📄 os_core.c
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/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
* CORE FUNCTIONS
*
* (c) Copyright 1992-2001, Jean J. Labrosse, Weston, FL
* All Rights Reserved
*
* File : OS_CORE.C
* By : Jean J. Labrosse
*********************************************************************************************************
*/
#ifndef OS_MASTER_FILE
#define OS_GLOBALS
#include "includes.h"
#endif
/*
*********************************************************************************************************
* MAPPING TABLE TO MAP BIT POSITION TO BIT MASK
*
* Note: Index into table is desired bit position, 0..7
* Indexed value corresponds to bit mask
*********************************************************************************************************
*/
INT8U const OSMapTbl[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
/*
*********************************************************************************************************
* PRIORITY RESOLUTION TABLE
*
* Note: Index into table is bit pattern to resolve highest priority
* Indexed value corresponds to highest priority bit position (i.e. 0..7)
*********************************************************************************************************
*/
INT8U const OSUnMapTbl[] = {
0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0
};
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZATION
*
* Description: This function is used to initialize the internals of uC/OS-II and MUST be called prior to
* creating any uC/OS-II object and, prior to calling OSStart().
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/
void OSInit (void)
{
INT16U i;
INT8U *prdytbl;
OS_TCB *ptcb1;
OS_TCB *ptcb2;
#if (OS_EVENT_EN > 0) && (OS_MAX_EVENTS > 1)
OS_EVENT *pevent1;
OS_EVENT *pevent2;
#endif
#if OS_VERSION >= 204
OSInitHookBegin(); /* Call port specific initialization code */
#endif
#if OS_TIME_GET_SET_EN > 0
OSTime = 0L; /* Clear the 32-bit system clock */
#endif
OSIntNesting = 0; /* Clear the interrupt nesting counter */
OSLockNesting = 0; /* Clear the scheduling lock counter */
OSTaskCtr = 0; /* Clear the number of tasks */
OSRunning = FALSE; /* Indicate that multitasking not started */
OSIdleCtr = 0L; /* Clear the 32-bit idle counter */
#if (OS_TASK_STAT_EN > 0) && (OS_TASK_CREATE_EXT_EN > 0)
OSIdleCtrRun = 0L;
OSIdleCtrMax = 0L;
OSStatRdy = FALSE; /* Statistic task is not ready */
#endif
OSCtxSwCtr = 0; /* Clear the context switch counter */
OSRdyGrp = 0x00; /* Clear the ready list */
prdytbl = &OSRdyTbl[0];
for (i = 0; i < OS_RDY_TBL_SIZE; i++) {
*prdytbl++ = 0x00;
}
OSPrioCur = 0;
OSPrioHighRdy = 0;
OSTCBHighRdy = (OS_TCB *)0; /* TCB Initialization */
OSTCBCur = (OS_TCB *)0;
OSTCBList = (OS_TCB *)0;
for (i = 0; i < (OS_LOWEST_PRIO + 1); i++) { /* Clear the priority table */
OSTCBPrioTbl[i] = (OS_TCB *)0;
}
ptcb1 = &OSTCBTbl[0];
ptcb2 = &OSTCBTbl[1];
for (i = 0; i < (OS_MAX_TASKS + OS_N_SYS_TASKS - 1); i++) { /* Init. list of free TCBs */
ptcb1->OSTCBNext = ptcb2;
ptcb1++;
ptcb2++;
}
ptcb1->OSTCBNext = (OS_TCB *)0; /* Last OS_TCB */
OSTCBFreeList = &OSTCBTbl[0];
#if (OS_EVENT_EN > 0) && (OS_MAX_EVENTS > 0)
#if OS_MAX_EVENTS == 1
OSEventFreeList = &OSEventTbl[0]; /* Only have ONE event control block */
OSEventFreeList->OSEventType = OS_EVENT_TYPE_UNUSED;
OSEventFreeList->OSEventPtr = (OS_EVENT *)0;
#else
pevent1 = &OSEventTbl[0];
pevent2 = &OSEventTbl[1];
for (i = 0; i < (OS_MAX_EVENTS - 1); i++) { /* Init. list of free EVENT control blocks */
pevent1->OSEventType = OS_EVENT_TYPE_UNUSED;
pevent1->OSEventPtr = pevent2;
pevent1++;
pevent2++;
}
pevent1->OSEventType = OS_EVENT_TYPE_UNUSED;
pevent1->OSEventPtr = (OS_EVENT *)0;
OSEventFreeList = &OSEventTbl[0];
#endif
#endif
#if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0)
OS_FlagInit(); /* Initialize the event flag structures */
#endif
#if (OS_Q_EN > 0) && (OS_MAX_QS > 0)
OS_QInit(); /* Initialize the message queue structures */
#endif
#if (OS_MEM_EN > 0) && (OS_MAX_MEM_PART > 0)
OS_MemInit(); /* Initialize the memory manager */
#endif
/* ------------------------------------- CREATION OF 'IDLE' TASK --------------------------------------- */
#if OS_TASK_CREATE_EXT_EN > 0
#if OS_STK_GROWTH == 1
(void)OSTaskCreateExt(OS_TaskIdle,
(void *)0, /* No arguments passed to OS_TaskIdle() */
&OSTaskIdleStk[OS_TASK_IDLE_STK_SIZE - 1], /* Set Top-Of-Stack */
OS_IDLE_PRIO, /* Lowest priority level */
OS_TASK_IDLE_ID,
&OSTaskIdleStk[0], /* Set Bottom-Of-Stack */
OS_TASK_IDLE_STK_SIZE,
(void *)0, /* No TCB extension */
OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR);/* Enable stack checking + clear stack */
#else
(void)OSTaskCreateExt(OS_TaskIdle,
(void *)0, /* No arguments passed to OS_TaskIdle() */
&OSTaskIdleStk[0], /* Set Top-Of-Stack */
OS_IDLE_PRIO, /* Lowest priority level */
OS_TASK_IDLE_ID,
&OSTaskIdleStk[OS_TASK_IDLE_STK_SIZE - 1], /* Set Bottom-Of-Stack */
OS_TASK_IDLE_STK_SIZE,
(void *)0, /* No TCB extension */
OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR);/* Enable stack checking + clear stack */
#endif
#else
#if OS_STK_GROWTH == 1
(void)OSTaskCreate(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
#endif
/* ------------------------------- CREATION OF 'STATISTIC' TASK ---------------------------------- */
#if OS_TASK_STAT_EN > 0
#if OS_TASK_CREATE_EXT_EN > 0
#if OS_STK_GROWTH == 1
(void)OSTaskCreateExt(OS_TaskStat,
(void *)0, /* No args passed to OS_TaskStat()*/
&OSTaskStatStk[OS_TASK_STAT_STK_SIZE - 1], /* Set Top-Of-Stack */
OS_STAT_PRIO, /* One higher than the idle task */
OS_TASK_STAT_ID,
&OSTaskStatStk[0], /* Set Bottom-Of-Stack */
OS_TASK_STAT_STK_SIZE,
(void *)0, /* No TCB extension */
OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR); /* Enable stack checking + clear */
#else
(void)OSTaskCreateExt(OS_TaskStat,
(void *)0, /* No args passed to OS_TaskStat()*/
&OSTaskStatStk[0], /* Set Top-Of-Stack */
OS_STAT_PRIO, /* One higher than the idle task */
OS_TASK_STAT_ID,
&OSTaskStatStk[OS_TASK_STAT_STK_SIZE - 1], /* Set Bottom-Of-Stack */
OS_TASK_STAT_STK_SIZE,
(void *)0, /* No TCB extension */
OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR); /* Enable stack checking + clear */
#endif
#else
#if OS_STK_GROWTH == 1
(void)OSTaskCreate(OS_TaskStat,
(void *)0, /* No args passed to OS_TaskStat()*/
&OSTaskStatStk[OS_TASK_STAT_STK_SIZE - 1], /* Set Top-Of-Stack */
OS_STAT_PRIO); /* One higher than the idle task */
#else
(void)OSTaskCreate(OS_TaskStat,
(void *)0, /* No args passed to OS_TaskStat()*/
&OSTaskStatStk[0], /* Set Top-Of-Stack */
OS_STAT_PRIO); /* One higher than the idle task */
#endif
#endif
#endif
#if OS_VERSION >= 204
OSInitHookEnd(); /* Call port specific init. code */
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* ENTER ISR
*
* Description: This function is used to notify uC/OS-II that you are about to service an interrupt
* service routine (ISR). This allows uC/OS-II to keep track of interrupt nesting and thus
* only perform rescheduling at the last nested ISR.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) Your ISR can directly increment OSIntNesting without calling this function because
* 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();
if (OSIntNesting < 255) {
OSIntNesting++; /* Increment ISR nesting level */
}
OS_EXIT_CRITICAL();
}
/*$PAGE*/
/*
*********************************************************************************************************
* EXIT ISR
*
* Description: This function is used to notify uC/OS-II that you have completed serviving an ISR. When
* the last nested ISR has completed, uC/OS-II will call the scheduler to determine whether
* a new, high-priority task, is ready to run.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) You MUST invoke OSIntEnter() and OSIntExit() in pair. In other words, for every call
* to OSIntEnter() at the beginning of the ISR you MUST have a call to OSIntExit() at the
* end of the ISR.
* 2) Rescheduling is prevented when the scheduler is locked (see OSSchedLock())
*********************************************************************************************************
*/
void OSIntExit (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_ENTER_CRITICAL();
if (OSIntNesting > 0) { /* Prevent OSIntNesting from wrapping */
OSIntNesting--;
}
if ((OSIntNesting == 0) && (OSLockNesting == 0)) { /* Reschedule only if all ISRs complete ... */
OSIntExitY = OSUnMapTbl[OSRdyGrp]; /* ... and not locked. */
OSPrioHighRdy = (INT8U)((OSIntExitY << 3) + OSUnMapTbl[OSRdyTbl[OSIntExitY]]);
if (OSPrioHighRdy != OSPrioCur) { /* No Ctx Sw if current task is highest rdy */
OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy];
OSCtxSwCtr++; /* Keep track of the number of context switches */
OSIntCtxSw(); /* Perform interrupt level context switch */
}
}
OS_EXIT_CRITICAL();
}
/*$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
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