📄 os_cpu_c.c
字号:
/*
*********************************************************************************************************
* 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)
{
OS_STK *stk,*prestk;
opt = opt; /* 'opt' is not used, prevent warning */
stk = (OS_STK *) ptos; /* Load stack pointer */
prestk = stk;
stk++;
stk++;
//stk++; /* next word for use. Task assembly code
// will pop return address to here. */
*stk++ = (OS_STK) 0x0091; /* ST0 */
*stk++ = (OS_STK) 0x001F; /* T */
/* */
*stk++ = (OS_STK) 0x0000; /* AL */
*stk++ = (OS_STK) 0x0000; /* AH */
*stk++ = (OS_STK) 0x86A0; /* PL */
*stk++ = (OS_STK) 0x0001; // PH
*stk++ = (OS_STK) 0x0000; // AR0
*stk++ = (OS_STK) 0x0000; // AR1
*stk++ = (OS_STK) 0x8A08; // ST1
*stk++ = (OS_STK) 0x0000; // DP
*stk++ = (OS_STK) 0x0107; // IER
*stk++ = (OS_STK) 0x0000; /* */
//*stk++ = (OS_STK) (task&0xFFFF);
//*stk++ = (OS_STK) (task>>16);
/* Product Low is 0. */
*((INT32U *)stk)=(INT32U)task;
stk=stk+2;
stk++;
stk++;
*stk++ = (OS_STK) 0x0000; /* */
*stk++ = (OS_STK) 0x0000;
*stk++ = (OS_STK) 0x0000; /* */
*stk++ = (OS_STK) 0x0000;
*stk++ = (OS_STK) 0x0000; /* */
*stk++ = (OS_STK) 0x0000;
//*stk++ = (OS_STK) (pdata&0xFFFF); /* AR4 = 0 */
//*stk++ = (OS_STK) (pdata>>16);
*((INT32U *)stk)=(INT32U)pdata;
stk=stk+2;
*stk++ = (OS_STK) 0x0000; /* */
*stk++ = (OS_STK) 0x0000;
*stk++ = (OS_STK) 0x0000; /* */
*stk++ = (OS_STK) 0x0000;
*stk++ = (OS_STK) 0x0000; /* */
*stk++ = (OS_STK) 0x0000;
*stk++ = (OS_STK) 0x0000; /* */
*stk++ = (OS_STK) 0x0000;
*stk++ = (OS_STK) 0x0000; /* */
*stk++ = (OS_STK) 0x0000;
*stk++ = (OS_STK) 0x0010;
*stk++ = (OS_STK) 0x0000;
if(stk<(OS_STK *)0x400)
return ((void *)stk);
else
return ((void *)(stk-prestk+0x400));
}
/*$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
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -