diagram.json

#include "Arduino_FreeRTOS.h"
#include "semphr.h"  // add the FreeRTOS functions for Semaphores (or Flags).

// Declare a mutex Semaphore Handle which we will use to manage the Serial Port.
// It will be used to ensure only one Task is accessing this resource at any time.
SemaphoreHandle_t xSerialSemaphore;

// define two Tasks for DigitalRead & AnalogRead
void TaskDigitalRead( void *pvParameters );
void TaskAnalogRead( void *pvParameters );

// the setup function runs once when you press reset or power the board
void setup() {

  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
  
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB, on LEONARDO, MICRO, YUN, and other 32u4 based boards.
  }

  // Semaphores are useful to stop a Task proceeding, where it should be paused to wait,
  // because it is sharing a resource, such as the Serial port.
  // Semaphores should only be used whilst the scheduler is running, but we can set it up here.
  if ( xSerialSemaphore == NULL )  // Check to confirm that the Serial Semaphore has not already been created.
  {
    xSerialSemaphore = xSemaphoreCreateMutex();  // Create a mutex semaphore we will use to manage the Serial Port
    if ( ( xSerialSemaphore ) != NULL )
      xSemaphoreGive( ( xSerialSemaphore ) );  // Make the Serial Port available for use, by "Giving" the Semaphore.
  }

  // Now set up two Tasks to run independently.
  xTaskCreate(
    TaskDigitalRead
    ,  "DigitalRead"  // A name just for humans
    ,  128  // This stack size can be checked & adjusted by reading the Stack Highwater
    ,  NULL //Parameters for the task
    ,  2  // Priority, with 3 (configMAX_PRIORITIES - 1) being the highest, and 0 being the lowest.
    ,  NULL ); //Task Handle

  xTaskCreate(
    TaskAnalogRead
    ,  "AnalogRead" // A name just for humans
    ,  128  // Stack size
    ,  NULL //Parameters for the task
    ,  1  // Priority
    ,  NULL ); //Task Handle

  // Now the Task scheduler, which takes over control of scheduling individual Tasks, is automatically started.
}

void loop()
{
  // Empty. Things are done in Tasks.
}

/*--------------------------------------------------*/
/*---------------------- Tasks ---------------------*/
/*--------------------------------------------------*/

void TaskDigitalRead( void *pvParameters __attribute__((unused)) )  // This is a Task.
{
  /*
    DigitalReadSerial
    Reads a digital input on pin 2, prints the result to the serial monitor

    This example code is in the public domain.
  */

  // digital pin 2 has a pushbutton attached to it. Give it a name:
  uint8_t pushButton = 2;

  // make the pushbutton's pin an input:
  pinMode(pushButton, INPUT);

  for (;;) // A Task shall never return or exit.
  {
    // read the input pin:
    int buttonState = digitalRead(pushButton);

    // See if we can obtain or "Take" the Serial Semaphore.
    // If the semaphore is not available, wait 5 ticks of the Scheduler to see if it becomes free.
    if ( xSemaphoreTake( xSerialSemaphore, ( TickType_t ) 5 ) == pdTRUE )
    {
      // We were able to obtain or "Take" the semaphore and can now access the shared resource.
      // We want to have the Serial Port for us alone, as it takes some time to print,
      // so we don't want it getting stolen during the middle of a conversion.
      // print out the state of the button:
      Serial.println(buttonState);

      xSemaphoreGive( xSerialSemaphore ); // Now free or "Give" the Serial Port for others.
    }

    vTaskDelay(1);  // one tick delay (15ms) in between reads for stability
  }
}

void TaskAnalogRead( void *pvParameters __attribute__((unused)) )  // This is a Task.
{

  for (;;)
  {
    // read the input on analog pin 0:
    int sensorValue = analogRead(A0);

    // See if we can obtain or "Take" the Serial Semaphore.
    // If the semaphore is not available, wait 5 ticks of the Scheduler to see if it becomes free.
    if ( xSemaphoreTake( xSerialSemaphore, ( TickType_t ) 5 ) == pdTRUE )
    {
      // We were able to obtain or "Take" the semaphore and can now access the shared resource.
      // We want to have the Serial Port for us alone, as it takes some time to print,
      // so we don't want it getting stolen during the middle of a conversion.
      // print out the value you read:
      Serial.println(sensorValue);

      xSemaphoreGive( xSerialSemaphore ); // Now free or "Give" the Serial Port for others.
    }

    vTaskDelay(1);  // one tick delay (15ms) in between reads for stability
  }
}


AnalogRead_DigitalRead.ino

Arduino_FreeRTOS.h

event_groups.c

event_groups.h

/*
 * FreeRTOS Kernel V10.4.6
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
 */

#ifndef FREERTOS_CONFIG_H
#define FREERTOS_CONFIG_H

#include <avr/io.h>

/*-----------------------------------------------------------
 * Application specific definitions.
 *
 * These definitions should be adjusted for your particular hardware and
 * application requirements.
 *
 * THESE PARAMETERS ARE DESCRIBED WITHIN THE 'CONFIGURATION' SECTION OF THE
 * FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE.
 *
 * See https://www.freertos.org/a00110.html.
 *----------------------------------------------------------*/

/* And on to the things the same no matter the AVR type... */
#define configUSE_PREEMPTION                1

#define configCPU_CLOCK_HZ                  ( ( uint32_t ) F_CPU )          // This F_CPU variable set by the environment
#define configMAX_PRIORITIES                4
#define configIDLE_SHOULD_YIELD             1
#define configMINIMAL_STACK_SIZE            ( 192 )
#define configMAX_TASK_NAME_LEN             ( 8 )

#define configQUEUE_REGISTRY_SIZE           0
#define configCHECK_FOR_STACK_OVERFLOW      1

#define configUSE_TRACE_FACILITY            0
#define configUSE_16_BIT_TICKS              1

#define configUSE_MUTEXES                   1
#define configUSE_RECURSIVE_MUTEXES         1
#define configUSE_COUNTING_SEMAPHORES       1
#define configUSE_TIME_SLICING              1
#define configUSE_QUEUE_SETS                0
#define configUSE_MALLOC_FAILED_HOOK        1

#define configSUPPORT_DYNAMIC_ALLOCATION    1
#define configSUPPORT_STATIC_ALLOCATION     0

#define configUSE_IDLE_HOOK                 1
#define configUSE_TICK_HOOK                 0

/* Delay definition - here, the user can choose which delay implementation is required.
 * The default is to change nothing. */
#define configUSE_PORT_DELAY                1

/* Timer definitions. */
#define configUSE_TIMERS                    1
#define configTIMER_TASK_PRIORITY           configMAX_PRIORITIES-1
#define configTIMER_QUEUE_LENGTH            ( 10 )
#define configTIMER_TASK_STACK_DEPTH        ( 85 )

/* Set the stack depth type to be uint16_t. */
#define configSTACK_DEPTH_TYPE              uint16_t

/* Set the stack pointer type to be uint16_t, otherwise it defaults to unsigned long */
#define portPOINTER_SIZE_TYPE               uint16_t

/* Set the following definitions to 1 to include the API function, or zero
to exclude the API function. */

#define INCLUDE_vTaskPrioritySet                1
#define INCLUDE_uxTaskPriorityGet               1
#define INCLUDE_vTaskDelete                     1
#define INCLUDE_vTaskCleanUpResources           1
#define INCLUDE_vTaskSuspend                    1
#define INCLUDE_vResumeFromISR                  1
#define INCLUDE_xTaskDelayUntil                 1
#define INCLUDE_vTaskDelay                      1
#define INCLUDE_xTaskGetSchedulerState          0
#define INCLUDE_xTaskGetIdleTaskHandle          0 // create an idle task handle.
#define INCLUDE_xTaskGetCurrentTaskHandle       1
#define INCLUDE_uxTaskGetStackHighWaterMark     1

#define configMAX(a,b)  ({ __typeof__ (a) _a = (a); __typeof__ (b) _b = (b); _a > _b ? _a : _b; })
#define configMIN(a,b)  ({ __typeof__ (a) _a = (a); __typeof__ (b) _b = (b); _a < _b ? _a : _b; })

/**
 * configASSERT macro: https://www.freertos.org/a00110.html#configASSERT
 */
#ifndef configASSERT
    #define configDEFAULT_ASSERT 0
#else
    /**
     * Enable configASSERT macro if it is defined.
     */
    #ifndef configDEFAULT_ASSERT
        #define configDEFAULT_ASSERT 1
    #endif

    /**
     * Define a hook method for configASSERT macro if configASSERT is enabled.
     */
    #if configDEFAULT_ASSERT == 1
        extern void vApplicationAssertHook();
        #define configASSERT( x ) if (( x ) == 0) { vApplicationAssertHook(); }
    #endif
#endif


#endif /* FREERTOS_CONFIG_H */


FreeRTOSConfig.h

/*
 * Copyright (C) 2022 Phillip Stevens  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.
 *
 *
 * This file is NOT part of the FreeRTOS distribution.
 *
 */

#ifndef freeRTOSVariant_h
#define freeRTOSVariant_h

#ifdef __cplusplus
extern "C" {
#endif

#include <avr/io.h>
#include <avr/wdt.h>

// System Tick - Scheduler timer
// Use the Watchdog timer, and choose the rate at which scheduler interrupts will occur.

#ifndef portUSE_WDTO
    #define portUSE_WDTO        WDTO_15MS    // portUSE_WDTO to use the Watchdog Timer for xTaskIncrementTick
#endif

/* Watchdog period options:     WDTO_15MS
                                WDTO_30MS
                                WDTO_60MS
                                WDTO_120MS
                                WDTO_250MS
                                WDTO_500MS
                                WDTO_1S
                                WDTO_2S
*/

/* Watchdog Timer is 128kHz nominal, but 120 kHz at 5V DC and 25 degrees is actually more accurate, from data sheet. */
#define configTICK_RATE_HZ  ( (TickType_t)( (uint32_t)128000 >> (portUSE_WDTO + 11) ) )  // 2^11 = 2048 WDT scaler for 128kHz Timer

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

#ifndef INC_TASK_H
#include "Arduino_FreeRTOS.h"
#include "task.h"
#endif

void initVariant(void);

void vApplicationIdleHook( void );

void vApplicationMallocFailedHook( void );
void vApplicationStackOverflowHook( TaskHandle_t xTask, char * pcTaskName );

void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
                                    StackType_t ** ppxIdleTaskStackBuffer,
                                    configSTACK_DEPTH_TYPE * pulIdleTaskStackSize );
void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,
                                     StackType_t ** ppxTimerTaskStackBuffer,
                                     configSTACK_DEPTH_TYPE * pulTimerTaskStackSize );

#ifdef __cplusplus
}
#endif

#endif // freeRTOSVariant_h


FreeRTOSVariant.h

/*
 * FreeRTOS Kernel V10.4.6
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
 */


/*
 * Implementation of pvPortMalloc() and vPortFree() that relies on the
 * compilers own malloc() and free() implementations.
 *
 * This file can only be used if the linker is configured to to generate
 * a heap memory area.
 *
 * See heap_1.c, heap_2.c and heap_4.c for alternative implementations, and the
 * memory management pages of https://www.FreeRTOS.org for more information.
 */

#include <stdlib.h>

/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
 * all the API functions to use the MPU wrappers.  That should only be done when
 * task.h is included from an application file. */
#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE

#include "Arduino_FreeRTOS.h"
#include "task.h"

#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE

#if( configSUPPORT_DYNAMIC_ALLOCATION > 0 )

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

void * pvPortMalloc( size_t xWantedSize )
{
    void * pvReturn;

    vTaskSuspendAll();
    {
        pvReturn = malloc( xWantedSize );
        traceMALLOC( pvReturn, xWantedSize );
    }
    ( void ) xTaskResumeAll();

    #if ( configUSE_MALLOC_FAILED_HOOK == 1 )
    {
        if( pvReturn == NULL )
        {
            vApplicationMallocFailedHook();
        }
    }
    #endif

    return pvReturn;
}
/*-----------------------------------------------------------*/

void vPortFree( void * pv )
{
    if( pv != NULL )
    {
        vTaskSuspendAll();
        {
            free( pv );
            traceFREE( pv, 0 );
        }
        ( void ) xTaskResumeAll();
    }
}

#endif /* ( configSUPPORT_DYNAMIC_ALLOCATION > 0 ) */


heap_3.c

/*
 * FreeRTOS Kernel V10.4.6
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
 */


#include <stdlib.h>

/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
 * all the API functions to use the MPU wrappers.  That should only be done when
 * task.h is included from an application file. */
#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE

#include "Arduino_FreeRTOS.h"
#include "list.h"

/* Lint e9021, e961 and e750 are suppressed as a MISRA exception justified
 * because the MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be
 * defined for the header files above, but not in this file, in order to
 * generate the correct privileged Vs unprivileged linkage and placement. */
#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*lint !e961 !e750 !e9021. */

/*-----------------------------------------------------------
* PUBLIC LIST API documented in list.h
*----------------------------------------------------------*/

void vListInitialise( List_t * const pxList )
{
    /* The list structure contains a list item which is used to mark the
     * end of the list.  To initialise the list the list end is inserted
     * as the only list entry. */
    pxList->pxIndex = ( ListItem_t * ) &( pxList->xListEnd ); /*lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM.  This is checked and valid. */

    listSET_FIRST_LIST_ITEM_INTEGRITY_CHECK_VALUE( &( pxList->xListEnd ) );

    /* The list end value is the highest possible value in the list to
     * ensure it remains at the end of the list. */
    pxList->xListEnd.xItemValue = portMAX_DELAY;

    /* The list end next and previous pointers point to itself so we know
     * when the list is empty. */
    pxList->xListEnd.pxNext = ( ListItem_t * ) &( pxList->xListEnd );     /*lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM.  This is checked and valid. */
    pxList->xListEnd.pxPrevious = ( ListItem_t * ) &( pxList->xListEnd ); /*lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM.  This is checked and valid. */

    /* Initialize the remaining fields of xListEnd when it is a proper ListItem_t */
    #if ( configUSE_MINI_LIST_ITEM == 0 )
    {
        pxList->xListEnd.pvOwner = NULL;
        pxList->xListEnd.pxContainer = NULL;
        listSET_SECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE( &( pxList->xListEnd ) );
    }
    #endif

    pxList->uxNumberOfItems = ( UBaseType_t ) 0U;

    /* Write known values into the list if
     * configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES is set to 1. */
    listSET_LIST_INTEGRITY_CHECK_1_VALUE( pxList );
    listSET_LIST_INTEGRITY_CHECK_2_VALUE( pxList );
}
/*-----------------------------------------------------------*/

void vListInitialiseItem( ListItem_t * const pxItem )
{
    /* Make sure the list item is not recorded as being on a list. */
    pxItem->pxContainer = NULL;

    /* Write known values into the list item if
     * configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES is set to 1. */
    listSET_FIRST_LIST_ITEM_INTEGRITY_CHECK_VALUE( pxItem );
    listSET_SECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE( pxItem );
}
/*-----------------------------------------------------------*/

void vListInsertEnd( List_t * const pxList,
                     ListItem_t * const pxNewListItem )
{
    ListItem_t * const pxIndex = pxList->pxIndex;

    /* Only effective when configASSERT() is also defined, these tests may catch
     * the list data structures being overwritten in memory.  They will not catch
     * data errors caused by incorrect configuration or use of FreeRTOS. */
    listTEST_LIST_INTEGRITY( pxList );
    listTEST_LIST_ITEM_INTEGRITY( pxNewListItem );

    /* Insert a new list item into pxList, but rather than sort the list,
     * makes the new list item the last item to be removed by a call to
     * listGET_OWNER_OF_NEXT_ENTRY(). */
    pxNewListItem->pxNext = pxIndex;
    pxNewListItem->pxPrevious = pxIndex->pxPrevious;

    /* Only used during decision coverage testing. */
    mtCOVERAGE_TEST_DELAY();

    pxIndex->pxPrevious->pxNext = pxNewListItem;
    pxIndex->pxPrevious = pxNewListItem;

    /* Remember which list the item is in. */
    pxNewListItem->pxContainer = pxList;

    ( pxList->uxNumberOfItems )++;
}
/*-----------------------------------------------------------*/

void vListInsert( List_t * const pxList,
                  ListItem_t * const pxNewListItem )
{
    ListItem_t * pxIterator;
    const TickType_t xValueOfInsertion = pxNewListItem->xItemValue;

    /* Only effective when configASSERT() is also defined, these tests may catch
     * the list data structures being overwritten in memory.  They will not catch
     * data errors caused by incorrect configuration or use of FreeRTOS. */
    listTEST_LIST_INTEGRITY( pxList );
    listTEST_LIST_ITEM_INTEGRITY( pxNewListItem );

    /* Insert the new list item into the list, sorted in xItemValue order.
     *
     * If the list already contains a list item with the same item value then the
     * new list item should be placed after it.  This ensures that TCBs which are
     * stored in ready lists (all of which have the same xItemValue value) get a
     * share of the CPU.  However, if the xItemValue is the same as the back marker
     * the iteration loop below will not end.  Therefore the value is checked
     * first, and the algorithm slightly modified if necessary. */
    if( xValueOfInsertion == portMAX_DELAY )
    {
        pxIterator = pxList->xListEnd.pxPrevious;
    }
    else
    {
        /* *** NOTE ***********************************************************
        *  If you find your application is crashing here then likely causes are
        *  listed below.  In addition see https://www.FreeRTOS.org/FAQHelp.html for
        *  more tips, and ensure configASSERT() is defined!
        *  https://www.FreeRTOS.org/a00110.html#configASSERT
        *
        *   1) Stack overflow -
        *      see https://www.FreeRTOS.org/Stacks-and-stack-overflow-checking.html
        *   2) Incorrect interrupt priority assignment, especially on Cortex-M
        *      parts where numerically high priority values denote low actual
        *      interrupt priorities, which can seem counter intuitive.  See
        *      https://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html and the definition
        *      of configMAX_SYSCALL_INTERRUPT_PRIORITY on
        *      https://www.FreeRTOS.org/a00110.html
        *   3) Calling an API function from within a critical section or when
        *      the scheduler is suspended, or calling an API function that does
        *      not end in "FromISR" from an interrupt.
        *   4) Using a queue or semaphore before it has been initialised or
        *      before the scheduler has been started (are interrupts firing
        *      before vTaskStartScheduler() has been called?).
        *   5) If the FreeRTOS port supports interrupt nesting then ensure that
        *      the priority of the tick interrupt is at or below
        *      configMAX_SYSCALL_INTERRUPT_PRIORITY.
        **********************************************************************/

        for( pxIterator = ( ListItem_t * ) &( pxList->xListEnd ); pxIterator->pxNext->xItemValue <= xValueOfInsertion; pxIterator = pxIterator->pxNext ) /*lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM.  This is checked and valid. *//*lint !e440 The iterator moves to a different value, not xValueOfInsertion. */
        {
            /* There is nothing to do here, just iterating to the wanted
             * insertion position. */
        }
    }

    pxNewListItem->pxNext = pxIterator->pxNext;
    pxNewListItem->pxNext->pxPrevious = pxNewListItem;
    pxNewListItem->pxPrevious = pxIterator;
    pxIterator->pxNext = pxNewListItem;

    /* Remember which list the item is in.  This allows fast removal of the
     * item later. */
    pxNewListItem->pxContainer = pxList;

    ( pxList->uxNumberOfItems )++;
}
/*-----------------------------------------------------------*/

UBaseType_t uxListRemove( ListItem_t * const pxItemToRemove )
{
/* The list item knows which list it is in.  Obtain the list from the list
 * item. */
    List_t * const pxList = pxItemToRemove->pxContainer;

    pxItemToRemove->pxNext->pxPrevious = pxItemToRemove->pxPrevious;
    pxItemToRemove->pxPrevious->pxNext = pxItemToRemove->pxNext;

    /* Only used during decision coverage testing. */
    mtCOVERAGE_TEST_DELAY();

    /* Make sure the index is left pointing to a valid item. */
    if( pxList->pxIndex == pxItemToRemove )
    {
        pxList->pxIndex = pxItemToRemove->pxPrevious;
    }
    else
    {
        mtCOVERAGE_TEST_MARKER();
    }

    pxItemToRemove->pxContainer = NULL;
    ( pxList->uxNumberOfItems )--;

    return pxList->uxNumberOfItems;
}
/*-----------------------------------------------------------*/


list.c

list.h

/*
 * FreeRTOS Kernel V10.4.6
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
 */

#ifndef MPU_WRAPPERS_H
#define MPU_WRAPPERS_H

/* This file redefines API functions to be called through a wrapper macro, but
 * only for ports that are using the MPU. */
#if ( portUSING_MPU_WRAPPERS == 1 )

/* MPU_WRAPPERS_INCLUDED_FROM_API_FILE will be defined when this file is
 * included from queue.c or task.c to prevent it from having an effect within
 * those files. */
    #ifndef MPU_WRAPPERS_INCLUDED_FROM_API_FILE

/*
 * Map standard (non MPU) API functions to equivalents that start
 * "MPU_".  This will cause the application code to call the MPU_
 * version, which wraps the non-MPU version with privilege promoting
 * then demoting code, so the kernel code always runs will full
 * privileges.
 */

/* Map standard task.h API functions to the MPU equivalents. */
        #define xTaskCreate                            MPU_xTaskCreate
        #define xTaskCreateStatic                      MPU_xTaskCreateStatic
        #define vTaskDelete                            MPU_vTaskDelete
        #define vTaskDelay                             MPU_vTaskDelay
        #define xTaskDelayUntil                        MPU_xTaskDelayUntil
        #define xTaskAbortDelay                        MPU_xTaskAbortDelay
        #define uxTaskPriorityGet                      MPU_uxTaskPriorityGet
        #define eTaskGetState                          MPU_eTaskGetState
        #define vTaskGetInfo                           MPU_vTaskGetInfo
        #define vTaskPrioritySet                       MPU_vTaskPrioritySet
        #define vTaskSuspend                           MPU_vTaskSuspend
        #define vTaskResume                            MPU_vTaskResume
        #define vTaskSuspendAll                        MPU_vTaskSuspendAll
        #define xTaskResumeAll                         MPU_xTaskResumeAll
        #define xTaskGetTickCount                      MPU_xTaskGetTickCount
        #define uxTaskGetNumberOfTasks                 MPU_uxTaskGetNumberOfTasks
        #define pcTaskGetName                          MPU_pcTaskGetName
        #define xTaskGetHandle                         MPU_xTaskGetHandle
        #define uxTaskGetStackHighWaterMark            MPU_uxTaskGetStackHighWaterMark
        #define uxTaskGetStackHighWaterMark2           MPU_uxTaskGetStackHighWaterMark2
        #define vTaskSetApplicationTaskTag             MPU_vTaskSetApplicationTaskTag
        #define xTaskGetApplicationTaskTag             MPU_xTaskGetApplicationTaskTag
        #define vTaskSetThreadLocalStoragePointer      MPU_vTaskSetThreadLocalStoragePointer
        #define pvTaskGetThreadLocalStoragePointer     MPU_pvTaskGetThreadLocalStoragePointer
        #define xTaskCallApplicationTaskHook           MPU_xTaskCallApplicationTaskHook
        #define xTaskGetIdleTaskHandle                 MPU_xTaskGetIdleTaskHandle
        #define uxTaskGetSystemState                   MPU_uxTaskGetSystemState
        #define vTaskList                              MPU_vTaskList
        #define vTaskGetRunTimeStats                   MPU_vTaskGetRunTimeStats
        #define ulTaskGetIdleRunTimeCounter            MPU_ulTaskGetIdleRunTimeCounter
        #define ulTaskGetIdleRunTimePercent            MPU_ulTaskGetIdleRunTimePercent
        #define xTaskGenericNotify                     MPU_xTaskGenericNotify
        #define xTaskGenericNotifyWait                 MPU_xTaskGenericNotifyWait
        #define ulTaskGenericNotifyTake                MPU_ulTaskGenericNotifyTake
        #define xTaskGenericNotifyStateClear           MPU_xTaskGenericNotifyStateClear
        #define ulTaskGenericNotifyValueClear          MPU_ulTaskGenericNotifyValueClear
        #define xTaskCatchUpTicks                      MPU_xTaskCatchUpTicks

        #define xTaskGetCurrentTaskHandle              MPU_xTaskGetCurrentTaskHandle
        #define vTaskSetTimeOutState                   MPU_vTaskSetTimeOutState
        #define xTaskCheckForTimeOut                   MPU_xTaskCheckForTimeOut
        #define xTaskGetSchedulerState                 MPU_xTaskGetSchedulerState

/* Map standard queue.h API functions to the MPU equivalents. */
        #define xQueueGenericSend                      MPU_xQueueGenericSend
        #define xQueueReceive                          MPU_xQueueReceive
        #define xQueuePeek                             MPU_xQueuePeek
        #define xQueueSemaphoreTake                    MPU_xQueueSemaphoreTake
        #define uxQueueMessagesWaiting                 MPU_uxQueueMessagesWaiting
        #define uxQueueSpacesAvailable                 MPU_uxQueueSpacesAvailable
        #define vQueueDelete                           MPU_vQueueDelete
        #define xQueueCreateMutex                      MPU_xQueueCreateMutex
        #define xQueueCreateMutexStatic                MPU_xQueueCreateMutexStatic
        #define xQueueCreateCountingSemaphore          MPU_xQueueCreateCountingSemaphore
        #define xQueueCreateCountingSemaphoreStatic    MPU_xQueueCreateCountingSemaphoreStatic
        #define xQueueGetMutexHolder                   MPU_xQueueGetMutexHolder
        #define xQueueTakeMutexRecursive               MPU_xQueueTakeMutexRecursive
        #define xQueueGiveMutexRecursive               MPU_xQueueGiveMutexRecursive
        #define xQueueGenericCreate                    MPU_xQueueGenericCreate
        #define xQueueGenericCreateStatic              MPU_xQueueGenericCreateStatic
        #define xQueueCreateSet                        MPU_xQueueCreateSet
        #define xQueueAddToSet                         MPU_xQueueAddToSet
        #define xQueueRemoveFromSet                    MPU_xQueueRemoveFromSet
        #define xQueueSelectFromSet                    MPU_xQueueSelectFromSet
        #define xQueueGenericReset                     MPU_xQueueGenericReset

        #if ( configQUEUE_REGISTRY_SIZE > 0 )
            #define vQueueAddToRegistry                MPU_vQueueAddToRegistry
            #define vQueueUnregisterQueue              MPU_vQueueUnregisterQueue
            #define pcQueueGetName                     MPU_pcQueueGetName
        #endif

/* Map standard timer.h API functions to the MPU equivalents. */
        #define xTimerCreate                           MPU_xTimerCreate
        #define xTimerCreateStatic                     MPU_xTimerCreateStatic
        #define pvTimerGetTimerID                      MPU_pvTimerGetTimerID
        #define vTimerSetTimerID                       MPU_vTimerSetTimerID
        #define xTimerIsTimerActive                    MPU_xTimerIsTimerActive
        #define xTimerGetTimerDaemonTaskHandle         MPU_xTimerGetTimerDaemonTaskHandle
        #define xTimerPendFunctionCall                 MPU_xTimerPendFunctionCall
        #define pcTimerGetName                         MPU_pcTimerGetName
        #define vTimerSetReloadMode                    MPU_vTimerSetReloadMode
        #define uxTimerGetReloadMode                   MPU_uxTimerGetReloadMode
        #define xTimerGetPeriod                        MPU_xTimerGetPeriod
        #define xTimerGetExpiryTime                    MPU_xTimerGetExpiryTime
        #define xTimerGenericCommand                   MPU_xTimerGenericCommand

/* Map standard event_group.h API functions to the MPU equivalents. */
        #define xEventGroupCreate                      MPU_xEventGroupCreate
        #define xEventGroupCreateStatic                MPU_xEventGroupCreateStatic
        #define xEventGroupWaitBits                    MPU_xEventGroupWaitBits
        #define xEventGroupClearBits                   MPU_xEventGroupClearBits
        #define xEventGroupSetBits                     MPU_xEventGroupSetBits
        #define xEventGroupSync                        MPU_xEventGroupSync
        #define vEventGroupDelete                      MPU_vEventGroupDelete

/* Map standard message/stream_buffer.h API functions to the MPU
 * equivalents. */
        #define xStreamBufferSend                      MPU_xStreamBufferSend
        #define xStreamBufferReceive                   MPU_xStreamBufferReceive
        #define xStreamBufferNextMessageLengthBytes    MPU_xStreamBufferNextMessageLengthBytes
        #define vStreamBufferDelete                    MPU_vStreamBufferDelete
        #define xStreamBufferIsFull                    MPU_xStreamBufferIsFull
        #define xStreamBufferIsEmpty                   MPU_xStreamBufferIsEmpty
        #define xStreamBufferReset                     MPU_xStreamBufferReset
        #define xStreamBufferSpacesAvailable           MPU_xStreamBufferSpacesAvailable
        #define xStreamBufferBytesAvailable            MPU_xStreamBufferBytesAvailable
        #define xStreamBufferSetTriggerLevel           MPU_xStreamBufferSetTriggerLevel
        #define xStreamBufferGenericCreate             MPU_xStreamBufferGenericCreate
        #define xStreamBufferGenericCreateStatic       MPU_xStreamBufferGenericCreateStatic


/* Remove the privileged function macro, but keep the PRIVILEGED_DATA
 * macro so applications can place data in privileged access sections
 * (useful when using statically allocated objects). */
        #define PRIVILEGED_FUNCTION
        #define PRIVILEGED_DATA    __attribute__ ((section( "privileged_data" )))
        #define FREERTOS_SYSTEM_CALL

    #else /* MPU_WRAPPERS_INCLUDED_FROM_API_FILE */

/* Ensure API functions go in the privileged execution section. */
        #define PRIVILEGED_FUNCTION     __attribute__ ((section( "privileged_functions" )))
        #define PRIVILEGED_DATA         __attribute__ ((section( "privileged_data" )))
        #define FREERTOS_SYSTEM_CALL    __attribute__ ((section( "freertos_system_calls" )))

/**
 * @brief Calls the port specific code to raise the privilege.
 *
 * Sets xRunningPrivileged to pdFALSE if privilege was raised, else sets
 * it to pdTRUE.
 */
        #define xPortRaisePrivilege( xRunningPrivileged )                  \
    {                                                                      \
        /* Check whether the processor is already privileged. */           \
        xRunningPrivileged = portIS_PRIVILEGED();                          \
                                                                           \
        /* If the processor is not already privileged, raise privilege. */ \
        if( xRunningPrivileged == pdFALSE )                                \
        {                                                                  \
            portRAISE_PRIVILEGE();                                         \
        }                                                                  \
    }

/**
 * @brief If xRunningPrivileged is not pdTRUE, calls the port specific
 * code to reset the privilege, otherwise does nothing.
 */
        #define vPortResetPrivilege( xRunningPrivileged ) \
    {                                                     \
        if( xRunningPrivileged == pdFALSE )               \
        {                                                 \
            portRESET_PRIVILEGE();                        \
        }                                                 \
    }

    #endif /* MPU_WRAPPERS_INCLUDED_FROM_API_FILE */

#else /* portUSING_MPU_WRAPPERS */

    #if defined(__AVR_ATmega2560__) || defined(__AVR_ATmega2561__)    // Mega with 2560
        #define PRIVILEGED_FUNCTION     __attribute__ ((hot))
        #define PRIVILEGED_DATA
        #define FREERTOS_SYSTEM_CALL    __attribute__ ((hot))
        #define portUSING_MPU_WRAPPERS 0
    #elif defined(__AVR_ATmega640__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1281__) || defined(__AVR_ATmega664P__) || defined(__AVR_ATmega1284P__) || defined(__AVR_ATmega1284PA__) // Goldilocks with 1284p
        #define PRIVILEGED_FUNCTION     __attribute__ ((hot))
        #define PRIVILEGED_DATA
        #define FREERTOS_SYSTEM_CALL    __attribute__ ((hot))
        #define portUSING_MPU_WRAPPERS 0
    #else                                                            // Uno with 328p or Leonardo with 32u4
        #define PRIVILEGED_FUNCTION     __attribute__ ((hot))
        #define PRIVILEGED_DATA
        #define FREERTOS_SYSTEM_CALL    __attribute__ ((hot))
        #define portUSING_MPU_WRAPPERS 0
    #endif

#endif /* portUSING_MPU_WRAPPERS */


#endif /* MPU_WRAPPERS_H */


mpu_wrappers.h

port.c

/*
 * FreeRTOS Kernel V10.4.6
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
 */

/*-----------------------------------------------------------
* Portable layer API.  Each function must be defined for each port.
*----------------------------------------------------------*/

#ifndef PORTABLE_H
#define PORTABLE_H

/* Each FreeRTOS port has a unique portmacro.h header file.  Originally a
 * pre-processor definition was used to ensure the pre-processor found the correct
 * portmacro.h file for the port being used.  That scheme was deprecated in favour
 * of setting the compiler's include path such that it found the correct
 * portmacro.h file - removing the need for the constant and allowing the
 * portmacro.h file to be located anywhere in relation to the port being used.
 * Purely for reasons of backward compatibility the old method is still valid, but
 * to make it clear that new projects should not use it, support for the port
 * specific constants has been moved into the deprecated_definitions.h header
 * file. */
//#include "deprecated_definitions.h"

/* If portENTER_CRITICAL is not defined then including deprecated_definitions.h
 * did not result in a portmacro.h header file being included - and it should be
 * included here.  In this case the path to the correct portmacro.h header file
 * must be set in the compiler's include path. */
#ifndef portENTER_CRITICAL
    #include "portmacro.h"
#endif

#if portBYTE_ALIGNMENT == 32
    #define portBYTE_ALIGNMENT_MASK     ( 0x001f )
#elif portBYTE_ALIGNMENT == 16
    #define portBYTE_ALIGNMENT_MASK     ( 0x000f )
#elif portBYTE_ALIGNMENT == 8
    #define portBYTE_ALIGNMENT_MASK     ( 0x0007 )
#elif portBYTE_ALIGNMENT == 4
    #define portBYTE_ALIGNMENT_MASK     ( 0x0003 )
#elif portBYTE_ALIGNMENT == 2
    #define portBYTE_ALIGNMENT_MASK     ( 0x0001 )
#elif portBYTE_ALIGNMENT == 1
    #define portBYTE_ALIGNMENT_MASK     ( 0x0000 )
#else /* if portBYTE_ALIGNMENT == 32 */
    #error "Invalid portBYTE_ALIGNMENT definition"
#endif /* if portBYTE_ALIGNMENT == 32 */

#ifndef portUSING_MPU_WRAPPERS
    #define portUSING_MPU_WRAPPERS      0
#endif

#ifndef portNUM_CONFIGURABLE_REGIONS
    #define portNUM_CONFIGURABLE_REGIONS    1
#endif

#ifndef portHAS_STACK_OVERFLOW_CHECKING
    #define portHAS_STACK_OVERFLOW_CHECKING    0
#endif

#ifndef portARCH_NAME
    #define portARCH_NAME               NULL
#endif

#if configUSE_PORT_DELAY == 1
/*
 * If configUSE_PORT_DELAY is defined,
 * delay() is implemented as either the Arduino delay()
 * if the delay is less than one Tick, or
 * otherwise as FreeRTOS vTaskDelay() for longer delays.
 */

#ifndef delay
    #define delay                       vPortDelay
#endif

#endif

#ifndef configSTACK_ALLOCATION_FROM_SEPARATE_HEAP
    /* Defaults to 0 for backward compatibility. */
    #define configSTACK_ALLOCATION_FROM_SEPARATE_HEAP    0
#endif

/* *INDENT-OFF* */
#ifdef __cplusplus
    extern "C" {
#endif
/* *INDENT-ON* */

#include "mpu_wrappers.h"

/*
 * Setup the stack of a new task so it is ready to be placed under the
 * scheduler control.  The registers have to be placed on the stack in
 * the order that the port expects to find them.
 *
 */
#if ( portUSING_MPU_WRAPPERS == 1 )
    #if ( portHAS_STACK_OVERFLOW_CHECKING == 1 )
        StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
                                             StackType_t * pxEndOfStack,
                                             TaskFunction_t pxCode,
                                             void * pvParameters,
                                             BaseType_t xRunPrivileged ) PRIVILEGED_FUNCTION;
    #else
        StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
                                             TaskFunction_t pxCode,
                                             void * pvParameters,
                                             BaseType_t xRunPrivileged ) PRIVILEGED_FUNCTION;
    #endif
#else /* if ( portUSING_MPU_WRAPPERS == 1 ) */
    #if ( portHAS_STACK_OVERFLOW_CHECKING == 1 )
        StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
                                             StackType_t * pxEndOfStack,
                                             TaskFunction_t pxCode,
                                             void * pvParameters ) PRIVILEGED_FUNCTION;
    #else
        StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
                                             TaskFunction_t pxCode,
                                             void * pvParameters ) PRIVILEGED_FUNCTION;
    #endif
#endif /* if ( portUSING_MPU_WRAPPERS == 1 ) */

/* Used by heap_5.c to define the start address and size of each memory region
 * that together comprise the total FreeRTOS heap space. */
typedef struct HeapRegion
{
    uint8_t * pucStartAddress;
    size_t xSizeInBytes;
} HeapRegion_t;

/* Used to pass information about the heap out of vPortGetHeapStats(). */
typedef struct xHeapStats
{
    size_t xAvailableHeapSpaceInBytes;      /* The total heap size currently available - this is the sum of all the free blocks, not the largest block that can be allocated. */
    size_t xSizeOfLargestFreeBlockInBytes;  /* The maximum size, in bytes, of all the free blocks within the heap at the time vPortGetHeapStats() is called. */
    size_t xSizeOfSmallestFreeBlockInBytes; /* The minimum size, in bytes, of all the free blocks within the heap at the time vPortGetHeapStats() is called. */
    size_t xNumberOfFreeBlocks;             /* The number of free memory blocks within the heap at the time vPortGetHeapStats() is called. */
    size_t xMinimumEverFreeBytesRemaining;  /* The minimum amount of total free memory (sum of all free blocks) there has been in the heap since the system booted. */
    size_t xNumberOfSuccessfulAllocations;  /* The number of calls to pvPortMalloc() that have returned a valid memory block. */
    size_t xNumberOfSuccessfulFrees;        /* The number of calls to vPortFree() that has successfully freed a block of memory. */
} HeapStats_t;

/*
 * Used to define multiple heap regions for use by heap_5.c.  This function
 * must be called before any calls to pvPortMalloc() - not creating a task,
 * queue, semaphore, mutex, software timer, event group, etc. will result in
 * pvPortMalloc being called.
 *
 * pxHeapRegions passes in an array of HeapRegion_t structures - each of which
 * defines a region of memory that can be used as the heap.  The array is
 * terminated by a HeapRegions_t structure that has a size of 0.  The region
 * with the lowest start address must appear first in the array.
 */
void vPortDefineHeapRegions( const HeapRegion_t * const pxHeapRegions ) PRIVILEGED_FUNCTION;

/*
 * Returns a HeapStats_t structure filled with information about the current
 * heap state.
 */
void vPortGetHeapStats( HeapStats_t * pxHeapStats );

/*
 * Map to the memory management routines required for the port.
 */
void * pvPortMalloc( size_t xSize ) PRIVILEGED_FUNCTION;
void * pvPortCalloc( size_t xNum,
                     size_t xSize ) PRIVILEGED_FUNCTION;
void vPortFree( void * pv ) PRIVILEGED_FUNCTION;
void vPortInitialiseBlocks( void ) PRIVILEGED_FUNCTION;
size_t xPortGetFreeHeapSize( void ) PRIVILEGED_FUNCTION;
size_t xPortGetMinimumEverFreeHeapSize( void ) PRIVILEGED_FUNCTION;

#if ( configSTACK_ALLOCATION_FROM_SEPARATE_HEAP == 1 )
    void * pvPortMallocStack( size_t xSize ) PRIVILEGED_FUNCTION;
    void vPortFreeStack( void * pv ) PRIVILEGED_FUNCTION;
#else
    #define pvPortMallocStack    pvPortMalloc
    #define vPortFreeStack       vPortFree
#endif

#if ( configUSE_MALLOC_FAILED_HOOK == 1 )

/**
 * task.h
 * @code{c}
 * void vApplicationMallocFailedHook( void )
 * @endcode
 *
 * This hook function is called when allocation failed.
 */
    void vApplicationMallocFailedHook( void ); /*lint !e526 Symbol not defined as it is an application callback. */
#endif

/*
 * Setup the hardware ready for the scheduler to take control.  This generally
 * sets up a tick interrupt and sets timers for the correct tick frequency.
 */
BaseType_t xPortStartScheduler( void ) PRIVILEGED_FUNCTION;

/*
 * Undo any hardware/ISR setup that was performed by xPortStartScheduler() so
 * the hardware is left in its original condition after the scheduler stops
 * executing.
 */
void vPortEndScheduler( void ) PRIVILEGED_FUNCTION;

/*
 * The structures and methods of manipulating the MPU are contained within the
 * port layer.
 *
 * Fills the xMPUSettings structure with the memory region information
 * contained in xRegions.
 */
#if ( portUSING_MPU_WRAPPERS == 1 )
    struct xMEMORY_REGION;
    void vPortStoreTaskMPUSettings( xMPU_SETTINGS * xMPUSettings,
                                    const struct xMEMORY_REGION * const xRegions,
                                    StackType_t * pxBottomOfStack,
                                    configSTACK_DEPTH_TYPE uxStackDepth ) PRIVILEGED_FUNCTION;
#endif

/* *INDENT-OFF* */
#ifdef __cplusplus
    }
#endif
/* *INDENT-ON* */

#endif /* PORTABLE_H */


portable.h

/*
 * FreeRTOS Kernel V10.4.6
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
*/

#ifndef PORTMACRO_H
#define PORTMACRO_H

#ifdef __cplusplus
extern "C" {
#endif

/*-----------------------------------------------------------
 * Port specific definitions.
 *
 * The settings in this file configure FreeRTOS correctly for the
 * given hardware and compiler.
 *
 * These settings should not be altered.
 *-----------------------------------------------------------
 */

/* Type definitions. */

typedef uint8_t                     StackType_t;
typedef int8_t                      BaseType_t;
typedef uint8_t                     UBaseType_t;

#if configUSE_16_BIT_TICKS == 1
    typedef uint16_t                TickType_t;
    #define portMAX_DELAY           ( TickType_t ) 0xffff
#else
    typedef uint32_t                TickType_t;
    #define portMAX_DELAY           ( TickType_t ) 0xffffffffUL
#endif
/*-----------------------------------------------------------*/

/* Critical section management. */

#define portENTER_CRITICAL()        __asm__ __volatile__ (                          \
                                        "in __tmp_reg__, __SREG__"        "\n\t"    \
                                        "cli"                             "\n\t"    \
                                        "push __tmp_reg__"                "\n\t"    \
                                        ::: "memory"                                \
                                        )


#define portEXIT_CRITICAL()         __asm__ __volatile__ (                          \
                                        "pop __tmp_reg__"                 "\n\t"    \
                                        "out __SREG__, __tmp_reg__"       "\n\t"    \
                                        ::: "memory"                                \
                                        )


#define portDISABLE_INTERRUPTS()    __asm__ __volatile__ ( "cli" ::: "memory")
#define portENABLE_INTERRUPTS()     __asm__ __volatile__ ( "sei" ::: "memory")
/*-----------------------------------------------------------*/

/* Architecture specifics. */

#define sleep_reset()               do { _SLEEP_CONTROL_REG = 0; } while(0)     /* reset all sleep_mode() configurations. */

#define portSTACK_GROWTH            ( -1 )

/* Timing for the scheduler.
 * Watchdog Timer is 128kHz nominal,
 * but 120 kHz at 5V DC and 25 degrees is actually more accurate,
 * from data sheet.
 */
#if defined( portUSE_WDTO )
#define portTICK_PERIOD_MS          ( (TickType_t) _BV( portUSE_WDTO + 4 ) )
#else
#define portTICK_PERIOD_MS          ( (TickType_t) 1000 / configTICK_RATE_HZ )
#endif

#define portBYTE_ALIGNMENT          1
#define portNOP()                   __asm__ __volatile__ ( "nop" );
/*-----------------------------------------------------------*/

/* Kernel utilities. */

extern void vPortDelay( const uint32_t ms );
#define portDELAY( ms )             vPortDelay( ms )

extern void vPortYield( void ) __attribute__ ((naked));
#define portYIELD()                 vPortYield()

extern void vPortYieldFromISR( void ) __attribute__ ((naked));
#define portYIELD_FROM_ISR()        vPortYieldFromISR()
/*-----------------------------------------------------------*/

#if defined(__AVR_3_BYTE_PC__)
/* Task function macros as described on the FreeRTOS.org WEB site. */

/* Add .lowtext tag from the avr linker script avr6.x for ATmega2560 and ATmega2561
 * to make sure functions are loaded in low memory.
 */
#define portTASK_FUNCTION_PROTO( vFunction, pvParameters ) void vFunction( void *pvParameters ) __attribute__ ((section (".lowtext")))
#else
#define portTASK_FUNCTION_PROTO( vFunction, pvParameters ) void vFunction( void *pvParameters )
#endif

#define portTASK_FUNCTION( vFunction, pvParameters ) void vFunction( void *pvParameters )

#ifdef __cplusplus
}
#endif

#endif /* PORTMACRO_H */


portmacro.h

/*
 * FreeRTOS Kernel V10.4.6
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
 */

#ifndef PROJDEFS_H
#define PROJDEFS_H

/*
 * Defines the prototype to which task functions must conform.  Defined in this
 * file to ensure the type is known before portable.h is included.
 */
typedef void (* TaskFunction_t)( void * );

/* Converts a time in milliseconds to a time in ticks.  This macro can be
 * overridden by a macro of the same name defined in FreeRTOSConfig.h in case the
 * definition here is not suitable for your application. */
#ifndef pdMS_TO_TICKS
    #if configUSE_16_BIT_TICKS == 1
        #define pdMS_TO_TICKS( xTimeInMs )   ( ( TickType_t ) ( ( ( uint32_t ) ( xTimeInMs ) * ( TickType_t ) configTICK_RATE_HZ ) / ( TickType_t ) 1000U ) )
    #else
        #define pdMS_TO_TICKS( xTimeInMs )   ( ( TickType_t ) ( ( ( TickType_t ) ( xTimeInMs ) * ( TickType_t ) configTICK_RATE_HZ ) / ( TickType_t ) 1000U ) )
    #endif
#endif

#define pdFALSE                                  ( ( BaseType_t ) 0 )
#define pdTRUE                                   ( ( BaseType_t ) 1 )

#define pdPASS                                   ( pdTRUE )
#define pdFAIL                                   ( pdFALSE )
#define errQUEUE_EMPTY                           ( ( BaseType_t ) 0 )
#define errQUEUE_FULL                            ( ( BaseType_t ) 0 )

/* FreeRTOS error definitions. */
#define errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY    ( -1 )
#define errQUEUE_BLOCKED                         ( -4 )
#define errQUEUE_YIELD                           ( -5 )

/* Macros used for basic data corruption checks. */
#ifndef configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES
    #define configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES    0
#endif

#if ( configUSE_16_BIT_TICKS == 1 )
    #define pdINTEGRITY_CHECK_VALUE    0x5a5a
#else
    #define pdINTEGRITY_CHECK_VALUE    0x5a5a5a5aUL
#endif

#endif /* PROJDEFS_H */


projdefs.h

queue.c

queue.h

semphr.h

/*
 * FreeRTOS Kernel V10.4.6
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
 */

#ifndef STACK_MACROS_H
#define STACK_MACROS_H

/*
 * Call the stack overflow hook function if the stack of the task being swapped
 * out is currently overflowed, or looks like it might have overflowed in the
 * past.
 *
 * Setting configCHECK_FOR_STACK_OVERFLOW to 1 will cause the macro to check
 * the current stack state only - comparing the current top of stack value to
 * the stack limit.  Setting configCHECK_FOR_STACK_OVERFLOW to greater than 1
 * will also cause the last few stack bytes to be checked to ensure the value
 * to which the bytes were set when the task was created have not been
 * overwritten.  Note this second test does not guarantee that an overflowed
 * stack will always be recognised.
 */

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

/*
 * portSTACK_LIMIT_PADDING is a number of extra words to consider to be in
 * use on the stack.
 */
#ifndef portSTACK_LIMIT_PADDING
    #define portSTACK_LIMIT_PADDING    0
#endif

#if ( ( configCHECK_FOR_STACK_OVERFLOW == 1 ) && ( portSTACK_GROWTH < 0 ) )

/* Only the current stack state is to be checked. */
    #define taskCHECK_FOR_STACK_OVERFLOW()                                                            \
    {                                                                                                 \
        /* Is the currently saved stack pointer within the stack limit? */                            \
        if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack + portSTACK_LIMIT_PADDING )           \
        {                                                                                             \
            vApplicationStackOverflowHook( ( TaskHandle_t ) pxCurrentTCB, pxCurrentTCB->pcTaskName ); \
        }                                                                                             \
    }

#endif /* configCHECK_FOR_STACK_OVERFLOW == 1 */
/*-----------------------------------------------------------*/

#if ( ( configCHECK_FOR_STACK_OVERFLOW == 1 ) && ( portSTACK_GROWTH > 0 ) )

/* Only the current stack state is to be checked. */
    #define taskCHECK_FOR_STACK_OVERFLOW()                                                            \
    {                                                                                                 \
                                                                                                      \
        /* Is the currently saved stack pointer within the stack limit? */                            \
        if( pxCurrentTCB->pxTopOfStack >= pxCurrentTCB->pxEndOfStack - portSTACK_LIMIT_PADDING )      \
        {                                                                                             \
            vApplicationStackOverflowHook( ( TaskHandle_t ) pxCurrentTCB, pxCurrentTCB->pcTaskName ); \
        }                                                                                             \
    }

#endif /* configCHECK_FOR_STACK_OVERFLOW == 1 */
/*-----------------------------------------------------------*/

#if ( ( configCHECK_FOR_STACK_OVERFLOW > 1 ) && ( portSTACK_GROWTH < 0 ) )

    #define taskCHECK_FOR_STACK_OVERFLOW()                                                            \
    {                                                                                                 \
        const uint32_t * const pulStack = ( uint32_t * ) pxCurrentTCB->pxStack;                       \
        const uint32_t ulCheckValue = ( uint32_t ) 0xa5a5a5a5;                                        \
                                                                                                      \
        if( ( pulStack[ 0 ] != ulCheckValue ) ||                                                      \
            ( pulStack[ 1 ] != ulCheckValue ) ||                                                      \
            ( pulStack[ 2 ] != ulCheckValue ) ||                                                      \
            ( pulStack[ 3 ] != ulCheckValue ) )                                                       \
        {                                                                                             \
            vApplicationStackOverflowHook( ( TaskHandle_t ) pxCurrentTCB, pxCurrentTCB->pcTaskName ); \
        }                                                                                             \
    }

#endif /* #if( configCHECK_FOR_STACK_OVERFLOW > 1 ) */
/*-----------------------------------------------------------*/

#if ( ( configCHECK_FOR_STACK_OVERFLOW > 1 ) && ( portSTACK_GROWTH > 0 ) )

    #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                \
    {                                                                                                                                     \
        int8_t * pcEndOfStack = ( int8_t * ) pxCurrentTCB->pxEndOfStack;                                                                  \
        static const uint8_t ucExpectedStackBytes[] = { tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,   \
                                                        tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,   \
                                                        tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,   \
                                                        tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,   \
                                                        tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE }; \
                                                                                                                                          \
                                                                                                                                          \
        pcEndOfStack -= sizeof( ucExpectedStackBytes );                                                                                   \
                                                                                                                                          \
        /* Has the extremity of the task stack ever been written over? */                                                                 \
        if( memcmp( ( void * ) pcEndOfStack, ( void * ) ucExpectedStackBytes, sizeof( ucExpectedStackBytes ) ) != 0 )                     \
        {                                                                                                                                 \
            vApplicationStackOverflowHook( ( TaskHandle_t ) pxCurrentTCB, pxCurrentTCB->pcTaskName );                                     \
        }                                                                                                                                 \
    }

#endif /* #if( configCHECK_FOR_STACK_OVERFLOW > 1 ) */
/*-----------------------------------------------------------*/

/* Remove stack overflow macro if not being used. */
#ifndef taskCHECK_FOR_STACK_OVERFLOW
    #define taskCHECK_FOR_STACK_OVERFLOW()
#endif



#endif /* STACK_MACROS_H */


stack_macros.h

task.h

tasks.c

timers.c

timers.h

/*
 * Copyright (C) 2022 Phillip Stevens  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.
 *
 *
 * This file is NOT part of the FreeRTOS distribution.
 *
 */
#include <stdlib.h>

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>

#include <util/delay.h>

#include <Arduino.h>

/* FreeRTOS includes. */
#include "Arduino_FreeRTOS.h"
#include "task.h"
#include "timers.h"

extern void setup(void);
extern void loop(void);

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

void initVariant(void) __attribute__ ((OS_main));

void initVariant(void)
{
    // As the Task stacks are on heap before Task allocated heap variables,
    // the library default __malloc_heap_end = 0 doesn't work.
    __malloc_heap_end = (char *)(RAMEND - __malloc_margin);

#if defined(USBCON)
    USBDevice.attach();
#endif

    setup();                    // the normal Arduino setup() function is run here.
    vTaskStartScheduler();      // initialise and run the freeRTOS scheduler. Execution should never return here.
}


/*-----------------------------------------------------------*/
#if ( configUSE_IDLE_HOOK == 1 )
/*
 * Call the user defined loop() function from within the idle task.
 * This allows the application designer to add background functionality
 * without the overhead of a separate task.
 *
 * NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES, CALL A FUNCTION THAT MIGHT BLOCK.
 *
 */
void vApplicationIdleHook( void ) __attribute__ ((weak));

void vApplicationIdleHook( void )
{
    loop();                     // the normal Arduino loop() function is run here.
    if (serialEventRun) serialEventRun();
}

#else
    void loop() {} //Empty loop function
#endif /* configUSE_IDLE_HOOK == 1 */
/*-----------------------------------------------------------*/

#if ( configUSE_MALLOC_FAILED_HOOK == 1 || configCHECK_FOR_STACK_OVERFLOW >= 1 || configDEFAULT_ASSERT == 1 )

/**
 * Private function to enable board led to use it in application hooks
 */
void prvSetMainLedOn( void ) 
{

#if defined(__AVR_ATmega640__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2560__) || defined(__AVR_ATmega2561__) // Arduino Mega with 2560
    DDRB  |= _BV(DDB7);
    PORTB |= _BV(PORTB7);       // Main (red PB7) LED on. Main LED on.

#elif defined(__AVR_ATmega644P__) || defined(__AVR_ATmega644PA__) || defined(__AVR_ATmega1284P__) || defined(__AVR_ATmega1284PA__) // Seeed Goldilocks with 1284p
    DDRB  |= _BV(DDB7);
    PORTB |= _BV(PORTB7);       // Main (red PB7) LED on. Main LED on.

#elif defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) // assume we're using an Arduino Uno with 328p
    DDRB  |= _BV(DDB5);
    PORTB |= _BV(PORTB5);       // Main (red PB5) LED on. Main LED on.

#elif defined(__AVR_ATmega32U4__) || defined(__AVR_ATmega16U4__) // assume we're using an Arduino Leonardo with 32u4
    DDRC  |= _BV(DDC7);
    PORTC |= _BV(PORTC7);       // Main (red PC7) LED on. Main LED on.

#endif

}

/**
 * Private function to blink board led to use it in application hooks
 */
void prvBlinkMainLed( void ) 
{

#if defined(__AVR_ATmega640__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2560__) || defined(__AVR_ATmega2561__)  // Mega with 2560
        PINB  |= _BV(PINB7);       // Main (red PB7) LED toggle.

#elif defined(__AVR_ATmega644P__) || defined(__AVR_ATmega644PA__) || defined(__AVR_ATmega1284P__) || defined(__AVR_ATmega1284PA__) // Seeed Goldilocks with 1284p
        PINB  |= _BV(PINB7);       // Main (red PB7) LED toggle.

#elif defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) // assume we're using an Arduino Uno with 328p
        PINB  |= _BV(PINB5);       // Main (red PB5) LED toggle.

#elif defined(__AVR_ATmega32U4__) || defined(__AVR_ATmega16U4__) // assume we're using an Arduino Leonardo with 32u4
        PINC  |= _BV(PINC7);       // Main (red PC7) LED toggle.

#endif

}

#endif

#if ( configUSE_MALLOC_FAILED_HOOK == 1 )
/*---------------------------------------------------------------------------*\
Usage:
    called by task system when a malloc failure is noticed
Description:
    Malloc failure handler -- Shut down all interrupts, send serious complaint
    to command port. FAST Blink on main LED.
Arguments:
    pxTask - pointer to task handle
    pcTaskName - pointer to task name
Results:
    <none>
Notes:
    This routine will never return.
    This routine is referenced in the task.c file of FreeRTOS as an extern.
\*---------------------------------------------------------------------------*/
void vApplicationMallocFailedHook( void ) __attribute__ ((weak));

void vApplicationMallocFailedHook( void )
{
    prvSetMainLedOn(); // Main LED on.
    
    for(;;)
    {
        _delay_ms(50);
        prvBlinkMainLed(); // Main LED fast blink.
    }
}

#endif /* configUSE_MALLOC_FAILED_HOOK == 1 */
/*-----------------------------------------------------------*/


#if ( configCHECK_FOR_STACK_OVERFLOW >= 1 )

void vApplicationStackOverflowHook( TaskHandle_t xTask,
                                    char * pcTaskName ) __attribute__ ((weak));

void vApplicationStackOverflowHook( TaskHandle_t xTask __attribute__ ((unused)),
                                    char * pcTaskName __attribute__ ((unused)) )
{

    prvSetMainLedOn(); // Main LED on.

    for(;;)
    {
        _delay_ms(2000);
        prvBlinkMainLed();  // Main LED slow blink.
    }
}

#endif /* configCHECK_FOR_STACK_OVERFLOW >= 1 */
/*-----------------------------------------------------------*/

#if ( configSUPPORT_STATIC_ALLOCATION >= 1 )

void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
                                    StackType_t ** ppxIdleTaskStackBuffer,
                                    configSTACK_DEPTH_TYPE * puxIdleTaskStackSize ) __attribute__ ((weak));

void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
                                    StackType_t ** ppxIdleTaskStackBuffer,
                                    configSTACK_DEPTH_TYPE * puxIdleTaskStackSize )
{
    static StaticTask_t xIdleTaskTCB;
    static StackType_t uxIdleTaskStack[ configMINIMAL_STACK_SIZE ];

    *ppxIdleTaskTCBBuffer = &xIdleTaskTCB;
    *ppxIdleTaskStackBuffer = uxIdleTaskStack;
    *puxIdleTaskStackSize = configMINIMAL_STACK_SIZE;
}

#if ( configUSE_TIMERS >= 1 )

void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,
                                     StackType_t ** ppxTimerTaskStackBuffer,
                                     configSTACK_DEPTH_TYPE * puxTimerTaskStackSize ) __attribute__ ((weak));

void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,
                                     StackType_t ** ppxTimerTaskStackBuffer,
                                     configSTACK_DEPTH_TYPE * puxTimerTaskStackSize )
{
    static StaticTask_t xTimerTaskTCB;
    static StackType_t uxTimerTaskStack[ configTIMER_TASK_STACK_DEPTH ];

    *ppxTimerTaskTCBBuffer = &xTimerTaskTCB;
    *ppxTimerTaskStackBuffer = uxTimerTaskStack;
    *puxTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;
}

#endif /* configUSE_TIMERS >= 1 */

#endif /* configSUPPORT_STATIC_ALLOCATION >= 1 */

/**
 * configASSERT default implementation
 */
#if configDEFAULT_ASSERT == 1

void vApplicationAssertHook() {

    taskDISABLE_INTERRUPTS(); // Disable task interrupts

    prvSetMainLedOn(); // Main LED on.
    for(;;)
    {
        _delay_ms(100);
        prvBlinkMainLed(); // Led off.

        _delay_ms(2000);
        prvBlinkMainLed(); // Led on.

        _delay_ms(100);
        prvBlinkMainLed(); // Led off

        _delay_ms(100);
        prvBlinkMainLed(); // Led on.
    }
}
#endif
