www.pudn.com > uCOSII_no.rar > OS_CPU_C.C, change:2005-05-14,size:10055b


/* 
********************************************************************************************************* 
*                                               uC/OS-II 
*                                         The Real-Time Kernel 
* 
*                        (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL 
*                                          All Rights Reserved 
*                        (c) Copyright ARM Limited 1999.  All rights reserved. 
* 
*                                          ARM Specific code 
* 
* 
* File : OS_CPU_C.C 
********************************************************************************************************* 
*/ 
 
#define  OS_CPU_GLOBALS 
#include "ucos_ii.h" 
 
 
#define BUILD_DATE "Build Date: " __DATE__ "\n" 
 
/* 
********************************************************************************************************* 
*                                        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! 
********************************************************************************************************* 
*/ 
 
OS_STK *OSTaskStkInit(void (*task)(void *pd), void *pdata, OS_STK *ptos, INT16U opt) 
{ 
    OS_STK *stk; 
 
    opt    = opt;                           /* 'opt' is not used, prevent warning                      */ 
    stk    = (unsigned int *)ptos;          /* Load stack pointer                                      */ 
 
    /* build a context for the new task */ 
    *--stk = (unsigned int) task;       /* pc */ 
    *--stk = (unsigned int) task;       /* lr */ 
 
    *--stk = 0;                         /* r12 */ 
    *--stk = 0;                         /* r11 */ 
    *--stk = 0;                         /* r10 */ 
    *--stk = 0;                         /* r9 */ 
    *--stk = 0;                         /* r8 */ 
    *--stk = 0;                         /* r7 */ 
    *--stk = 0;                         /* r6 */ 
    *--stk = 0;                         /* r5 */ 
    *--stk = 0;                         /* r4 */ 
    *--stk = 0;                         /* r3 */ 
    *--stk = 0;                         /* r2 */ 
    *--stk = 0;                         /* r1 */ 
    *--stk = (unsigned int) pdata;      /* r0 */ 
    *--stk = (SVC32MODE|0x0);	    /* cpsr  IRQ, FIQ disable */ 
//    *--stk = (SVC32MODE|0x0);	    /* spsr  IRQ, FIQ disable */ 
 
 
    return (stk); 
} 
 
/*$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) 
{ 
} 
#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