os_cpu_c.c

ARM_CORTEX-M3应用实例开发详解光盘

* Note(s)    : 1) Interrupts are enabled when your task starts executing.
*              2) All tasks run in Thread mode, using process stack.
*********************************************************************************************************
*/

OS_STK *OSTaskStkInit (void (*task)(void *p_arg), void *p_arg, OS_STK *ptos, INT16U opt)
{
    OS_STK *stk;


    (void)opt;                                   /* 'opt' is not used, prevent warning                 */
    stk       = ptos;                            /* Load stack pointer                                 */

                                                 /* Registers stacked as if auto-saved on exception    */
    *(stk)    = (INT32U)0x01000000L;             /* xPSR                                               */
    *(--stk)  = (INT32U)task;                    /* Entry Point                                        */
    *(--stk)  = (INT32U)OSTaskEndSelf;
    // *(--stk)  = (INT32U)0xFFFFFFFEL;             /* R14 (LR) (init value will cause fault if ever used)*/
    *(--stk)  = (INT32U)0x12121212L;             /* R12                                                */
    *(--stk)  = (INT32U)0x03030303L;             /* R3                                                 */
    *(--stk)  = (INT32U)0x02020202L;             /* R2                                                 */
    *(--stk)  = (INT32U)0x01010101L;             /* R1                                                 */
    *(--stk)  = (INT32U)p_arg;                   /* R0 : argument                                      */

                                                 /* Remaining registers saved on process stack         */
    *(--stk)  = (INT32U)0x11111111L;             /* R11                                                */
    *(--stk)  = (INT32U)0x10101010L;             /* R10                                                */
    *(--stk)  = (INT32U)0x09090909L;             /* R9                                                 */
    *(--stk)  = (INT32U)0x08080808L;             /* R8                                                 */
    *(--stk)  = (INT32U)0x07070707L;             /* R7                                                 */
    *(--stk)  = (INT32U)0x06060606L;             /* R6                                                 */
    *(--stk)  = (INT32U)0x05050505L;             /* R5                                                 */
    *(--stk)  = (INT32U)0x04040404L;             /* R4                                                 */

    return (stk);
}

/*
*********************************************************************************************************
*                                           TASK SWITCH HOOK
*
* Description: This function is called when a task switch is performed.  This allows you to perform other
*              operations during a context switch.
*
* Arguments  : none
*
* Note(s)    : 1) Interrupts are disabled during this call.
*              2) It is assumed that the global pointer 'OSTCBHighRdy' points to the TCB of the task that
*                 will be 'switched in' (i.e. the highest priority task) and, 'OSTCBCur' points to the
*                 task being switched out (i.e. the preempted task).
*********************************************************************************************************
*/
#if (OS_CPU_HOOKS_EN > 0) && (OS_TASK_SW_HOOK_EN > 0)
void  OSTaskSwHook (void)
{
#if OS_APP_HOOKS_EN > 0
    App_TaskSwHook();
#endif
}
#endif

/*
*********************************************************************************************************
*                                           OS_TCBInit() HOOK
*
* Description: This function is called by OS_TCBInit() after setting up most of the TCB.
*
* Arguments  : ptcb    is a pointer to the TCB of the task being created.
*
* Note(s)    : 1) Interrupts may or may not be ENABLED during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void  OSTCBInitHook (OS_TCB *ptcb)
{
#if OS_APP_HOOKS_EN > 0
    App_TCBInitHook(ptcb);
#else
    (void)ptcb;                                  /* Prevent compiler warning                           */
#endif
}
#endif


/*
*********************************************************************************************************
*                                               TICK HOOK
*
* Description: This function is called every tick.
*
* Arguments  : none
*
* Note(s)    : 1) Interrupts may or may not be ENABLED during this call.
*********************************************************************************************************
*/
#if (OS_CPU_HOOKS_EN > 0) && (OS_TIME_TICK_HOOK_EN > 0)
void  OSTimeTickHook (void)
{
#if OS_APP_HOOKS_EN > 0
    App_TimeTickHook();
#endif

#if OS_TMR_EN > 0
    OSTmrCtr++;
    if (OSTmrCtr >= (OS_TICKS_PER_SEC / OS_TMR_CFG_TICKS_PER_SEC)) {
        OSTmrCtr = 0;
        OSTmrSignal();
    }
#endif
}
#endif



/*
*********************************************************************************************************
*                                         OS_CPU_SysTickHandler()
*
* Description: Handle the system tick (SysTick) interrupt, which is used to generate the uC/OS-II tick
*              interrupt.
*
* Arguments  : none.
*
* Note(s)    : 1) This function MUST be placed on entry 15 of the Cortex-M3 vector table.
*********************************************************************************************************
*/

void  OS_CPU_SysTickHandler (void)
{
#if OS_CRITICAL_METHOD == 3
    OS_CPU_SR  cpu_sr;
#endif

    OS_ENTER_CRITICAL();                         /* Tell uC/OS-II that we are starting an ISR          */
    OSIntNesting++;
    OS_EXIT_CRITICAL();

    OSTimeTick();                                /* Call uC/OS-II's OSTimeTick()                       */

    OSIntExit();                                 /* Tell uC/OS-II that we are leaving the ISR          */
}


/*
*********************************************************************************************************
*                                          OS_CPU_SysTickInit()
*
* Description: Initialize the SysTick.
*
* Arguments  : none.
*
* Note(s)    : 1) This function MUST be called after OSStart() & after processor initialization.
*********************************************************************************************************
*/

void  OS_CPU_SysTickInit (void)
{
    INT32U  cnts;

	cnts = OS_CPU_ClkFreq() / OS_TICKS_PER_SEC;

    OS_CPU_CM3_NVIC_ST_RELOAD = (cnts - 1);
                                                 /* Enable timer.                                      */
    OS_CPU_CM3_NVIC_ST_CTRL  |= OS_CPU_CM3_NVIC_ST_CTRL_CLK_SRC | OS_CPU_CM3_NVIC_ST_CTRL_ENABLE;
                                                 /* Enable timer interrupt.                            */
    OS_CPU_CM3_NVIC_ST_CTRL  |= OS_CPU_CM3_NVIC_ST_CTRL_INTEN;
}

INT32U  OS_CPU_ClkFreq (void)   
{   
    INT32U  ccfg;   
    INT32U  cpu_clk_freq;   
   	INT32U  tmp;   
   
    ccfg         = (INT32U)(OS_CPU_CM3_ST_RCC_CFGR);   
	switch (ccfg & 0x0C) {
	case 0x0:	  // SHI is System Clock Source.
		cpu_clk_freq =  CPU_OSC_FREQ; // 8MHz
		break;
	case 0x4:	  // SHE is System Clock Source.
		cpu_clk_freq = CPU_OSC_FREQ;
		break;
	case 0x8:	  // PLL is System Clock Source.
		cpu_clk_freq = CPU_OSC_FREQ;
		if (!((ccfg & 0x10000) && !(ccfg & 0x20000))) 
			cpu_clk_freq /= 2;
		tmp = (ccfg &(0xF<<18))>>18;
		cpu_clk_freq *= (tmp + 2) & 0xf;	
		break;
	default:
		return 0;
	}
	if (ccfg & (0x8<<4)) {
		
		tmp = ((ccfg & (0x7<<4)) >> 4);
		tmp++;
		if (tmp > 4)
			tmp += 1;
		cpu_clk_freq /= 2 << tmp;
	}
       
    return (cpu_clk_freq);   
}