📄 os_core.c
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#else//如果只有一个事件控制块
OSEventFreeList = &OSEventTbl[0]; /* Only have ONE event control block */
OSEventFreeList->OSEventType = OS_EVENT_TYPE_UNUSED;
OSEventFreeList->OSEventPtr = (OS_EVENT *)0;//前趋指向NULL
#endif
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZATION
* INITIALIZE MISCELLANEOUS VARIABLES
*
* Description: This function is called by OSInit() to initialize miscellaneous variables.
*
* Arguments : none
*
* Returns : none
描述：由OSInit()调用去初始化各种变量
参数：无
返回：无
*********************************************************************************************************
*/
static void OS_InitMisc (void)
{
#if OS_TIME_GET_SET_EN > 0
OSTime = 0L; /* Clear the 32-bit system clock */
#endif//清除32位系统时钟
OSIntNesting = 0; /* Clear the interrupt nesting counter *///中断嵌套初始化为0
OSLockNesting = 0; /* Clear the scheduling lock counter */
//清除调度锁定计数器
OSTaskCtr = 0; /* Clear the number of tasks */
//初始化任务计数器
OSRunning = FALSE; /* Indicate that multitasking not started */
//表示多任务处理还没有开始
OSCtxSwCtr = 0; /* Clear the context switch counter */
//任务转换计数器为0
OSIdleCtr = 0L; /* Clear the 32-bit idle counter */
//清除32位空闲计数器
#if (OS_TASK_STAT_EN > 0) && (OS_TASK_CREATE_EXT_EN > 0)
OSIdleCtrRun = 0L;
OSIdleCtrMax = 0L;
OSStatRdy = FALSE; /* Statistic task is not ready */
//统计任务还没有准备好呢！
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZATION
* INITIALIZE THE READY LIST
*
* Description: This function is called by OSInit() to initialize the Ready List.
*
* Arguments : none
*
* Returns : none
初始化就绪列表
描述：由OSInit()调用，初始化就绪列表
参数：无
返回：无
*********************************************************************************************************
*/
static void OS_InitRdyList (void)
{
INT16U i;
INT8U *prdytbl;
OSRdyGrp = 0x00; /* Clear the ready list */
//等待列表清零
prdytbl = &OSRdyTbl[0];//得到就绪任务方框表首地址
for (i = 0; i < OS_RDY_TBL_SIZE; i++) {
*prdytbl++ = 0x00;//每一组都清零
}
OSPrioCur = 0;//当前任务优先级
OSPrioHighRdy = 0;//最高优先级任务的优先级
OSTCBHighRdy = (OS_TCB *)0; //指向最高优先级TCB指针
OSTCBCur = (OS_TCB *)0;//当前运行任务TCB指针
}
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZATION
* CREATING THE IDLE TASK
*
* Description: This function creates the Idle Task.
*
* Arguments : none
*
* Returns : none
建立空闲任务
描述：这个函数建立空闲任务
参数：无
返回：无
*********************************************************************************************************
*/
static void OS_InitTaskIdle (void)
{
#if OS_TASK_CREATE_EXT_EN > 0//包含创建任务代码OS_TASK_CREATE_EXT_EN
#if OS_STK_GROWTH == 1//堆栈从高到低
(void)OSTaskCreateExt(OS_TaskIdle,//建立空闲任务
(void *)0, /* No arguments passed to OS_TaskIdle() */
//pdata为零，没有参数传递表示没有参数传给OS_TaskIdle()
&OSTaskIdleStk[OS_TASK_IDLE_STK_SIZE - 1], /* Set Top-Of-Stack */
//设置栈顶地址
OS_IDLE_PRIO, /* Lowest priority level */
//优先级
OS_TASK_IDLE_ID,//任务ID
&OSTaskIdleStk[0], /* Set Bottom-Of-Stack */
//设置栈底
OS_TASK_IDLE_STK_SIZE,//堆栈大小，即进口宽度
(void *)0, /* No TCB extension */
//无TCB扩展
OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR);/* Enable stack checking + clear stack */
//允许堆栈检测/清除堆栈
#else//堆栈从低到高
(void)OSTaskCreateExt(OS_TaskIdle,
(void *)0, /* No arguments passed to OS_TaskIdle() */
&OSTaskIdleStk[0], /* Set Top-Of-Stack */
//与上面相反
OS_IDLE_PRIO, /* Lowest priority level */
OS_TASK_IDLE_ID,
&OSTaskIdleStk[OS_TASK_IDLE_STK_SIZE - 1], /* Set Bottom-Of-Stack */
//与上面相反
OS_TASK_IDLE_STK_SIZE,
(void *)0, /* No TCB extension */
OS_TASK_OPT_STK_CHK | OS_TASK_OPT_STK_CLR);/* Enable stack checking + clear stack */
#endif
#else//不包含创建任务代码OS_TASK_CREATE_EXT_EN
#if OS_STK_GROWTH == 1//堆栈从高到低
(void)OSTaskCreate(OS_TaskIdle,
(void *)0,
&OSTaskIdleStk[OS_TASK_IDLE_STK_SIZE - 1],
OS_IDLE_PRIO);
#else//堆栈从低到高
(void)OSTaskCreate(OS_TaskIdle,
(void *)0,
&OSTaskIdleStk[0],
OS_IDLE_PRIO);
#endif
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZATION
* CREATING THE STATISTIC TASK
*
* Description: This function creates the Statistic Task.
*
* Arguments : none
*
* Returns : none
建立统计任务
描述：建立统计任务
参数：无
返回：无
*********************************************************************************************************
*/
//这个函数同上面一样差不多
#if OS_TASK_STAT_EN > 0
static void OS_InitTaskStat (void)
{
#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 */
//比空闲任务优先级高一
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
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZATION
* INITIALIZE THE FREE LIST OF TASK CONTROL BLOCKS
*
* Description: This function is called by OSInit() to initialize the free list of OS_TCBs.
*
* Arguments : none
*
* Returns : none
初始化TCB链表
描述：由OSInit()调用，初始化OS_TCBs空闲链表
*********************************************************************************************************
*/
static void OS_InitTCBList (void)
{
INT8U i;
OS_TCB *ptcb1;
OS_TCB *ptcb2;
OSTCBList = (OS_TCB *)0; /* TCB Initialization */
//初始化双向TCB链表
for (i = 0; i < (OS_LOWEST_PRIO + 1); i++) { /* Clear the priority table */
OSTCBPrioTbl[i] = (OS_TCB *)0;
}//清除优先级方框表
ptcb1 = &OSTCBTbl[0];
ptcb2 = &OSTCBTbl[1];//取地址
for (i = 0; i < (OS_MAX_TASKS + OS_N_SYS_TASKS - 1); i++) { /* Init. list of free TCBs */
ptcb1->OSTCBNext = ptcb2;
ptcb1++;
ptcb2++;//把它们链在一起
}
ptcb1->OSTCBNext = (OS_TCB *)0; /* Last OS_TCB *///最后一个指向空指针
OSTCBFreeList = &OSTCBTbl[0];//空表指向第一个地址
}
/*$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())
*********************************************************************************************************
*/
/*
************************************************************************************************
调度程序
描述：这个函数由其它ucosII版本服务调用去检查是否一个新的，高优先级的任务将准备运行。
这个功能由任务等级代码唤醒，它不用于从中断服务程序中重新安排代码。
参数：无
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