example1.c

各种硬件平台上的us OS移植实例(arm6)

/*> example1.c <*/
/*---------------------------------------------------------------------------*/
/* This is a modified version of example1 from the uC/OS book. As
 * "armsd" does not emulate a terminal there is no screen location
 * that a task can put its ID onto. Therefore the IDs are simply
 * output as they arrive.
 *
 * $Revision: 0.1 $
 *   $Author: jsmith $
 *     $Date: 0.1 $
 *
 * Copyright (c) 1994, VLSI Technoloy Inc. All Rights Reserved.
 */
/*---------------------------------------------------------------------------*/

#include	"ucos.h" 	/* uC/OS interface */
#include	"osdefs.h"  /* uC/OS ARM interface */

/*
 * P r o t o t y p e s
 */
void	Task(void *id);
void	Timer_IRQ( void );

/* allocate memory for tasks' stacks */
#define	STACKSIZE	128		/* was 64 */
uint	Stack1[STACKSIZE];
uint	Stack2[STACKSIZE];
uint	Stack3[STACKSIZE];
/*
 * G l o b a l   V a r i a b l e s
 */
OS_EVENT	*DispSem;
IRQHandlerFn prev_hand;	/* function pointer to previous handler */

/* mailbox event control blocks */
OS_EVENT *Mbox1;
OS_EVENT *Mbox2;
OS_EVENT *Mbox3;

char	PassMsg[] = "Example 1";

/*
 * Task running at the lowest priority. 
 * Wait for a message in the first mailbox and post
 * a messages to the third mailbox.
 */
void	Task1(void *Id)
{
	char	*Msg;
	uint	err;

	for (;;) {
		/* wait for a message from the input mailbox */
		Msg = (char *)OSMboxPend(Mbox1, 0, &err);

		/* print task's id */
		SWI_WriteC(*(int *)Id);			/* print task's id */

		/* post the input message to the output mailbox */
		OSMboxPost(Mbox2, Msg);
	}
}

void	Task2(void *Id)
{
	char	*Msg;
	uint	err;

	for (;;) {
		/* wait for a message from the input mailbox */
		Msg = (char *)OSMboxPend(Mbox2, 0, &err);

		/* print task's id */
		SWI_WriteC(*(int *)Id);			/* print task's id */

		/* post the input message to the output mailbox */
		OSMboxPost(Mbox3, Msg);
	}
}


void	Task3(void *Id)
{
	char	*Msg;
	uint	err;

	for (;;) {
		/* wait for a message from the input mailbox */
		Msg = (char *)OSMboxPend(Mbox3, 0, &err);

		/* print task's id */
		SWI_WriteC(*(int *)Id);			/* print task's id */

		/* post the input message to the output mailbox */
		OSMboxPost(Mbox1, Msg);
	}
}
/*
 * m a i n
 */
int	main( void )
{
 char	Id1 = '2';
 char	Id2 = '4';
 char	Id3 = '8';

 union gp	{
			unsigned char	*b;
			unsigned int	*w;
			} p;
 
	p.b = (unsigned char *) IOBase;
	


	SWI_Write0("\nExample1 using uC/OS for PID600\n\n\0");
	
	SWI_Write0("\nDoing an OSInit()...\0");
	
	OSInit();					/* needed by uC/OS */

	SWI_Write0("\nCreating the mailboxes...\0");
	
	/* 
	 * create the first mailbox in the pipeline with a message 
	 * in it to get the first task started.
	 */
	Mbox1 = OSMboxCreate(PassMsg); 
	/*
	 * create the remaining mailboxes empty
	 */
	Mbox2 = OSMboxCreate((void *)0);
	Mbox3 = OSMboxCreate((void *)0);

	SWI_Write0("\nCreating the tasks...\0");
	
	/* 
	 * create the tasks in uC/OS and assign increasing
	 * priorities to them so that Task3 at the end of
	 * the pipeline has the highest priority.
	 */
	OSTaskCreate(Task1, (void *)&Id1, (void *)&Stack1[STACKSIZE - 1], 3);
	OSTaskCreate(Task2, (void *)&Id2, (void *)&Stack2[STACKSIZE - 1], 2);
	OSTaskCreate(Task3, (void *)&Id3, (void *)&Stack3[STACKSIZE - 1], 1); 
	SWI_Write0("\nHooking into the C-DEMON's TIMER...\0");
	
	/*
	 * Now HOOK the DEMON's TIMER to uC/OS
	 */

	*(p.b + IRQM) = 0;		/* stop the TIMER interrupt */

	/*
	 * TIMER is bit position 1 in FIQ (vecnum = FIQbitvector+bit1 = 0x20 + 1)
	 */
    if ((prev_hand = ARMInstallIRQHandler(1,Timer_IRQ)) == NULL)
     {
      SWI_Write0("\nError: Unable to install timer handler.\n") ;
     }

	*(p.b + IRQM) = TimerIT;		/* restart the TIMER interrupt */

	SWI_Write0("\nDoing an OSStart()...\0");
	
	OSStart();					/* start the game */

	/*----------------- never reached -----------------------------------------
	 *
	 * Following code is here to show how to restore the original timer vector
	 */
	 
	*(p.b + IRQM) = 0;		/* remove the TIMER interrupt */

	/*
	 * TIMER is bit position 1 in FIQ (vecnum = FIQbitvector+bit1 = 0x20 + 1)
	 */
    if (ARMInstallIRQHandler(1,prev_hand) == NULL)
     {
      SWI_Write0("\nError: Unable to reinstall handler.\n") ;
     }
	
	*(p.b + IRQM) = TimerIT;	/* restart the TIMER interrupt */
}
/******************************************************************************
 *
 * T i m e r _ I R Q
 *
 * ENTER:	void
 * EXIT:	void
 *
 * Timer interrupt routine
 */
void	Timer_IRQ( void )
{
	OSTimeTick();		/* do uC/OS tick routine */
}

/*---------------------------------------------------------------------------*/
/*> EOF example1.c <*/