os_cpu_c.c

移植ucos-ii到arm7tdmi核

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                        (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
*                                          All Rights Reserved
*
*
*                                       80x86/80x88 Specific code
*                                          LARGE MEMORY MODEL
*
* File : OS_CPU_C.C
* By   : Jean J. Labrosse
*********************************************************************************************************
*/

#define  OS_CPU_GLOBALS
#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)    : 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!
*********************************************************************************************************
*/

void *OSTaskStkInit (void (*task)(void *pd), void *pdata, void *ptos, INT16U opt)
{
    OS_STK *stk;

    opt    = opt;                           /* 'opt' is not used, prevent warning                      	*/
    stk    = (OS_STK *)ptos;                /* Load stack pointer                                      	*/
     
    * stk  = (OS_STK)task;					/* PC 								(High address) 		   	*/
    *--stk = (OS_STK)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,the first parameter is transfered by R0				*/
    *--stk = 0x10;							/* CPSR	enable IRQ and FIQ interrupt  (Low address)		   	*/

    return ((void *)stk);					
}

/*$PAGE*/
#if OS_CPU_HOOKS_EN
/*
*********************************************************************************************************
*                                          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.
*********************************************************************************************************
*/
void OSTaskCreateHook (OS_TCB *ptcb)
{
    ptcb = ptcb;                       /* Prevent compiler warning                                     */
}


/*
*********************************************************************************************************
*                                           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.
*********************************************************************************************************
*/
void OSTaskDelHook (OS_TCB *ptcb)
{
    ptcb = ptcb;                       /* Prevent compiler warning                                     */
}

/*
*********************************************************************************************************
*                                           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).
*********************************************************************************************************
*/
void OSTaskSwHook (void)
{
}

/*
*********************************************************************************************************
*                                           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
*********************************************************************************************************
*/
void OSTaskStatHook (void)
{
}

/*
*********************************************************************************************************
*                                               TICK HOOK
*
* Description: This function is called every tick.
*
* Arguments  : none
*
* Note(s)    : 1) Interrupts may or may not be ENABLED during this call.
*********************************************************************************************************
*/
void OSTimeTickHook (void)
{
}
#endif



/*
*********************************************************************************************************
*                                               SWI C handle section
*
* Description: This function is 
*
* Arguments  : none
*
* Note(s)    : 1)this section is called when SWI happened, and 
*********************************************************************************************************
*/

void SwiSecondHandler(int swi_num,int *regs)
{
	OS_TCB 	*ptcb;
	INT32U temp;
	
	switch(swi_num)
	{
		case 0x02:
			__asm
			{
				MRS	temp,SPSR
				ORR	temp,temp,#0x80					;//disable interrupt
				MSR	SPSR_c,temp
			}break;
		
		case 0x03:
			__asm
			{
				MRS	temp,SPSR
				BIC temp,temp,#0x80
				MSR	SPSR_c,temp
			}break;
		
		case 0x80:
			__asm
			{
				MRS	temp,SPSR
				BIC	temp,temp,0x1F
				ORR	temp,temp,0x1F						;//switch to system mode
				MSR	SPSR_c,temp
			}break;
		
		case 0x81:
			__asm
			{
				MRS	temp,SPSR
				BIC	temp,temp,0x1F
				ORR	temp,temp,#0x10						;//switch to user mode
				MSR	SPSR_c,temp
			}break;
	
	
		case 0x82:
			if(regs[0]<=OS_LOWEST_PRIO)
			{
				ptcb = OSTCBPrioTbl[regs[0]];
				if(ptcb!=NULL)
				{
					ptcb -> OSTCBStkPtr[1] &= ~(1<<5);
				}
			}break;
		
		case 0x83:
			if(regs[0]<=OS_LOWEST_PRIO)
			{
				ptcb = OSTCBPrioTbl[regs[0]];
				if(ptcb!=NULL)
				{
					ptcb -> OSTCBStkPtr[1] |= (1<<5);
				}
			}break;
	
		default:
			break;
	}
}