?? os_cpu_c.c
字號:
/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
*
* (c) Copyright 1992-2001, 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
*********************************************************************************************************
*/
#include "includes.h"
#include <string.h>
#define OS_CPU_GLOBALS
#define FP_OFF(fp)((unsigned)(fp))
#define FP_SEG(fp)((unsigned)((unsigned long)(fp) >> 16))
/*
*********************************************************************************************************
* 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 TaskBucket()
{
while (1)
;
}
OS_STK *OSTaskStkInit (void (*task)(void *pd), void *pdata, OS_STK *ptos, INT16U opt)
{
#if 0
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);
#endif
OS_STK* stk;
stk = (OS_STK *) ptos; // Load stack pointer
*--stk = (INT32U) pdata; // Simulate a function call (to pass the parameter)
*--stk = (INT32U) TaskBucket; // Return address in case the task exits.
*--stk = 0x00000202; // Eflags (interrupt flag enabled)
*--stk = 0x18; // CS: define in TA
*--stk = (INT32U) task; // Entry point
*--stk = 0; // EAX
*--stk = 0; // ECX
*--stk = 0; // EDX
*--stk = 0; // EBX
*--stk = 0; // ESP (unused)
*--stk = 0; // EBP
*--stk = 0; // ESI
*--stk = 0; // EDI
return stk;
}
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZE A TASK'S STACK FOR FLOATING POINT EMULATION
*
* Description: This function MUST be called BEFORE calling either OSTaskCreate() or OSTaskCreateExt() in
* order to initialize the task's stack to allow the task to use the Borland floating-point
* emulation. The returned pointer MUST be used in the task creation call.
*
* Ex.: OS_STK TaskStk[1000];
*
*
* void main (void)
* {
* OS_STK *ptos;
* OS_STK *pbos;
* INT32U size;
*
*
* OSInit();
* .
* .
* ptos = &TaskStk[999];
* pbos = &TaskStk[0];
* psize = 1000;
* OSTaskStkInit_FPE_x86(&ptos, &pbos, &size);
* OSTaskCreate(Task, (void *)0, ptos, 10);
* .
* .
* OSStart();
* }
*
* Arguments : pptos is the pointer to the task's top-of-stack pointer which would be passed to
* OSTaskCreate() or OSTaskCreateExt().
*
* ppbos is the pointer to the new bottom of stack pointer which would be passed to
* OSTaskCreateExt().
*
* psize is a pointer to the size of the stack (in number of stack elements). You
* MUST allocate sufficient stack space to leave at least 384 bytes for the
* floating-point emulation.
*
* Returns : The new size of the stack once memory is allocated to the floating-point emulation.
*
* Note(s) : 1) _SS is a Borland 'pseudoregister' and returns the contents of the Stack Segment (SS)
* 2) The pointer to the top-of-stack (pptos) will be modified so that it points to the new
* top-of-stack.
* 3) The pointer to the bottom-of-stack (ppbos) will be modified so that it points to the new
* bottom-of-stack.
* 4) The new size of the stack is adjusted to reflect the fact that memory was reserved on
* the stack for the floating-point emulation.
*********************************************************************************************************
*/
/*$PAGE*/
#if OS_CPU_HOOKS_EN
/*
*********************************************************************************************************
* 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_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_VERSION > 203
void OSInitHookEnd (void)
{
}
#endif
/*
*********************************************************************************************************
* 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)
{
}
/*
*********************************************************************************************************
* OSTCBInit() HOOK
*
* Description: This function is called by OSTCBInit() after setting up most of the TCB.
*
* Arguments : ptcb is a pointer to the TCB of the task being created.
*
* Note(s) : 1) Interrupts may or may not be ENABLED during this call.
*********************************************************************************************************
*/
#if OS_VERSION > 203
void OSTCBInitHook (OS_TCB *ptcb)
{
ptcb = ptcb; /* Prevent Compiler warning */
}
#endif
/*
*********************************************************************************************************
* 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)
{
}
/*
*********************************************************************************************************
* 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_VERSION >= 251
void OSTaskIdleHook (void)
{
}
#endif
#endif
?? 快捷鍵說明
復(fù)制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -