μcosii源码试读1；从OSinit开始

μc的操作系统核心源码基本上都是os_core之类的文件，以前做项目的时候用过但是木有好好看过，现在不忙了可以每天晚上的时间看一点，一则巩固一下c语言的知识，二则可以为以后linux和vxworks打个基础

 

从main函数开始，除了硬件上的TargetInit(); 

初始化硬件上的端口（串口等）、PLL和中断

然后就是最主要的系统初始化函数

OSInit ();

/*
*********************************************************************************************************
* 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)
{
#if OS_VERSION >= 204
    OSInitHookBegin(); /* Call port specific initialization code */
#endif

    OS_InitMisc(); /* Initialize miscellaneous variables */

    OS_InitRdyList(); /* Initialize the Ready List */

    OS_InitTCBList(); /* Initialize the free list of OS_TCBs */

    OS_InitEventList(); /* Initialize the free list of OS_EVENTs */

#if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0)
    OS_FlagInit(); /* Initialize the event flag structures */
#endif

#if (OS_MEM_EN > 0) && (OS_MAX_MEM_PART > 0)
    OS_MemInit(); /* Initialize the memory manager */
#endif

#if (OS_Q_EN > 0) && (OS_MAX_QS > 0)
    OS_QInit(); /* Initialize the message queue structures */
#endif

    OS_InitTaskIdle(); /* Create the Idle Task */
#if OS_TASK_STAT_EN > 0
    OS_InitTaskStat(); /* Create the Statistic Task */
#endif

#if OS_TMR_EN > 0
    OSTmr_Init(); /* Initialize the Timer Manager */
#endif

#if OS_VERSION >= 204
    OSInitHookEnd(); /* Call port specific init. code */
#endif

#if OS_VERSION >= 270 && OS_DEBUG_EN > 0
    OSDebugInit();
#endif
}

如果版本号超过204u则调用函数void OSInitHookBegin (void)

 

OS_InitMisc();杂项变量初始化

/*
*********************************************************************************************************
* INITIALIZATION
* INITIALIZE MISCELLANEOUS VARIABLES
*
* Description: This function is called by OSInit() to initialize miscellaneous variables.
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/

static void OS_InitMisc (void)
{
#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 = OS_FALSE; /* Indicate that multitasking not started */

    OSCtxSwCtr = 0; /* Clear the context switch counter */
    OSIdleCtr = 0L; /* Clear the 32-bit idle counter */

#if OS_TASK_STAT_EN > 0
    OSIdleCtrRun = 0L;
    OSIdleCtrMax = 0L;
    OSStatRdy = OS_FALSE; /* Statistic task is not ready */
#endif
}

OSTime系统时钟变量

OS_EXT  volatile  INT32U  OSTime;        /* Current value of system time (in ticks) */
OSIntNesting系统中断嵌套层数变量

OS_EXT  INT8U             OSIntNesting;             /* Interrupt nesting level 

OSLockNesting系统调度锁计数器

OS_EXT  INT8U             OSLockNesting;

多任务嵌套计数器

OSTaskCtr系统创建的task的个数

OS_EXT  INT8U             OSTaskCtr;                       /* Number of tasks created  

OSRunning系统内核运行标志位

OS_EXT  BOOLEAN           OSRunning;           /* Flag indicating that kernel is running   */

OSCtxSwCtr系统上下文切换计数器

OS_EXT  INT32U            OSCtxSwCtr;    /* Counter of number of context switches  */

OSIdleCtr系统空闲计数器

OS_EXT  volatile  INT32U  OSIdleCtr;                                 /* Idle counter 

OSIdleCtrRun一秒钟内空闲计数器的有效值（据我猜测）

OS_EXT  INT32U            OSIdleCtrRun;             /* Val. reached by idle ctr at run time in 1 sec.  */

OSIdleCtrMax一秒钟内空闲计数器的最大值

OS_EXT  INT32U            OSIdleCtrMax;             /* Max. value that idle ctr can take in 1 sec.     */

OSStatRdy静态任务就绪的标志位

OS_EXT  BOOLEAN           OSStatRdy;                /* Flag indicating that the statistic task is rdy  */

 

 

 void  OS_InitRdyList (void)初始化就绪任务的数组

 

/*
*********************************************************************************************************
* INITIALIZATION
* INITIALIZE THE READY LIST
*
* Description: This function is called by OSInit() to initialize the Ready List.
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/

static void OS_InitRdyList (void)
{
    INT8U i;
#if OS_LOWEST_PRIO <= 63
    INT8U *prdytbl;
#else
    INT16U *prdytbl;
#endif


    OSRdyGrp = 0; /* Clear the ready list */
    prdytbl = &OSRdyTbl[0];
    for (i = 0; i < OS_RDY_TBL_SIZE; i++) {
        *prdytbl++ = 0;
    }

    OSPrioCur = 0;
    OSPrioHighRdy = 0;

    OSTCBHighRdy = (OS_TCB *)0;
    OSTCBCur = (OS_TCB *)0;
}

系统就绪任务表OSRdyTbl[OS_RDY_TBL_SIZE]     

#if OS_LOWEST_PRIO <= 63
OS_EXT  INT8U             OSRdyGrp;                        /* Ready list group  */
OS_EXT  INT8U             OSRdyTbl[OS_RDY_TBL_SIZE]; /* Table of tasks which are ready to run */
#else
OS_EXT  INT16U            OSRdyGrp;          /* Ready list group   */
OS_EXT  INT16U            OSRdyTbl[OS_RDY_TBL_SIZE];       /* Table of tasks which are ready to run    */
#endif