/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                        (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
*                                          All Rights Reserved
*
*
*                                       80x86/80x88 Specific code
*                                          LARGE MEMORY MODEL
*
* File : OS_CPU_C.C
* By   : Jean J. Labrosse
*********************************************************************************************************
*/

#define  OS_CPU_GLOBALS
#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)    : 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)
{
    INT16U *stk;
	INT16U temp;
	

    opt    = opt;                           /* 'opt' is not used, prevent warning                      */
    stk    = (INT16U *)ptos;                /* Load stack pointer                                      */
        
    *stk++ = (INT16U)(pdata);         		/* Simulate call to function with argument                 */
    *stk++ = (INT16U)(pdata);       
    
    
    *stk++ = 0x0098;						/* ST0     = 0x1111     								   */
    *stk++ = 0x0000;					    /* T       = 0x0000   									   */	    
    
    
    *stk++ = 0x3333;						/* AL      = 0x3333										   */
	*stk++ = 0x2222;						/* AH      = 0x2222 									   */
	
	
	*stk++ = 0x5555;						/* PL      = 0x5555										   */
	*stk++ = 0x4444;						/* PH      = 0x4444										   */
	
	
	*stk++ = 0x7777;						/* AR0     = 0x7777										   */
	*stk++ = 0x6666;						/* AR1     = 0x6666										   */
	
	

	*stk++ = 0xCA4B;						/* ST1     = 0x080B 								       */	
	*stk++ = 0x0000;    					/* DP      = 0x8888										   */		
	
	*stk++ = 0xffff;						/* IER     = 0xBBBB									       */
	*stk++ = 0xAAAA;						/* DBGSTAT = 0xAAAA 									   */		
	
    temp = ((INT32U)task)&0x0000ffff;			    										
    *stk++ = (INT16U)temp;					/*  保存低16位											   */		
    
	temp = ((INT32U)task)>>16;    			/*  Save task entry										   */	
    *stk++ = (INT16U)(temp);	   			/*  保存高16位											   */	    										    
    
    
    temp = ((INT32U)task)&0x0000ffff;		/* RPCL     = 0xCCCC									   */	    										
    *stk++ = (INT16U)temp;					/*  保存低16位											   */									
	
	temp = ((INT32U)task)>>16;    			/* RPCH     = 0xCCCC									   */
    *stk++ = (INT16U)(temp);	   			/*  保存高16位											   */	    										    
    
    stk++;
    return ((void *)stk);
}

/*$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