test.c

ucos flashlite,从中可以学到很我flash的优化技巧.

*********************************************************************************************************
*                                             CREATE TASKS
*********************************************************************************************************
*/

static  void  TestCreateTasks (void)
{
    INT8U  err;
	INT8U  prio;
    INT8U  i;


    for (i = 0; i < TEST_N_TASKS; i++) {
        TestTaskData[i] = '0' + i;                         /* Each task will display its own letter    */
        prio            = i + 1;
        OSTaskCreateExt(TestTask, 
                    (void *)&TestTaskData[i], 
                    &TestTaskStk[i][TEST_TASK_STK_SIZE - 1], 
                    prio,
                    prio,
                    &TestTaskStk[i][0],
					TEST_TASK_STK_SIZE,
                    (void *)0,
                    OS_TASK_OPT_STK_CLR + OS_TASK_OPT_STK_CHK);
    }
}

/*
*********************************************************************************************************
*                                               TASK #1
*********************************************************************************************************
*/
static  void  TestTask (void *p_arg)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif
    INT8U      x;
    INT8U      y;
    INT8U      err;
	INT16U     i;

        

    p_arg = p_arg;                               /* Prevent compiler warning                           */
    while (TRUE) {
        OSSemPend(TestRandomSem, 0, &err);       /* Acquire semaphore to perform random numbers        */
        for (i = 0; i < TestLoops; i++) {
            x = random(80);                      /* Waste time by getting a random number              */
            y = random(10);
	    }
        x = x;                                   /* Prevent compiler warning                           */
        y = y;
        OSSemPost(TestRandomSem);                /* Release semaphore                                  */
                                                 /* Display the task number on the screen              */
        OSTimeDly(TestDly);
    }
}

/*
*********************************************************************************************************
*                                        CHECK AND GET KEYBOARD KEY
*
* Description: This function checks to see if a key has been pressed at the keyboard and returns TRUE if
*              so.  Also, if a key is pressed, the key is read and copied where the argument is pointing
*              to.
*
* Arguments  : c     is a pointer to where the read key will be stored.
*
* Returns    : TRUE  if a key was pressed
*              FALSE otherwise
*********************************************************************************************************
*/
BOOLEAN PC_GetKey (INT16S *c)
{
    if (kbhit()) {                                         /* See if a key has been pressed            */
        *c = (INT16S)getch();                              /* Get key pressed                          */
        return (TRUE);
    } else {
        *c = 0x00;                                         /* No key pressed                           */
        return (FALSE);
    }
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                             RETURN TO DOS
*
* Description : This functions returns control back to DOS by doing a 'long jump' back to the saved
*               location stored in 'PC_JumpBuf'.  The saved location was established by the function
*               'PC_DOSSaveReturn()'.  After execution of the long jump, execution will resume at the 
*               line following the 'set jump' back in 'PC_DOSSaveReturn()'.  Setting the flag 
*               'PC_ExitFlag' to TRUE ensures that the 'if' statement in 'PC_DOSSaveReturn()' executes.
*
* Arguments   : None
*
* Returns     : None
*********************************************************************************************************
*/
void PC_DOSReturn (void)
{
    PC_ExitFlag = TRUE;                                    /* Indicate we are returning to DOS         */
    longjmp(PC_JumpBuf, 1);                                /* Jump back to saved environment           */
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                        SAVE DOS RETURN LOCATION
*
* Description : This function saves the location of where we are in DOS so that it can be recovered.
*               This allows us to abort multitasking under uC/OS-II and return back to DOS as if we had
*               never left.  When this function is called by 'main()', it sets 'PC_ExitFlag' to FALSE
*               so that we don't take the 'if' branch.  Instead, the CPU registers are saved in the
*               long jump buffer 'PC_JumpBuf' and we simply return to the caller.  If a 'long jump' is
*               performed using the jump buffer then, execution would resume at the 'if' statement and
*               this time, if 'PC_ExitFlag' is set to TRUE then we would execute the 'if' statements and
*               restore the DOS environment.
*
* Arguments   : None
*
* Returns     : None
*********************************************************************************************************
*/
void PC_DOSSaveReturn (void)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    


    PC_ExitFlag  = FALSE;                                  /* Indicate that we are not exiting yet!    */
    OSTickDOSCtr =     1;                                  /* Initialize the DOS tick counter          */
    PC_TickISR   = PC_VectGet(VECT_TICK);                  /* Get MS-DOS's tick vector                 */
    
    PC_VectSet(VECT_DOS_CHAIN, PC_TickISR);                /* Store MS-DOS's tick to chain             */
    
    setjmp(PC_JumpBuf);                                    /* Capture where we are in DOS              */
    if (PC_ExitFlag == TRUE) {                             /* See if we are exiting back to DOS        */
        PC_VectSet(VECT_TICK, PC_TickISR);                 /* Restore DOS's tick vector                */
        exit(0);                                           /* Return to DOS                            */
    }
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                        OBTAIN INTERRUPT VECTOR
*
* Description: This function reads the pointer stored at the specified vector.
*
* Arguments  : vect  is the desired interrupt vector number, a number between 0 and 255.
*
* Returns    : The address of the Interrupt handler stored at the desired vector location.
*********************************************************************************************************
*/
void *PC_VectGet (INT8U vect)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    INT16U    *pvect;
    INT16U     off;
    INT16U     seg;
    
    
    pvect = (INT16U *)MK_FP(0x0000, vect * 4);        /* Point into IVT at desired vector location     */
    OS_ENTER_CRITICAL();
    off   = *pvect++;                                 /* Obtain the vector's OFFSET                    */
    seg   = *pvect;                                   /* Obtain the vector's SEGMENT                   */
    OS_EXIT_CRITICAL();
    return (MK_FP(seg, off));
}

/*
*********************************************************************************************************
*                                        INSTALL INTERRUPT VECTOR
*
* Description: This function sets an interrupt vector in the interrupt vector table.
*
* Arguments  : vect  is the desired interrupt vector number, a number between 0 and 255.
*              isr   is a pointer to a function to execute when the interrupt or exception occurs.
*
* Returns    : none
*********************************************************************************************************
*/
void PC_VectSet (INT8U vect, void (*isr)(void))
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif    
    INT16U    *pvect;
    
    
    pvect    = (INT16U *)MK_FP(0x0000, vect * 4);     /* Point into IVT at desired vector location     */
    OS_ENTER_CRITICAL();
    *pvect++ = (INT16U)FP_OFF(isr);                   /* Store ISR offset                              */
    *pvect   = (INT16U)FP_SEG(isr);                   /* Store ISR segment                             */
    OS_EXIT_CRITICAL();
}