www.pudn.com > F2812-UCOS.rar > OS_CPU_C.C
/*
*********************************************************************************************************
* 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