os_cpu_c.c

我移植的uCos 2.86 版本,可以在单片51上运行,在AT89C51ED2上测试过.

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                               (c) Copyright 2006, Micrium, Weston, FL
*                                          All Rights Reserved
*
*
*                                          dsPIC33 MPLab Port
*
*
* File         : OS_CPU_C.C
* By           : Eric Shufro
* Port Version : V2.81 (and higher)
*********************************************************************************************************
*/

#include  "..\..\..\Source\uCOS_II.H"
#include  "..\..\..\..\BSP\BSP.H"
/*
*********************************************************************************************************
*                                             LOCALS
*********************************************************************************************************
*/

#if OS_TMR_EN > 0
static  INT16U  OSTmrCtr;
#endif

/*
*********************************************************************************************************
*                                       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_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void  OSInitHookBegin (void) KCREENTRANT
{
#if OS_TMR_EN > 0
    OSTmrCtr =      0;
#endif

//    SPLIM    = 0xFFFE;                                                  /* Initialize the stack pointer limit register to a maximum */
}                                                                       /* address thus effectively disabling stack checking        */
#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_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void  OSInitHookEnd (void) KCREENTRANT
{

}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                          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.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0
void  OSTaskCreateHook (OS_TCB *ptcb) KCREENTRANT
{
#if OS_APP_HOOKS_EN > 0
    //App_TaskCreateHook(ptcb);
#else
    (void)ptcb;                                                         /* Prevent compiler warning                                 */
#endif
}
#endif

/*
*********************************************************************************************************
*                                           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.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0
void  OSTaskDelHook (OS_TCB *ptcb) KCREENTRANT
{
#if OS_APP_HOOKS_EN > 0
    //App_TaskDelHook(ptcb);
#else
    (void)ptcb;                                                         /* Prevent compiler warning                                 */
#endif
}
#endif

/*
*********************************************************************************************************
*                                             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_CPU_HOOKS_EN > 0 && OS_VERSION >= 251
void  OSTaskIdleHook (void) KCREENTRANT
{
#if OS_APP_HOOKS_EN > 0
// App_TaskIdleHook();
   	PCON = PCON | 0x01;
#endif
}
#endif

/*
*********************************************************************************************************
*                                           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
*********************************************************************************************************
*/

#if OS_CPU_HOOKS_EN > 0
void  OSTaskStatHook (void) 
{
#if OS_APP_HOOKS_EN > 0
    //App_TaskStatHook();
#endif
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                           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).
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0
void  OSTaskSwHook (void) KCREENTRANT
{
#if OS_APP_HOOKS_EN > 0
    //App_TaskSwHook();
#endif
}
#endif

/*
*********************************************************************************************************
*                                           OSTCBInit() HOOK
*
* Description: This function is called by OS_TCBInit() 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_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void  OSTCBInitHook (OS_TCB *ptcb) KCREENTRANT
{
#if OS_APP_HOOKS_EN > 0
    //App_TCBInitHook(ptcb);
#else
    (void)ptcb;                                                         /* Prevent compiler warning                                 */
#endif
}
#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.
*********************************************************************************************************
*/
#if (OS_CPU_HOOKS_EN > 0) && (OS_TIME_TICK_HOOK_EN > 0)
void  OSTimeTickHook (void) KCREENTRANT
{
#if OS_APP_HOOKS_EN > 0
    /*App_TimeTickHook();*/
#endif

#if OS_TMR_EN > 0
    OSTmrCtr++;
    if (OSTmrCtr >= (OS_TICKS_PER_SEC / OS_TMR_CFG_TICKS_PER_SEC)) {
        OSTmrCtr = 0;
        OSTmrSignal();
    }
#endif
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                        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  (vd)   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!
*********************************************************************************************************
*/

extern INT8U IDAT HW_STAKE[1];
//extern INT8U IDAT *C_IBP; 
INT8U XDAT * RDAT Ext_Stack_Top;
/*
因为void Task(void *p_arg) ; 从外部函数来调用它的时候,系统会先压入当前的PC值,
及相关的传递参数*p_arg,然后Task -> PC,正在这时,系统发生了一次中断,
系统会把PC 压入(硬件栈),然后压入一系列的其它寄存器,调用中断,
OSTaskStkInit 模拟现在是在中断中,要把这一现像保存起来
然后函数返回栈顶指针
所有函数必须是可重入的,因为重入又函数的参数传递是通过软件栈的,
而非重入的是通过全局变量来传递的,所以得不到保护
*/