os_core.c

ucosii for zsp400

*                 OSIntNesting has been declared 'global'.  You MUST, however, be sure that the increment
*                 is performed 'indivisibly' by your processor to ensure proper access to this critical
*                 resource.
*              2) You MUST still call OSIntExit() even though you increment OSIntNesting directly.
*              3) You MUST invoke OSIntEnter() and OSIntExit() in pair.  In other words, for every call
*                 to OSIntEnter() at the beginning of the ISR you MUST have a call to OSIntExit() at the
*                 end of the ISR.
*********************************************************************************************************
*/

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


    OS_ENTER_CRITICAL();

   /*
   LSI Logic (BDA) Modification
   S. Wright
   08/20/2001

   added check for OS running
   this prevents unpredictable behavior should ISRs start prior to OSRunning == TRUE
   */

    if (OSRunning == TRUE) {
    if (OSIntNesting < 255) {
        OSIntNesting++;                          /* Increment ISR nesting level                        */
    }
    }
    OS_EXIT_CRITICAL();
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                               EXIT ISR
*
* Description: This function is used to notify uC/OS-II that you have completed serviving an ISR.  When
*              the last nested ISR has completed, uC/OS-II will call the scheduler to determine whether
*              a new, high-priority task, is ready to run.
*
* Arguments  : none
*
* Returns    : none
*
* Notes      : 1) You MUST invoke OSIntEnter() and OSIntExit() in pair.  In other words, for every call
*                 to OSIntEnter() at the beginning of the ISR you MUST have a call to OSIntExit() at the
*                 end of the ISR.
*              2) Rescheduling is prevented when the scheduler is locked (see OSSchedLock())
*********************************************************************************************************
*/

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


    OS_ENTER_CRITICAL();

   /*
   LSI Logic (BDA) Modification
   S. Wright
   08/20/2001

   added check for OS running
   this prevents unpredictable behavior should ISRs start prior to OSRunning == TRUE
   */

    if (OSRunning == TRUE) {
    if (OSIntNesting > 0) {                            /* Prevent OSIntNesting from wrapping           */
        OSIntNesting--;
    }
    if ((OSIntNesting == 0) && (OSLockNesting == 0)) { /* Reschedule only if all ISRs complete ...     */
        OSIntExitY    = OSUnMapTbl[OSRdyGrp];          /* ... and not locked.                          */
        OSPrioHighRdy = (INT8U)((OSIntExitY << 3) + OSUnMapTbl[OSRdyTbl[OSIntExitY]]);
        if (OSPrioHighRdy != OSPrioCur) {              /* No Ctx Sw if current task is highest rdy     */
            OSTCBHighRdy  = OSTCBPrioTbl[OSPrioHighRdy];
            OSCtxSwCtr++;                              /* Keep track of the number of context switches */
            OSIntCtxSw();                              /* Perform interrupt level context switch       */
        }
    }
    }
    OS_EXIT_CRITICAL();
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                          PREVENT SCHEDULING
*
* Description: This function is used to prevent rescheduling to take place.  This allows your application
*              to prevent context switches until you are ready to permit context switching.
*
* 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  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;


   /*
   LSI Logic (BDA) Modification
   S. Wright
   08/20/2001

   added enabling/disabling of OSTimeTickHook() call
   */