os_cpu_c.rar_FREESCALE OS_freescale 底层

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