?? os_cpu_c.c
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/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
*
* (c) Copyright 1992-2003, Jean J. Labrosse, Weston, FL
* All Rights Reserved
* MC9S12DP256 Specific code
* (MetroWerks C/C++ V4.2)
*
*
* File : OS_CPU_C.C
* By : Jean J. Labrosse
* Ported to MC9S12DP256 by Abderrahmane Assal
*********************************************************************************************************
*/
#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) : 1) XIRQ interrupts are disabled when your task starts executing. You can change this by
* clearing BIT6 in the CCR.
* 2) The STOP instruction is disabled when your task starts executing. You can change this
* by clearing BIT7 in the CCR.
* 3) The other interrupts (i.e. maskable interrupts) are enabled when your task starts
* executing. You can change this by setting BIT4 in the CCR.
* 4) You can change pass the above options in the 'opt' argument. You MUST only use the
* upper 8 bits of 'opt' because the lower bits are reserved by uC/OS-II. If you make
* changes to the code below, you will need to ensure that it doesn't affect the behaviour
* of OSTaskIdle() and OSTaskStat().
* 5) Registers are initialized to make them easy to differentiate with a debugger.
* 6) Tasks do not have to be in NON-PAGED memory.That is why I added an extra byte in every task's
* stack to save the PPAGE register that locate the memory page where the task is located. If a
* context switch occurs, the proper page will be saved/restored by uC/OS-II. This done automatically
* by the hardware provided that we add the option -CpPPAGE=0x30 as a compiler argument.
*
**********************************************************************************************************************
*/
void *OSTaskStkInit (void (*task)(void *pd), void *pdata, void *ptos, INT16U opt)
{
INT16U *wstk;
INT8U *bstk;
INT8U regPage; /* regPage is used to save the PAGE register */
INT16U *OffsetAddress;
opt = opt; /* 'opt' is not used, prevent warning */
wstk = (INT16U *)ptos; /* Load stack pointer */
*--wstk = (INT16U)pdata; /* Simulate call to function with argument */
OffsetAddress = (INT16U*)&task;
regPage = (INT8U)task;
*--wstk = (INT16U)*OffsetAddress;
*--wstk = (INT16U)*OffsetAddress; /* Put pointer to task on top of stack */
*--wstk = (INT16U)0x2222; /* Y Register */
*--wstk = (INT16U)0x1111; /* X Register */
*--wstk = (INT16U)0xBBAA; /* D Register */
bstk = (INT8U *)wstk; /* Convert WORD ptr to BYTE ptr to set CCR */
*--bstk = 0x80; /* CCR Register (Disable STOP instruction) */
#if defined( __BANKED__) || defined(__LARGE__)
*--bstk = regPage; /* Save the PPAGE register in case of banked memory model (see note 6) */
#endif
return ((void *)bstk); /* Return pointer to new top-of-stack */
}
/*$PAGE*/
/*
*********************************************************************************************************
* OS INITIALIZATION HOOK
* (BEGINNING)
*
* Description: This function is called by OSInit() at the beginning of OSInit().
*
* Arguments : none
*
* Note(s) : 1) Interrupts should be disabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void OSInitHookBegin (void)
{
}
#endif
/*
*********************************************************************************************************
* OS INITIALIZATION HOOK
* (END)
*
* Description: This function is called by OSInit() at the end of OSInit().
*
* Arguments : none
*
* Note(s) : 1) Interrupts should be disabled during this call.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203
void OSInitHookEnd (void)
{
}
#endif
/*$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)
{
ptcb = ptcb; /* Prevent compiler warning */
}
#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)
{
ptcb = ptcb; /* Prevent compiler warning */
}
#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)
{
//asm stop;
}
#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)
{
}
#endif
/*
*********************************************************************************************************
* 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)
{
}
#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)
{
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.
*********************************************************************************************************
*/
#if OS_CPU_HOOKS_EN > 0
void OSTimeTickHook (void)
{
}
#endif
/********************************************************************************************************
; SAVE THE CCR AND DISABLE INTERRUPTS
; &
; RESTORE CCR
;
; Description : These function implements OS_CRITICAL_METHOD #3
;
; Arguments : The function prototypes for the two functions are:
; 1) OS_CPU_SR OSCPUSaveSR(void)
; where OS_CPU_SR is the contents of the CCR register prior to disabling
; interrupts.
; 2) void OSCPURestoreSR(OS_CPU_SR os_cpu_sr);
; 'os_cpu_sr' the the value of the CCR to restore.
;
; Note(s) : 1) It's assumed that the compiler uses the B register to pass a single 8-bit argument
; to and from an assembly language function.
;********************************************************************************************************/
void OSCPUSaveSR(OS_CPU_SR os_cpu_sr)
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