os_cpu_c.c

《嵌入式系统-使用HCS12微控制器的设计与应用》在CodeWarrior开发环境下的源程序。

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                         (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
*                                          All Rights Reserved
*
*
*                                       80x86/80x88 Specific code
*                                          LARGE MEMORY MODEL
*
*                                          Borland C/C++ V4.51
*
* File         : OS_CPU_C.C
* By           : Jean J. Labrosse
*********************************************************************************************************
*/

#define  OS_CPU_GLOBALS
#include "includes.h"			 

/*
*********************************************************************************************************
*                                       OS INITIALIZATION HOOK
*                                            (BEGINNING)
*
* Description: This function is called by OSInit() at the beginning of OSInit().
*
* Arguments  : none
*
* Note(s)    : 1) Interrupts should be disabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void  OSInitHookBegin (void)
{
}
#endif

/*
*********************************************************************************************************
*                                       OS INITIALIZATION HOOK
*                                               (END)
*
* Description: This function is called by OSInit() at the end of OSInit().
*
* Arguments  : none
*
* Note(s)    : 1) Interrupts should be disabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void  OSInitHookEnd (void)
{
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                          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.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 
void  OSTaskCreateHook (OS_TCB *ptcb)
{
    ptcb = ptcb;                       /* Prevent compiler warning                                     */
}
#endif


/*
*********************************************************************************************************
*                                           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.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 
void  OSTaskDelHook (OS_TCB *ptcb)
{
    ptcb = ptcb;                       /* Prevent compiler warning                                     */
}
#endif

/*
*********************************************************************************************************
*                                             IDLE TASK HOOK
*
* Description: This function is called by the idle task.  This hook has been added to allow you to do  
*              such things as STOP the CPU to conserve power.
*
* Arguments  : none
*
* Note(s)    : 1) Interrupts are enabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION >= 251
void  OSTaskIdleHook (void)
{
}
#endif

/*
*********************************************************************************************************
*                                           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
*********************************************************************************************************
*/

#if OS_CPU_HOOKS_EN > 0 
void  OSTaskStatHook (void)
{
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                        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)    : Interrupts are enabled when your task starts executing. You can change this by setting the
*              PSW to 0x0002 instead.  In this case, interrupts would be disabled upon task startup.  The
*              application code would be responsible for enabling interrupts at the beginning of the task
*              code.  You will need to modify OSTaskIdle() and OSTaskStat() so that they enable 
*              interrupts.  Failure to do this will make your system crash!
*********************************************************************************************************
*/

void  *OSTaskStkInit (void (*task)(void *pd), void *pdata, OS_STK *ptos, INT16U opt)
{   
    //INT16U *stk;
    //opt    = opt;                           /* 'opt' is not used, prevent warning                      */
    //stk    = (INT16U *)ptos;                /* Load stack pointer                                      */
    //*stk-- = (INT16U)FP_SEG(pdata);         /* Simulate call to function with argument                 */
    //*stk-- = (INT16U)FP_OFF(pdata);         
    //*stk-- = (INT16U)FP_SEG(task);
    //*stk-- = (INT16U)FP_OFF(task);
    //*stk-- = (INT16U)0x0202;                /* SW = Interrupts enabled                                 */
    //*stk-- = (INT16U)FP_SEG(task);          /* Put pointer to task   on top of stack                   */
    //*stk-- = (INT16U)FP_OFF(task);
    //*stk-- = (INT16U)0xAAAA;                /* AX = 0xAAAA                                             */
    //*stk-- = (INT16U)0xCCCC;                /* CX = 0xCCCC                                             */
    //*stk-- = (INT16U)0xDDDD;                /* DX = 0xDDDD                                             */
    //*stk-- = (INT16U)0xBBBB;                /* BX = 0xBBBB                                             */
    //*stk-- = (INT16U)0x0000;                /* SP = 0x0000                                             */
    //*stk-- = (INT16U)0x1111;                /* BP = 0x1111                                             */
    //*stk-- = (INT16U)0x2222;                /* SI = 0x2222                                             */
    //*stk-- = (INT16U)0x3333;                /* DI = 0x3333                                             */
    //*stk-- = (INT16U)0x4444;                /* ES = 0x4444                                             */
    //*stk   = _DS;                           /* DS = Current value of DS                                */
    //return ((OS_STK *)stk);
        
    //改写任务堆栈初始化函数
    INT16U *stk;        
    // SCISend1((INT8U)(((INT16U)pdata)>>8));
    // SCISend1((INT8U)(pdata));