os_cpu_c.c

uCOSII 移植实例程序

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                         (c) Copyright 1998, Jean J. Labrosse, Plantation, FL
*                                          All Rights Reserved
*
*
*                                      M68HC912DG128A Specific code
*                                         (MetroWerks C/C++ V4.1)
*
* File         : OS_CPU_C.C
* By           : Jean J. Labrosse
* Port Version : V1.01
* Ported to MC68HC912DG128A : Robert F. Heslar
*********************************************************************************************************
*/

#include "INCLUDES.H"
/*
*********************************************************************************************************
*                                        INITIALIZE A TASK'S STACK
*
* Description: This function is called by either OSTaskCreate() or OSTaskCreateExt() to initialize the
*              stack frame of the task being created.  This function is highly processor specific.
*
* Arguments  : task          is a pointer to the task code
*
*              pdata         is a pointer to a user supplied data area that will be passed to the task
*                            when the task first executes.
*
*              ptos          is a pointer to the top of stack.  It is assumed that 'ptos' points to
*                            a 'free' entry on the task stack.  If OS_STK_GROWTH is set to 1 then 
*                            'ptos' will contain the HIGHEST valid address of the stack.  Similarly, if
*                            OS_STK_GROWTH is set to 0, the 'ptos' will contains the LOWEST valid address
*                            of the stack.
*
*              opt           specifies options that can be used to alter the behavior of OSTaskStkInit().
*                            (see uCOS_II.H for OS_TASK_OPT_???).
*
* Returns    : Always returns the location of the new top-of-stack' once the processor registers have
*              been placed on the stack in the proper order.
*
* Note(s)    : 1) XIRQ interrupts are disabled when your task starts executing. You can change this by 
*                 clearing BIT6 in the CCR.
*              2) The STOP instruction is disabled when your task starts executing.  You can change this
*                 by clearing BIT7 in the CCR.
*              3) The other interrupts (i.e. maskable interrupts) are enabled when your task starts
*                 executing.  You can change this by setting BIT4 in the CCR.
*              4) You can change pass the above options in the 'opt' argument.  You MUST only use the
*                 upper 8 bits of 'opt' because the lower bits are reserved by uC/OS-II.  If you make
*                 changes to the code below, you will need to ensure that it doesn't affect the behaviour
*                 of OSTaskIdle() and OSTaskStat().
*              5) Registers are initialized to make them easy to differentiate with a debugger.
*********************************************************************************************************
*/

void *OSTaskStkInit (void (*task)(void *pd), void *pdata, void *ptos, INT16U opt)
{
    INT16U *wstk;
    INT8U  *bstk;


    opt     = opt;                     /* 'opt' is not used, prevent warning                           */
    wstk    = (INT16U *)ptos;          /* Load stack pointer                                           */
    *--wstk = (INT16U)pdata;           /* Simulate call to function with argument                      */
    *--wstk = (INT16U)task;
    *--wstk = (INT16U)task;            /* Put pointer to task   on top of stack                        */
    *--wstk = (INT16U)0x0000;          /* Y Register                                                   */
    *--wstk = (INT16U)0x0000;          /* X Register                                                   */
    *--wstk = (INT16U)0x0000;          /* D Register                                                   */
    bstk    = (INT8U *)wstk;           /* Convert WORD ptr to BYTE ptr to set CCR                      */
    *--bstk = 0xc0;                   /* CCR Register (Disable STOP instruction)                      */
    return ((void *)bstk);             /* Return pointer to new top-of-stack                           */
}

/*$PAGE*/
#if OS_CPU_HOOKS_EN
/*
*********************************************************************************************************
*                                          TASK CREATION HOOK
*
* Description: This function is called when a task is created.
*
* Arguments  : ptcb   is a pointer to the task control block of the task being created.
*
* Note(s)    : 1) Interrupts are disabled during this call.
*********************************************************************************************************
*/
void OSTaskCreateHook (OS_TCB *ptcb)
{
    ptcb = ptcb;                       /* Prevent compiler warning                                     */
}


/*
*********************************************************************************************************
*                                           TASK DELETION HOOK
*
* Description: This function is called when a task is deleted.
*
* Arguments  : ptcb   is a pointer to the task control block of the task being deleted.
*
* Note(s)    : 1) Interrupts are disabled during this call.
*********************************************************************************************************
*/

void OSTaskDelHook (OS_TCB *ptcb)
{
    ptcb = ptcb;                       /* Prevent compiler warning                                     */
}


/*
*********************************************************************************************************
*                                           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).
*********************************************************************************************************
*/

void OSTaskSwHook (void)
{
}

/*
*********************************************************************************************************
*                                           STATISTIC TASK HOOK
*
* Description: This function is called every second by uC/OS-II's statistics task.  This allows your 
*              application to add functionality to the statistics task.
*
* Arguments  : none
*********************************************************************************************************
*/

void OSTaskStatHook (void)
{

}

/*
*********************************************************************************************************
*                                               TICK HOOK
*
* Description: This function is called every tick.
*
* Arguments  : none
*
* Note(s)    : 1) Interrupts may or may not be ENABLED during this call.
*********************************************************************************************************
*/

void OSTimeTickHook (void)
{
}

#endif

#if OS_VERSION >= 251
void OSTCBInitHook (OS_TCB *ptcb)
{
    ptcb = ptcb;                                           /* Prevent Compiler warning                 */
}
#endif

#if OS_VERSION >= 251
void OSInitHookBegin (void)
{
}
#endif


#if OS_VERSION >= 251
void OSTaskIdleHook (void)
{
	
}

#endif


#if OS_VERSION >= 251
void OSInitHookEnd (void)
{
}
#endif