os_cpu_c.c

这个是ucos II 2.52在80系列上应用的部分原代码,已经证实好用

/*
**********************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                        (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
*                                          All Rights Reserved
*
*
*                                       Mitsubishi 7700 Family Specific code
*                                          
*
* File : OS_CPU_C.C
* By   : Jean J. Labrosse
* Ported by: Zhu Yifan
***********************************************************************************************
*/

#define  OS_CPU_GLOBALS

#ifndef  OS_MASTER_FILE
#include "includes.h"
#endif



/*
***********************************************************************************************
*                                        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, void *ptos, INT16U opt)
{
	INT8U * stk8;
	INT16U * stk16;
	INT32U far **stk32;

        stk8=(INT8U *)ptos;					/* Load stack pointer   */
		
    
	stk8--;
	stk8--;
	stk8--;
	stk8--;	
	stk32=(INT32U far **)stk8;
	*stk32=(INT32U far *)task;				/* push the address of task(32-bit) into stack,the upper 24-bit is PG,PCH,PCL */

	stk8--;
	*stk8=0x00;
	stk8--;
	*stk8=0x04;						/* push PSH,PSL (16-bit) into stack */

	stk8--;
	stk8--;
	stk16=(INT16U *)stk8;
	*stk16=(INT16U)pdata;					/* push A(=pdata) into stack,because the compiler will auto save the pdata parameter into A */

	stk8--;
	stk8--;
	stk16=(INT16U *)stk8;
	*stk16=0xBBBB;						/* push register B into stack */

	stk8--;
	stk8--;
	stk16=(INT16U *)stk8;
	*stk16=0xCCCC;						/* push register x into stack */						

	stk8--;
	stk8--;
	stk16=(INT16U *)stk8;
	*stk16=0xDDDD;						/* push register Y into stack */

	stk8--;
	stk8--;
	stk16=(INT16U *)stk8;
	*stk16=0x0000;						/* push register DPR into stack */

	stk8--;
	*stk8=0x00;						/* push register DT into stack */

	stk8--;
    return ((void *)stk8);
}





/*$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)
{
   
}


/*
***********************************************************************************************
*                                           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)
{
   
}

/*
***********************************************************************************************
*                                           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)
{
}

void OSIntTaskSwHook (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.
***********************************************************************************************
*/