os_cpu_c.c

这个UCOS II在TI2400DSP平台上的移植源代码

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                         (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
*                                          All Rights Reserved
*
*
*                                  TI's TMS320C2400 Series Specific Code
*                
*
*                           	Code Generation Toolset Release Version 7.00
*
*
* File         : OS_CPU_C.C
* By           : Jean J. Labrosse 		(Modified by Ding Curie)
*********************************************************************************************************
*/
#include "includes.h"

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

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

/*
*********************************************************************************************************
*                                        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)    : (by Ding Curie)  
*			   1) Context saving is performed by I$$SAVE, which is a run-time-support function and is
*			      automatically called by the C compiler immediately after an interrupt is vectored,
*				  that is, before the SP is adjusted to build the local frame, if you write your ISRs
*				  in C with the keyword 'interrupt'.
*			   2) When a task is interrupted, the stack looks like this: 
*
*					BLANK ENTRY			<-- SP, before saving the context
*					ST1
*					ST0
*					ACCH
*					ACCL
*				|	PH
*				|	PL
*				|	T
*				|	AR0
*				|	AR2
*				V	AR3
*					AR4
*					AR5
*					AR6
*					AR7
*					HW STACK LEVEL 2	; The Interrupt Return Address
*					HW STACK LEVEL 3	
*					HW STACK LEVEL 4
*					HW STACK LEVEL 5
*					HW STACK LEVEL 6
*					HW STACK LEVEL 7
*					HW STACK LEVEL 8
*					BLANK ENTRY			<-- SP, after saving the context
*
*			   3) Notice that HW STACK LEVEL 1 is consumed by the call to I$$SAVE, and then POPed out 
*				  before saving the remainder 7 entries.
*			   4) Upon return from an ISR, context is restored by calling I$$REST, the counterpart of 
*			      I$$SAVE. 
*********************************************************************************************************
*/

OS_STK *OSTaskStkInit(void (*task)(void *pd), 
					  void *pdata, 
					  OS_STK *ptos, 
					  INT16U opt)
{
	opt = opt;
	*ptos++ = (OS_STK)pdata;	/* augument 		*/
	*ptos++ = (OS_STK)0;		/* blank            */
	*ptos++ = (OS_STK)0x27FC;	/* ST1              */
	*ptos++ = (OS_STK)0x2600;	/* ST0              */
	*ptos++ = (OS_STK)0;		/* ACCH             */
	*ptos++ = (OS_STK)0;		/* ACCL             */
	*ptos++ = (OS_STK)0;		/* PH               */
	*ptos++ = (OS_STK)0;		/* PL               */
	*ptos++ = (OS_STK)0;		/* T                */
	*ptos++ = (OS_STK)0;		/* AR0              */
	*ptos++ = (OS_STK)0;		/* AR2              */
	*ptos++ = (OS_STK)0;		/* AR3              */
	*ptos++ = (OS_STK)0;		/* AR4              */
	*ptos++ = (OS_STK)0;		/* AR5              */
	*ptos++ = (OS_STK)0;		/* AR6              */
	*ptos++ = (OS_STK)0;		/* AR7              */
	*ptos++ = (OS_STK)task;		/* HW STACK LEVEL 2 */
	*ptos++ = (OS_STK)0;		/* HW STACK LEVEL 3 */
	*ptos++ = (OS_STK)0;		/* HW STACK LEVEL 4 */
	*ptos++ = (OS_STK)0;		/* HW STACK LEVEL 5 */
	*ptos++ = (OS_STK)0;		/* HW STACK LEVEL 6 */
	*ptos++ = (OS_STK)0;		/* HW STACK LEVEL 7 */
	*ptos++ = (OS_STK)0;		/* HW STACK LEVEL 8	*/				
	
	return ptos;
}

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