eg1.c

ucos源码

/*
 * File:        example1.c
 *
 * uC/OS Real-time multitasking kernel for the ARM processor.
 *
 * Simple example of using multiple tasks and mailboxes.
 *
 * Created by Marco Graziano ([e-mail]).
 *
 */

#include	"includes.h"               /* uC/OS interface */
//#include    "Sems.h"
/* allocate memory for tasks' stacks */
#ifdef SEMIHOSTED
#define	STACKSIZE	(64+SEMIHOSTED_STACK_NEEDS)
#else
#define	STACKSIZE	256
#endif
OS_STK Stack1[STACKSIZE]= {0, };
OS_STK Stack2[STACKSIZE]= {0, };
OS_STK Stack3[STACKSIZE]= {0, };

OS_EVENT *UART_sem;
/* 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;
    INT8U err;
	OSSemPend(UART_sem, 0, &err);
    uHALr_printf("Task1() called\r\n");

    for (;;)
    {

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

        /* print task's id */
        uHALr_printf("%c", *(char *)Id);

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

void
 Task2(void *Id)
{
    char *Msg;
    INT8U err;

    uHALr_printf("Task2() called\r\n");

    for (;;)
    {

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

        /* print task's id */
        uHALr_printf("%c", *(char *)Id);


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


void
 Task3(void *Id)
{
    char *Msg;
    INT8U err;

    uHALr_printf("Task3() called\r\n");


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

        /* print task's id */
        uHALr_printf("%c", *(char *)Id);

        /* post the input message to the output mailbox */
        OSMboxPost(Mbox1, Msg);
    }
}


/*
 * Main function.
 */
int
 Main(int argc, char **argv)
{
    char Id1 = '1';
    char Id2 = '2';
    char Id3 = '3';



    /* do target (uHAL based ARM system) initialisation */
	ARMTargetInit();

    /* needed by uC/OS */
	OSInit();

	uHALr_ResetMMU();

    /* 
     * 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);

    /* 
     * 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, (OS_STK *)&Stack1[STACKSIZE - 1], 3);
	OSTaskCreate(Task2, (void *)&Id2, (OS_STK *)&Stack2[STACKSIZE - 1], 2);
	OSTaskCreate(Task3, (void *)&Id3, (OS_STK *)&Stack3[STACKSIZE - 1], 1);

    /* Start the (uHAL based ARM system) system running */
    ARMTargetStart();

    /* start the game */
    OSStart();

    /* never reached */
	return 0;
}                               /* main */