSTCBDly == 0) {                   /* Decrement nbr of ticks to end of delay   */
                if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) == 0x00) {   /* Is task suspended?             */
                    OSRdyGrp               |= ptcb->OSTCBBitY; /* No,  Make task Rdy to Run (timed out)*/
                    OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
                } else {                                       /* Yes, Leave 1 tick to prevent ...     */
                    ptcb->OSTCBDly = 1;                        /* ... loosing the task when the ...    */
                }                                              /* ... suspension is removed.           */
            }
        }
        ptcb = ptcb->OSTCBNext;                                /* Point at next TCB in TCB list        */
        OS_EXIT_CRITICAL();
    }
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                             GET VERSION
*
* Description: This function is used to return the version number of uC/OS-II.  The returned value
*              corresponds to uC/OS-II's version number multiplied by 100.  In other words, version 2.00
*              would be returned as 200.
*
* Arguments  : none
*
* Returns    : the version number of uC/OS-II multiplied by 100.
*********************************************************************************************************
*/

INT16U  OSVersion (void)
{
    return (OS_VERSION);
}

/*$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*/
/*
*********************************************************************************************************
*                             MAKE TASK READY TO RUN BASED ON EVENT OCCURING
*
* Description: This function is called by other uC/OS-II services and is used to ready a task that was
*              waiting for an event to occur.
*
* Arguments  : pevent    is a pointer to the event control block corresponding to the event.
*
*              msg       is a pointer to a message.  This pointer is used by message oriented services
*                        such as MAILBOXEs and QUEUEs.  The pointer is not used when called by other
*                        service functions.
*
*              msk       is a mask that is used to clear the status byte of the TCB.  For example,
*                        OSSemPost() will pass OS_STAT_SEM, OSMboxPost() will pass OS_STAT_MBOX etc.
*
* Returns    : none
*
* Note       : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
#if OS_EVENT_EN > 0
INT8U  OS_EventTaskRdy (OS_EVENT *pevent, void *msg, INT8U msk)
{
    OS_TCB *ptcb;
    INT8U   x;
    INT8U   y;
    INT8U   bitx;
    INT8U   bity;
    INT8U   prio;


    y    = OSUnMapTbl[pevent->OSEventGrp];            /* Find highest prio. task waiting for message   */
    bity = OSMapTbl[y];
    x    = OSUnMapTbl[pevent->OSEventTbl[y]];
    bitx = OSMapTbl[x];
    prio = (INT8U)((y << 3) + x);                     /* Find priority of task getting the msg         */
    if ((pevent->OSEventTbl[y] &= ~bitx) == 0x00) {   /* Remove this task from the waiting list        */
        pevent->OSEventGrp &= ~bity;                  /* Clr group bit if this was only task pending   */
    }
    ptcb                 =  OSTCBPrioTbl[prio];       /* Point to this task's OS_TCB                   */
    ptcb->OSTCBDly       =  0;                        /* Prevent OSTimeTick() from readying task       */
    ptcb->OSTCBEventPtr  = (OS_EVENT *)0;             /* Unlink ECB from this task                     */
#if ((OS_Q_EN > 0) && (OS_MAX_QS > 0)) || (OS_MBOX_EN > 0)
    ptcb->OSTCBMsg       = msg;                       /* Send message directly to waiting task         */
#else
    msg                  = msg;                       /* Prevent compiler warning if not used          */
#endif
    ptcb->OSTCBStat     &= ~msk;                      /* Clear bit associated with event type          */
    if (ptcb->OSTCBStat == OS_STAT_RDY) {             /* See if task is ready (could be susp'd)        */
        OSRdyGrp        |=  bity;                     /* Put task in the ready to run list             */
        OSRdyTbl[y]     |=  bitx;
    }
    return (prio);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                   MAKE TASK WAIT FOR EVENT TO OCCUR
*
* Description: This function is called by other uC/OS-II services to suspend a task because an event has
*              not occurred.
*
* Arguments  : pevent   is a pointer to the event control block for which the task will be waiting for.
*
* Returns    : none
*
* Note       : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
#if OS_EVENT_EN > 0
void  OS_EventTaskWait (OS_EVENT *pevent)
{
    OSTCBCur->OSTCBEventPtr = pevent;            /* Store pointer to event control block in TCB        */
    if ((OSRdyTbl[OSTCBCur->OSTCBY] &= ~OSTCBCur->OSTCBBitX) == 0x00) {   /* Task no longer ready      */
        OSRdyGrp &= ~OSTCBCur->OSTCBBitY;        /* Clear event grp bit if this was only task pending  */
    }
    pevent->OSEventTbl[OSTCBCur->OSTCBY] |= OSTCBCur->OSTCBBitX;          /* Put task in waiting list  */
    pevent->OSEventGrp                   |= OSTCBCur->OSTCBBitY;
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                              MAKE TASK READY TO RUN BASED ON EVENT TIMEOUT
*
* Description: This function is called by other uC/OS-II services to make a task ready to run because a
*              timeout occurred.
*
* Arguments  : pevent   is a pointer to the event control block which is readying a task.
*
* Returns    : none
*
* Note       : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/