/*
 * FreeRTOS V202212.00
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * https://www.FreeRTOS.org
 * https://github.com/FreeRTOS
 *
 */

/*
 * main-blinky.c is included when the "Blinky" build configuration is used.
 * main-full.c is included when the "Full" build configuration is used.
 *
 * main-full.c (this file) defines a comprehensive demo that creates many
 * tasks, queues, semaphores and timers.  It also demonstrates how Cortex-M3
 * interrupts can interact with FreeRTOS tasks/timers.
 *
 * This demo project runs on the SK-FM3-64PMC1 evaluation board, which is
 * populated with an MB9A300 microcontroller.
 *
 * The main() Function:
 * main() creates three demo specific software timers, one demo specific queue,
 * and two demo specific tasks.  It then creates a whole host of 'standard
 * demo' tasks/queues/semaphores, before starting the scheduler.  The demo
 * specific tasks and timers are described in the comments here.  The standard
 * demo tasks are described on the FreeRTOS.org web site.
 *
 * The standard demo tasks provide no specific functionality.  They are
 * included to both test the FreeRTOS port, and provide examples of how the
 * various FreeRTOS API functions can be used.
 *
 * This demo creates 43 tasks in total.  If you want a simpler demo, use the
 * Blinky build configuration.
 *
 * The Demo Specific Queue Send Task:
 * The queue send task is implemented by the prvQueueSendTask() function in
 * this file.  prvQueueSendTask() sits in a loop that causes it to repeatedly
 * block for 200 milliseconds, before sending the value 100 to the queue that
 * was created within main().  Once the value is sent, the task loops back
 * around to block for another 200 milliseconds.
 *
 * The Demo Specific Queue Receive Task:
 * The queue receive task is implemented by the prvQueueReceiveTask() function
 * in this file.  prvQueueReceiveTask() sits in a loop that causes it to
 * repeatedly attempt to read data from the queue that was created within
 * main().  When data is received, the task checks the value of the data, and
 * if the value equals the expected 100, toggles an LED in the 7 segment display
 * (see the documentation page for this demo on the FreeRTOS.org site to see
 * which LED is used).  The 'block time' parameter passed to the queue receive
 * function specifies that the task should be held in the Blocked state
 * indefinitely to wait for data to be available on the queue.  The queue
 * receive task will only leave the Blocked state when the queue send task
 * writes to the queue.  As the queue send task writes to the queue every 200
 * milliseconds, the queue receive task leaves the Blocked state every 200
 * milliseconds, and therefore toggles the LED every 200 milliseconds.
 *
 * The Demo Specific LED Software Timer and the Button Interrupt:
 * The user button SW2 is configured to generate an interrupt each time it is
 * pressed.  The interrupt service routine switches an LED on, and resets the
 * LED software timer.  The LED timer has a 5000 millisecond (5 second) period,
 * and uses a callback function that is defined to just turn the LED off again.
 * Therefore, pressing the user button will turn the LED on, and the LED will
 * remain on until a full five seconds pass without the button being pressed.
 * See the documentation page for this demo on the FreeRTOS.org web site to see
 * which LED is used.
 *
 * The Demo Specific "Check" Callback Function:
 * This is called each time the 'check' timer expires.  The check timer
 * callback function inspects all the standard demo tasks to see if they are
 * all executing as expected.  The check timer is initially configured to
 * expire every three seconds, but will shorted this to every 500ms if an error
 * is ever discovered.  The check timer callback toggles the LED defined by
 * the mainCHECK_LED definition each time it executes.  Therefore, if LED
 * mainCHECK_LED is toggling every three seconds, then no error have been found.
 * If LED mainCHECK_LED is toggling every 500ms, then at least one errors has
 * been found.  The variable pcStatusMessage is set to a string that indicates
 * which task reported an error.  See the documentation page for this demo on
 * the FreeRTOS.org web site to see which LED in the 7 segment display is used.
 *
 * The Demo Specific "Digit Counter" Callback Function:
 * This is called each time the 'digit counter' timer expires.  It causes the
 * digits 0 to 9 to be displayed in turn as the first character of the two
 * character display.  The LEDs in the other digit of the two character
 * display are used as general purpose LEDs, as described in this comment block.
 *
 * The Demo Specific Idle Hook Function:
 * The idle hook function demonstrates how to query the amount of FreeRTOS heap
 * space that is remaining (see vApplicationIdleHook() defined in this file).
 *
 * The Demo Specific Tick Hook Function:
 * The tick hook function is used to test the interrupt safe software timer
 * functionality.
 */

/* Kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "timers.h"

/* Fujitsu drivers/libraries. */
#include "mcu.h"

/* Common demo includes. */
#include "partest.h"
#include "flash.h"
#include "BlockQ.h"
#include "death.h"
#include "blocktim.h"
#include "semtest.h"
#include "GenQTest.h"
#include "QPeek.h"
#include "recmutex.h"
#include "TimerDemo.h"
#include "comtest2.h"
#include "PollQ.h"
#include "countsem.h"
#include "dynamic.h"

/* The rate at which data is sent to the queue, specified in milliseconds, and
 * converted to ticks using the portTICK_PERIOD_MS constant. */
#define mainQUEUE_SEND_FREQUENCY_MS          ( 200 / portTICK_PERIOD_MS )

/* The number of items the queue can hold.  This is 1 as the receive task
 * will remove items as they are added, meaning the send task should always find
 * the queue empty. */
#define mainQUEUE_LENGTH                     ( 1 )

/* The LED toggled by the check timer callback function.  This is an LED in the
 *  second digit of the two digit 7 segment display.  See the documentation page
 *  for this demo on the FreeRTOS.org web site to see which LED this relates to. */
#define mainCHECK_LED                        ( 1UL << 3UL )

/* The LED toggle by the queue receive task.  This is an LED in the second digit
 * of the two digit 7 segment display.  See the documentation page for this demo on
 * the FreeRTOS.org web site to see which LED this relates to. */
#define mainTASK_CONTROLLED_LED              0x07UL

/* The LED turned on by the button interrupt, and turned off by the LED timer.
 * This is an LED in the second digit of the two digit 7 segment display.  See the
 * documentation page for this demo on the FreeRTOS.org web site to see which LED
 * this relates to. */
#define mainTIMER_CONTROLLED_LED             0x05UL

/* The LED used by the comtest tasks. See the comtest.c file for more
 * information.  The LEDs used by the comtest task are in the second digit of the
 * two digit 7 segment display.  See the documentation page for this demo on the
 * FreeRTOS.org web site to see which LEDs this relates to. */
#define mainCOM_TEST_LED                     0x03UL

/* Constant used by the standard timer test functions. */
#define mainTIMER_TEST_PERIOD                ( 50 )

/* Priorities used by the various different standard demo tasks. */
#define mainCHECK_TASK_PRIORITY              ( configMAX_PRIORITIES - 1 )
#define mainQUEUE_POLL_PRIORITY              ( tskIDLE_PRIORITY + 1 )
#define mainSEM_TEST_PRIORITY                ( tskIDLE_PRIORITY + 1 )
#define mainBLOCK_Q_PRIORITY                 ( tskIDLE_PRIORITY + 2 )
#define mainCREATOR_TASK_PRIORITY            ( tskIDLE_PRIORITY + 3 )
#define mainFLASH_TASK_PRIORITY              ( tskIDLE_PRIORITY + 1 )
#define mainINTEGER_TASK_PRIORITY            ( tskIDLE_PRIORITY )
#define mainGEN_QUEUE_TASK_PRIORITY          ( tskIDLE_PRIORITY )
#define mainCOM_TEST_PRIORITY                ( tskIDLE_PRIORITY + 2 )

/* Priorities defined in this main-full.c file. */
#define mainQUEUE_RECEIVE_TASK_PRIORITY      ( tskIDLE_PRIORITY + 2 )
#define mainQUEUE_SEND_TASK_PRIORITY         ( tskIDLE_PRIORITY + 1 )

/* The period at which the check timer will expire, in ms, provided no errors
 * have been reported by any of the standard demo tasks.  ms are converted to the
 * equivalent in ticks using the portTICK_PERIOD_MS constant. */
#define mainCHECK_TIMER_PERIOD_MS            ( 3000UL / portTICK_PERIOD_MS )

/* The period at which the check timer will expire, in ms, if an error has been
 * reported in one of the standard demo tasks.  ms are converted to the equivalent
 * in ticks using the portTICK_PERIOD_MS constant. */
#define mainERROR_CHECK_TIMER_PERIOD_MS      ( 500UL / portTICK_PERIOD_MS )

/* The period at which the digit counter timer will expire, in ms, and converted
 * to ticks using the portTICK_PERIOD_MS constant. */
#define mainDIGIT_COUNTER_TIMER_PERIOD_MS    ( 250UL / portTICK_PERIOD_MS )

/* The LED will remain on until the button has not been pushed for a full
 * 5000ms. */
#define mainLED_TIMER_PERIOD_MS              ( 5000UL / portTICK_PERIOD_MS )

/* A zero block time. */
#define mainDONT_BLOCK                       ( 0UL )

/* Baud rate used by the comtest tasks. */
#define mainCOM_TEST_BAUD_RATE               ( 115200UL )

/*-----------------------------------------------------------*/

/*
 * Setup the NVIC, LED outputs, and button inputs.
 */
static void prvSetupHardware( void );

/*
 * The application specific (not common demo) tasks as described in the comments
 * at the top of this file.
 */
static void prvQueueReceiveTask( void * pvParameters );
static void prvQueueSendTask( void * pvParameters );

/*
 * The LED timer callback function.  This does nothing but switch an LED off.
 */
static void prvLEDTimerCallback( TimerHandle_t xTimer );

/*
 * The check timer callback function, as described at the top of this file.
 */
static void prvCheckTimerCallback( TimerHandle_t xTimer );

/*
 * The digit counter callback function, as described at the top of this file.
 */
static void prvDigitCounterTimerCallback( TimerHandle_t xTimer );

/*
 * This is not a 'standard' partest function, so the prototype is not in
 * partest.h, and is instead included here.
 */
void vParTestSetLEDFromISR( unsigned portBASE_TYPE uxLED,
                            signed portBASE_TYPE xValue );

/*-----------------------------------------------------------*/

/* The queue used by both application specific demo tasks defined in this file. */
static QueueHandle_t xQueue = NULL;

/* The LED software timer.  This uses prvLEDTimerCallback() as it's callback
 * function. */
static TimerHandle_t xLEDTimer = NULL;

/* The digit counter software timer.  This displays a counting digit on one half
 * of the seven segment displays. */
static TimerHandle_t xDigitCounterTimer = NULL;

/* The check timer.  This uses prvCheckTimerCallback() as its callback
 * function. */
static TimerHandle_t xCheckTimer = NULL;

/* If an error is detected in a standard demo task, then pcStatusMessage will
 * be set to point to a string that identifies the offending task.  This is just
 * to make debugging easier. */
static const char * pcStatusMessage = NULL;

/*-----------------------------------------------------------*/

int main( void )
{
    /* Configure the NVIC, LED outputs and button inputs. */
    prvSetupHardware();

    /* Create the queue. */
    xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( unsigned long ) );

    if( xQueue != NULL )
    {
        /* Start the two application specific demo tasks, as described in the
         * comments at the top of this	file. */
        xTaskCreate( prvQueueReceiveTask, "Rx", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_RECEIVE_TASK_PRIORITY, NULL );
        xTaskCreate( prvQueueSendTask, "TX", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_SEND_TASK_PRIORITY, NULL );

        /* Create the software timer that is responsible for turning off the LED
         * if the button is not pushed within 5000ms, as described at the top of
         * this file. */
        xLEDTimer = xTimerCreate( "LEDTimer",                  /* A text name, purely to help debugging. */
                                  ( mainLED_TIMER_PERIOD_MS ), /* The timer period, in this case 5000ms (5s). */
                                  pdFALSE,                     /* This is a one-shot timer, so xAutoReload is set to pdFALSE. */
                                  ( void * ) 0,                /* The ID is not used, so can be set to anything. */
                                  prvLEDTimerCallback          /* The callback function that switches the LED off. */
                                  );

        /* Create the software timer that performs the 'check' functionality,
         * as described at the top of this file. */
        xCheckTimer = xTimerCreate( "CheckTimer",                  /* A text name, purely to help debugging. */
                                    ( mainCHECK_TIMER_PERIOD_MS ), /* The timer period, in this case 3000ms (3s). */
                                    pdTRUE,                        /* This is an auto-reload timer, so xAutoReload is set to pdTRUE. */
                                    ( void * ) 0,                  /* The ID is not used, so can be set to anything. */
                                    prvCheckTimerCallback          /* The callback function that inspects the status of all the other tasks. */
                                    );

        /* Create the software timer that performs the 'digit counting'
         * functionality, as described at the top of this file. */
        xDigitCounterTimer = xTimerCreate( "DigitCounter",                        /* A text name, purely to help debugging. */
                                           ( mainDIGIT_COUNTER_TIMER_PERIOD_MS ), /* The timer period, in this case 3000ms (3s). */
                                           pdTRUE,                                /* This is an auto-reload timer, so xAutoReload is set to pdTRUE. */
                                           ( void * ) 0,                          /* The ID is not used, so can be set to anything. */
                                           prvDigitCounterTimerCallback           /* The callback function that inspects the status of all the other tasks. */
                                           );

        /* Create a lot of 'standard demo' tasks.  Over 40 tasks are created in
         * this demo.  For a much simpler demo, select the 'blinky' build
         * configuration. */
        vStartBlockingQueueTasks( mainBLOCK_Q_PRIORITY );
        vCreateBlockTimeTasks();
        vStartSemaphoreTasks( mainSEM_TEST_PRIORITY );
        vStartGenericQueueTasks( mainGEN_QUEUE_TASK_PRIORITY );
        vStartLEDFlashTasks( mainFLASH_TASK_PRIORITY );
        vStartQueuePeekTasks();
        vStartRecursiveMutexTasks();
        vStartTimerDemoTask( mainTIMER_TEST_PERIOD );
        vAltStartComTestTasks( mainCOM_TEST_PRIORITY, mainCOM_TEST_BAUD_RATE, mainCOM_TEST_LED );
        vStartPolledQueueTasks( mainQUEUE_POLL_PRIORITY );
        vStartCountingSemaphoreTasks();
        vStartDynamicPriorityTasks();

        /* The suicide tasks must be created last, as they need to know how many
         * tasks were running prior to their creation in order to ascertain whether
         * or not the correct/expected number of tasks are running at any given
         * time. */
        vCreateSuicidalTasks( mainCREATOR_TASK_PRIORITY );

        /* Start the tasks and timer running. */
        vTaskStartScheduler();
    }

    /* If all is well, the scheduler will now be running, and the following line
     * will never be reached.  If the following line does execute, then there was
     * insufficient FreeRTOS heap memory available for the idle and/or timer tasks
     * to be created.  See the memory management section on the FreeRTOS web site
     * for more details. */
    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/

static void prvCheckTimerCallback( TimerHandle_t xTimer )
{
    /* Check the standard demo tasks are running without error.   Latch the
     * latest reported error in the pcStatusMessage character pointer. */
    if( xAreGenericQueueTasksStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: GenQueue";
    }

    if( xAreQueuePeekTasksStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: QueuePeek\r\n";
    }

    if( xAreBlockingQueuesStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: BlockQueue\r\n";
    }

    if( xAreBlockTimeTestTasksStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: BlockTime\r\n";
    }

    if( xAreSemaphoreTasksStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: SemTest\r\n";
    }

    if( xIsCreateTaskStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: Death\r\n";
    }

    if( xAreRecursiveMutexTasksStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: RecMutex\r\n";
    }

    if( xAreComTestTasksStillRunning() != pdPASS )
    {
        pcStatusMessage = "Error: ComTest\r\n";
    }

    if( xAreTimerDemoTasksStillRunning( ( mainCHECK_TIMER_PERIOD_MS ) ) != pdTRUE )
    {
        pcStatusMessage = "Error: TimerDemo";
    }

    if( xArePollingQueuesStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: PollQueue";
    }

    if( xAreCountingSemaphoreTasksStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: CountSem";
    }

    if( xAreDynamicPriorityTasksStillRunning() != pdTRUE )
    {
        pcStatusMessage = "Error: DynamicPriority";
    }

    /* Toggle the check LED to give an indication of the system status.  If
     * the LED toggles every mainCHECK_TIMER_PERIOD_MS milliseconds then
     * everything is ok.  A faster toggle indicates an error.  vParTestToggleLED()
     * is not used to toggle this particular LED as it is on a different IP port
     * to to the LEDs controlled by ParTest.c.  A critical section is not required
     * as the only other place this port is accessed is from another timer - and
     * only one timer can be running at any one time. */
    if( ( FM3_GPIO->PDOR3 & mainCHECK_LED ) != 0 )
    {
        FM3_GPIO->PDOR3 &= ~mainCHECK_LED;
    }
    else
    {
        FM3_GPIO->PDOR3 |= mainCHECK_LED;
    }

    /* Have any errors been latch in pcStatusMessage?  If so, shorten the
     * period of the check timer to mainERROR_CHECK_TIMER_PERIOD_MS milliseconds.
     * This will result in an increase in the rate at which mainCHECK_LED
     * toggles. */
    if( pcStatusMessage != NULL )
    {
        /* This call to xTimerChangePeriod() uses a zero block time.  Functions
         * called from inside of a timer callback function must *never* attempt
         * to block. */
        xTimerChangePeriod( xCheckTimer, ( mainERROR_CHECK_TIMER_PERIOD_MS ), mainDONT_BLOCK );
    }
}
/*-----------------------------------------------------------*/

static void prvLEDTimerCallback( TimerHandle_t xTimer )
{
    /* The timer has expired - so no button pushes have occurred in the last
     * five seconds - turn the LED off. */
    vParTestSetLED( mainTIMER_CONTROLLED_LED, pdFALSE );
}
/*-----------------------------------------------------------*/

static void prvDigitCounterTimerCallback( TimerHandle_t xTimer )
{
/* Define the bit patterns that display numbers on the seven segment display. */
    static const unsigned short usNumbersPatterns[] = { 0x8004, 0xF204, 0x4804, 0x6004, 0x3204, 0x2404, 0x0404, 0xF104, 0x0004, 0x2004 };
    static long lCounter = 0L;
    const long lNumberOfDigits = 10L;
    unsigned short usCheckLEDState;

    /* Unfortunately the LED uses the same port as the digit counter, so remember
     * the state of the check LED.  A critical section is not required to access
     * the port as only one timer can be executing at any one time. */
    usCheckLEDState = ( FM3_GPIO->PDOR3 & mainCHECK_LED );

    /* Display the next number, counting up. */
    FM3_GPIO->PDOR3 = usNumbersPatterns[ lCounter ] | usCheckLEDState;

    /* Move onto the next digit. */
    lCounter++;

    /* Ensure the counter does not go off the end of the array. */
    if( lCounter >= lNumberOfDigits )
    {
        lCounter = 0L;
    }
}
/*-----------------------------------------------------------*/

/* The ISR executed when the user button is pushed. */
void INT0_7_Handler( void )
{
    portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

    /* The button was pushed, so ensure the LED is on before resetting the
     * LED timer.  The LED timer will turn the LED off if the button is not
     * pushed within 5000ms. */
    vParTestSetLEDFromISR( mainTIMER_CONTROLLED_LED, pdTRUE );

    /* This interrupt safe FreeRTOS function can be called from this interrupt
     * because the interrupt priority is below the
     * configMAX_SYSCALL_INTERRUPT_PRIORITY setting in FreeRTOSConfig.h. */
    xTimerResetFromISR( xLEDTimer, &xHigherPriorityTaskWoken );

    /* Clear the interrupt before leaving.  This just clears all the interrupts
     *  for simplicity, as only one is actually used in this simple demo anyway. */
    FM3_EXTI->EICL = 0x0000;

    /* If calling xTimerResetFromISR() caused a task (in this case the timer
     * service/daemon task) to unblock, and the unblocked task has a priority
     * higher than or equal to the task that was interrupted, then
     * xHigherPriorityTaskWoken will now be set to pdTRUE, and calling
     * portEND_SWITCHING_ISR() will ensure the unblocked task runs next. */
    portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
}
/*-----------------------------------------------------------*/

static void prvQueueSendTask( void * pvParameters )
{
    TickType_t xNextWakeTime;
    const unsigned long ulValueToSend = 100UL;

    /* The timer command queue will have been filled when the timer test tasks
     * were created in main() (this is part of the test they perform).  Therefore,
     * while the check and digit counter timers can be created in main(), they
     * cannot be started from main().  Once the scheduler has started, the timer
     * service	task will drain the command queue, and now the check and digit
     * counter timers can be started successfully. */
    xTimerStart( xCheckTimer, portMAX_DELAY );
    xTimerStart( xDigitCounterTimer, portMAX_DELAY );

    /* Initialise xNextWakeTime - this only needs to be done once. */
    xNextWakeTime = xTaskGetTickCount();

    for( ; ; )
    {
        /* Place this task in the blocked state until it is time to run again.
         * The block time is specified in ticks, the constant used converts ticks
         * to ms.  While in the Blocked state this task will not consume any CPU
         * time. */
        vTaskDelayUntil( &xNextWakeTime, mainQUEUE_SEND_FREQUENCY_MS );

        /* Send to the queue - causing the queue receive task to unblock and
         * toggle an LED.  0 is used as the block time so the sending operation
         * will not block - it shouldn't need to block as the queue should always
         * be empty at this point in the code. */
        xQueueSend( xQueue, &ulValueToSend, mainDONT_BLOCK );
    }
}
/*-----------------------------------------------------------*/

static void prvQueueReceiveTask( void * pvParameters )
{
    unsigned long ulReceivedValue;

    for( ; ; )
    {
        /* Wait until something arrives in the queue - this task will block
         * indefinitely provided INCLUDE_vTaskSuspend is set to 1 in
         * FreeRTOSConfig.h. */
        xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY );

        /*  To get here something must have been received from the queue, but
         * is it the expected value?  If it is, toggle the LED. */
        if( ulReceivedValue == 100UL )
        {
            vParTestToggleLED( mainTASK_CONTROLLED_LED );
        }
    }
}
/*-----------------------------------------------------------*/

static void prvSetupHardware( void )
{
    const unsigned short usButtonInputBit = 0x01U;

    SystemInit();
    SystemCoreClockUpdate();

    /* Initialise the IO used for the LEDs on the 7 segment displays. */
    vParTestInitialise();

    /* Set the switches to input (P18->P1F). */
    FM3_GPIO->DDR5 = 0x0000;
    FM3_GPIO->PFR5 = 0x0000;

    /* Assign the button input as GPIO. */
    FM3_GPIO->PFR5 |= usButtonInputBit;

    /* Button interrupt on falling edge. */
    FM3_EXTI->ELVR = 0x0003;

    /* Clear all external interrupts. */
    FM3_EXTI->EICL = 0x0000;

    /* Enable the button interrupt. */
    FM3_EXTI->ENIR |= usButtonInputBit;

    /* Setup the GPIO and the NVIC for the switch used in this simple demo. */
    NVIC_SetPriority( EXINT0_7_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
    NVIC_EnableIRQ( EXINT0_7_IRQn );
}
/*-----------------------------------------------------------*/

void vApplicationMallocFailedHook( void )
{
    /* Called if a call to pvPortMalloc() fails because there is insufficient
     * free memory available in the FreeRTOS heap.  pvPortMalloc() is called
     * internally by FreeRTOS API functions that create tasks, queues, software
     * timers, and semaphores.  The size of the FreeRTOS heap is set by the
     * configTOTAL_HEAP_SIZE configuration constant in FreeRTOSConfig.h. */
    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/

void vApplicationStackOverflowHook( TaskHandle_t pxTask,
                                    char * pcTaskName )
{
    ( void ) pcTaskName;
    ( void ) pxTask;

    /* Run time stack overflow checking is performed if
     * configconfigCHECK_FOR_STACK_OVERFLOW is defined to 1 or 2.  This hook
     * function is called if a stack overflow is detected. */
    taskDISABLE_INTERRUPTS();

    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/

void vApplicationIdleHook( void )
{
    volatile size_t xFreeStackSpace;

    /* This function is called on each cycle of the idle task.  In this case it
     * does nothing useful, other than report the amount of FreeRTOS heap that
     * remains unallocated. */
    xFreeStackSpace = xPortGetFreeHeapSize();

    if( xFreeStackSpace > 100 )
    {
        /* By now, the kernel has allocated everything it is going to, so
         * if there is a lot of heap remaining unallocated then
         * the value of configTOTAL_HEAP_SIZE in FreeRTOSConfig.h can be
         * reduced accordingly. */
    }
}
/*-----------------------------------------------------------*/

void vApplicationTickHook( void )
{
    /* Call the periodic timer test, which tests the timer API functions that
     * can be called from an ISR. */
    vTimerPeriodicISRTests();
}
/*-----------------------------------------------------------*/