新建项目

2023-04-29 09:09:12 +08:00
1 parent 5e2e890cfc
commit 633d9b872b
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+/*
+ * FreeRTOS Kernel V10.3.1
+ * 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.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+
+/*
+ * The simplest possible implementation of pvPortMalloc().  Note that this
+ * implementation does NOT allow allocated memory to be freed again.
+ *
+ * See heap_2.c, heap_3.c and heap_4.c for alternative implementations, and the
+ * memory management pages of http://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 "FreeRTOS.h"
+#include "task.h"
+
+#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
+
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 0 )
+	#error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 0
+#endif
+
+/* A few bytes might be lost to byte aligning the heap start address. */
+#define configADJUSTED_HEAP_SIZE	( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT )
+
+/* Allocate the memory for the heap. */
+#if( configAPPLICATION_ALLOCATED_HEAP == 1 )
+	/* The application writer has already defined the array used for the RTOS
+	heap - probably so it can be placed in a special segment or address. */
+	extern uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
+#else
+	static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
+#endif /* configAPPLICATION_ALLOCATED_HEAP */
+
+/* Index into the ucHeap array. */
+static size_t xNextFreeByte = ( size_t ) 0;
+
+/*-----------------------------------------------------------*/
+
+void *pvPortMalloc( size_t xWantedSize )
+{
+void *pvReturn = NULL;
+static uint8_t *pucAlignedHeap = NULL;
+
+	/* Ensure that blocks are always aligned to the required number of bytes. */
+	#if( portBYTE_ALIGNMENT != 1 )
+	{
+		if( xWantedSize & portBYTE_ALIGNMENT_MASK )
+		{
+			/* Byte alignment required. */
+			xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
+		}
+	}
+	#endif
+
+	vTaskSuspendAll();
+	{
+		if( pucAlignedHeap == NULL )
+		{
+			/* Ensure the heap starts on a correctly aligned boundary. */
+			pucAlignedHeap = ( uint8_t * ) ( ( ( portPOINTER_SIZE_TYPE ) &ucHeap[ portBYTE_ALIGNMENT ] ) & ( ~( ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) ) );
+		}
+
+		/* Check there is enough room left for the allocation. */
+		if( ( ( xNextFreeByte + xWantedSize ) < configADJUSTED_HEAP_SIZE ) &&
+			( ( xNextFreeByte + xWantedSize ) > xNextFreeByte )	)/* Check for overflow. */
+		{
+			/* Return the next free byte then increment the index past this
+			block. */
+			pvReturn = pucAlignedHeap + xNextFreeByte;
+			xNextFreeByte += xWantedSize;
+		}
+
+		traceMALLOC( pvReturn, xWantedSize );
+	}
+	( void ) xTaskResumeAll();
+
+	#if( configUSE_MALLOC_FAILED_HOOK == 1 )
+	{
+		if( pvReturn == NULL )
+		{
+			extern void vApplicationMallocFailedHook( void );
+			vApplicationMallocFailedHook();
+		}
+	}
+	#endif
+
+	return pvReturn;
+}
+/*-----------------------------------------------------------*/
+
+void vPortFree( void *pv )
+{
+	/* Memory cannot be freed using this scheme.  See heap_2.c, heap_3.c and
+	heap_4.c for alternative implementations, and the memory management pages of
+	http://www.FreeRTOS.org for more information. */
+	( void ) pv;
+
+	/* Force an assert as it is invalid to call this function. */
+	configASSERT( pv == NULL );
+}
+/*-----------------------------------------------------------*/
+
+void vPortInitialiseBlocks( void )
+{
+	/* Only required when static memory is not cleared. */
+	xNextFreeByte = ( size_t ) 0;
+}
+/*-----------------------------------------------------------*/
+
+size_t xPortGetFreeHeapSize( void )
+{
+	return ( configADJUSTED_HEAP_SIZE - xNextFreeByte );
+}
+
+
+
@@ -0,0 +1,272 @@
+/*
+ * FreeRTOS Kernel V10.3.1
+ * 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.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+/*
+ * A sample implementation of pvPortMalloc() and vPortFree() that permits
+ * allocated blocks to be freed, but does not combine adjacent free blocks
+ * into a single larger block (and so will fragment memory).  See heap_4.c for
+ * an equivalent that does combine adjacent blocks into single larger blocks.
+ *
+ * See heap_1.c, heap_3.c and heap_4.c for alternative implementations, and the
+ * memory management pages of http://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 "FreeRTOS.h"
+#include "task.h"
+
+#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
+
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 0 )
+	#error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 0
+#endif
+
+/* A few bytes might be lost to byte aligning the heap start address. */
+#define configADJUSTED_HEAP_SIZE	( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT )
+
+/*
+ * Initialises the heap structures before their first use.
+ */
+static void prvHeapInit( void );
+
+/* Allocate the memory for the heap. */
+#if( configAPPLICATION_ALLOCATED_HEAP == 1 )
+	/* The application writer has already defined the array used for the RTOS
+	heap - probably so it can be placed in a special segment or address. */
+	extern uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
+#else
+	static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
+#endif /* configAPPLICATION_ALLOCATED_HEAP */
+
+
+/* Define the linked list structure.  This is used to link free blocks in order
+of their size. */
+typedef struct A_BLOCK_LINK
+{
+	struct A_BLOCK_LINK *pxNextFreeBlock;	/*<< The next free block in the list. */
+	size_t xBlockSize;						/*<< The size of the free block. */
+} BlockLink_t;
+
+
+static const uint16_t heapSTRUCT_SIZE	= ( ( sizeof ( BlockLink_t ) + ( portBYTE_ALIGNMENT - 1 ) ) & ~portBYTE_ALIGNMENT_MASK );
+#define heapMINIMUM_BLOCK_SIZE	( ( size_t ) ( heapSTRUCT_SIZE * 2 ) )
+
+/* Create a couple of list links to mark the start and end of the list. */
+static BlockLink_t xStart, xEnd;
+
+/* Keeps track of the number of free bytes remaining, but says nothing about
+fragmentation. */
+static size_t xFreeBytesRemaining = configADJUSTED_HEAP_SIZE;
+
+/* STATIC FUNCTIONS ARE DEFINED AS MACROS TO MINIMIZE THE FUNCTION CALL DEPTH. */
+
+/*
+ * Insert a block into the list of free blocks - which is ordered by size of
+ * the block.  Small blocks at the start of the list and large blocks at the end
+ * of the list.
+ */
+#define prvInsertBlockIntoFreeList( pxBlockToInsert )								\
+{																					\
+BlockLink_t *pxIterator;															\
+size_t xBlockSize;																	\
+																					\
+	xBlockSize = pxBlockToInsert->xBlockSize;										\
+																					\
+	/* Iterate through the list until a block is found that has a larger size */	\
+	/* than the block we are inserting. */											\
+	for( pxIterator = &xStart; pxIterator->pxNextFreeBlock->xBlockSize < xBlockSize; pxIterator = pxIterator->pxNextFreeBlock )	\
+	{																				\
+		/* There is nothing to do here - just iterate to the correct position. */	\
+	}																				\
+																					\
+	/* Update the list to include the block being inserted in the correct */		\
+	/* position. */																	\
+	pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock;					\
+	pxIterator->pxNextFreeBlock = pxBlockToInsert;									\
+}
+/*-----------------------------------------------------------*/
+
+void *pvPortMalloc( size_t xWantedSize )
+{
+BlockLink_t *pxBlock, *pxPreviousBlock, *pxNewBlockLink;
+static BaseType_t xHeapHasBeenInitialised = pdFALSE;
+void *pvReturn = NULL;
+
+	vTaskSuspendAll();
+	{
+		/* If this is the first call to malloc then the heap will require
+		initialisation to setup the list of free blocks. */
+		if( xHeapHasBeenInitialised == pdFALSE )
+		{
+			prvHeapInit();
+			xHeapHasBeenInitialised = pdTRUE;
+		}
+
+		/* The wanted size is increased so it can contain a BlockLink_t
+		structure in addition to the requested amount of bytes. */
+		if( xWantedSize > 0 )
+		{
+			xWantedSize += heapSTRUCT_SIZE;
+
+			/* Ensure that blocks are always aligned to the required number of bytes. */
+			if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0 )
+			{
+				/* Byte alignment required. */
+				xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
+			}
+		}
+
+		if( ( xWantedSize > 0 ) && ( xWantedSize < configADJUSTED_HEAP_SIZE ) )
+		{
+			/* Blocks are stored in byte order - traverse the list from the start
+			(smallest) block until one of adequate size is found. */
+			pxPreviousBlock = &xStart;
+			pxBlock = xStart.pxNextFreeBlock;
+			while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) )
+			{
+				pxPreviousBlock = pxBlock;
+				pxBlock = pxBlock->pxNextFreeBlock;
+			}
+
+			/* If we found the end marker then a block of adequate size was not found. */
+			if( pxBlock != &xEnd )
+			{
+				/* Return the memory space - jumping over the BlockLink_t structure
+				at its start. */
+				pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock->pxNextFreeBlock ) + heapSTRUCT_SIZE );
+
+				/* This block is being returned for use so must be taken out of the
+				list of free blocks. */
+				pxPreviousBlock->pxNextFreeBlock = pxBlock->pxNextFreeBlock;
+
+				/* If the block is larger than required it can be split into two. */
+				if( ( pxBlock->xBlockSize - xWantedSize ) > heapMINIMUM_BLOCK_SIZE )
+				{
+					/* This block is to be split into two.  Create a new block
+					following the number of bytes requested. The void cast is
+					used to prevent byte alignment warnings from the compiler. */
+					pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize );
+
+					/* Calculate the sizes of two blocks split from the single
+					block. */
+					pxNewBlockLink->xBlockSize = pxBlock->xBlockSize - xWantedSize;
+					pxBlock->xBlockSize = xWantedSize;
+
+					/* Insert the new block into the list of free blocks. */
+					prvInsertBlockIntoFreeList( ( pxNewBlockLink ) );
+				}
+
+				xFreeBytesRemaining -= pxBlock->xBlockSize;
+			}
+		}
+
+		traceMALLOC( pvReturn, xWantedSize );
+	}
+	( void ) xTaskResumeAll();
+
+	#if( configUSE_MALLOC_FAILED_HOOK == 1 )
+	{
+		if( pvReturn == NULL )
+		{
+			extern void vApplicationMallocFailedHook( void );
+			vApplicationMallocFailedHook();
+		}
+	}
+	#endif
+
+	return pvReturn;
+}
+/*-----------------------------------------------------------*/
+
+void vPortFree( void *pv )
+{
+uint8_t *puc = ( uint8_t * ) pv;
+BlockLink_t *pxLink;
+
+	if( pv != NULL )
+	{
+		/* The memory being freed will have an BlockLink_t structure immediately
+		before it. */
+		puc -= heapSTRUCT_SIZE;
+
+		/* This unexpected casting is to keep some compilers from issuing
+		byte alignment warnings. */
+		pxLink = ( void * ) puc;
+
+		vTaskSuspendAll();
+		{
+			/* Add this block to the list of free blocks. */
+			prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) );
+			xFreeBytesRemaining += pxLink->xBlockSize;
+			traceFREE( pv, pxLink->xBlockSize );
+		}
+		( void ) xTaskResumeAll();
+	}
+}
+/*-----------------------------------------------------------*/
+
+size_t xPortGetFreeHeapSize( void )
+{
+	return xFreeBytesRemaining;
+}
+/*-----------------------------------------------------------*/
+
+void vPortInitialiseBlocks( void )
+{
+	/* This just exists to keep the linker quiet. */
+}
+/*-----------------------------------------------------------*/
+
+static void prvHeapInit( void )
+{
+BlockLink_t *pxFirstFreeBlock;
+uint8_t *pucAlignedHeap;
+
+	/* Ensure the heap starts on a correctly aligned boundary. */
+	pucAlignedHeap = ( uint8_t * ) ( ( ( portPOINTER_SIZE_TYPE ) &ucHeap[ portBYTE_ALIGNMENT ] ) & ( ~( ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) ) );
+
+	/* xStart is used to hold a pointer to the first item in the list of free
+	blocks.  The void cast is used to prevent compiler warnings. */
+	xStart.pxNextFreeBlock = ( void * ) pucAlignedHeap;
+	xStart.xBlockSize = ( size_t ) 0;
+
+	/* xEnd is used to mark the end of the list of free blocks. */
+	xEnd.xBlockSize = configADJUSTED_HEAP_SIZE;
+	xEnd.pxNextFreeBlock = NULL;
+
+	/* To start with there is a single free block that is sized to take up the
+	entire heap space. */
+	pxFirstFreeBlock = ( void * ) pucAlignedHeap;
+	pxFirstFreeBlock->xBlockSize = configADJUSTED_HEAP_SIZE;
+	pxFirstFreeBlock->pxNextFreeBlock = &xEnd;
+}
+/*-----------------------------------------------------------*/
@@ -0,0 +1,97 @@
+/*
+ * FreeRTOS Kernel V10.3.1
+ * 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.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+
+/*
+ * 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 http://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 "FreeRTOS.h"
+#include "task.h"
+
+#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
+
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 0 )
+	#error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 0
+#endif
+
+/*-----------------------------------------------------------*/
+
+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 )
+		{
+			extern void vApplicationMallocFailedHook( void );
+			vApplicationMallocFailedHook();
+		}
+	}
+	#endif
+
+	return pvReturn;
+}
+/*-----------------------------------------------------------*/
+
+void vPortFree( void *pv )
+{
+	if( pv )
+	{
+		vTaskSuspendAll();
+		{
+			free( pv );
+			traceFREE( pv, 0 );
+		}
+		( void ) xTaskResumeAll();
+	}
+}
+
+
+
@@ -0,0 +1,492 @@
+/*
+ * FreeRTOS Kernel V10.3.1
+ * 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.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+/*
+ * A sample implementation of pvPortMalloc() and vPortFree() that combines
+ * (coalescences) adjacent memory blocks as they are freed, and in so doing
+ * limits memory fragmentation.
+ *
+ * See heap_1.c, heap_2.c and heap_3.c for alternative implementations, and the
+ * memory management pages of http://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 "FreeRTOS.h"
+#include "task.h"
+
+#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
+
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 0 )
+	#error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 0
+#endif
+
+/* Block sizes must not get too small. */
+#define heapMINIMUM_BLOCK_SIZE	( ( size_t ) ( xHeapStructSize << 1 ) )
+
+/* Assumes 8bit bytes! */
+#define heapBITS_PER_BYTE		( ( size_t ) 8 )
+
+/* Allocate the memory for the heap. */
+#if( configAPPLICATION_ALLOCATED_HEAP == 1 )
+	/* The application writer has already defined the array used for the RTOS
+	heap - probably so it can be placed in a special segment or address. */
+	extern uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
+#else
+	static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
+#endif /* configAPPLICATION_ALLOCATED_HEAP */
+
+/* Define the linked list structure.  This is used to link free blocks in order
+of their memory address. */
+typedef struct A_BLOCK_LINK
+{
+	struct A_BLOCK_LINK *pxNextFreeBlock;	/*<< The next free block in the list. */
+	size_t xBlockSize;						/*<< The size of the free block. */
+} BlockLink_t;
+
+/*-----------------------------------------------------------*/
+
+/*
+ * Inserts a block of memory that is being freed into the correct position in
+ * the list of free memory blocks.  The block being freed will be merged with
+ * the block in front it and/or the block behind it if the memory blocks are
+ * adjacent to each other.
+ */
+static void prvInsertBlockIntoFreeList( BlockLink_t *pxBlockToInsert );
+
+/*
+ * Called automatically to setup the required heap structures the first time
+ * pvPortMalloc() is called.
+ */
+static void prvHeapInit( void );
+
+/*-----------------------------------------------------------*/
+
+/* The size of the structure placed at the beginning of each allocated memory
+block must by correctly byte aligned. */
+static const size_t xHeapStructSize	= ( sizeof( BlockLink_t ) + ( ( size_t ) ( portBYTE_ALIGNMENT - 1 ) ) ) & ~( ( size_t ) portBYTE_ALIGNMENT_MASK );
+
+/* Create a couple of list links to mark the start and end of the list. */
+static BlockLink_t xStart, *pxEnd = NULL;
+
+/* Keeps track of the number of calls to allocate and free memory as well as the
+number of free bytes remaining, but says nothing about fragmentation. */
+static size_t xFreeBytesRemaining = 0U;
+static size_t xMinimumEverFreeBytesRemaining = 0U;
+static size_t xNumberOfSuccessfulAllocations = 0;
+static size_t xNumberOfSuccessfulFrees = 0;
+
+/* Gets set to the top bit of an size_t type.  When this bit in the xBlockSize
+member of an BlockLink_t structure is set then the block belongs to the
+application.  When the bit is free the block is still part of the free heap
+space. */
+static size_t xBlockAllocatedBit = 0;
+
+/*-----------------------------------------------------------*/
+
+void *pvPortMalloc( size_t xWantedSize )
+{
+BlockLink_t *pxBlock, *pxPreviousBlock, *pxNewBlockLink;
+void *pvReturn = NULL;
+
+	vTaskSuspendAll();
+	{
+		/* If this is the first call to malloc then the heap will require
+		initialisation to setup the list of free blocks. */
+		if( pxEnd == NULL )
+		{
+			prvHeapInit();
+		}
+		else
+		{
+			mtCOVERAGE_TEST_MARKER();
+		}
+
+		/* Check the requested block size is not so large that the top bit is
+		set.  The top bit of the block size member of the BlockLink_t structure
+		is used to determine who owns the block - the application or the
+		kernel, so it must be free. */
+		if( ( xWantedSize & xBlockAllocatedBit ) == 0 )
+		{
+			/* The wanted size is increased so it can contain a BlockLink_t
+			structure in addition to the requested amount of bytes. */
+			if( xWantedSize > 0 )
+			{
+				xWantedSize += xHeapStructSize;
+
+				/* Ensure that blocks are always aligned to the required number
+				of bytes. */
+				if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
+				{
+					/* Byte alignment required. */
+					xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
+					configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
+				}
+				else
+				{
+					mtCOVERAGE_TEST_MARKER();
+				}
+			}
+			else
+			{
+				mtCOVERAGE_TEST_MARKER();
+			}
+
+			if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
+			{
+				/* Traverse the list from the start	(lowest address) block until
+				one	of adequate size is found. */
+				pxPreviousBlock = &xStart;
+				pxBlock = xStart.pxNextFreeBlock;
+				while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) )
+				{
+					pxPreviousBlock = pxBlock;
+					pxBlock = pxBlock->pxNextFreeBlock;
+				}
+
+				/* If the end marker was reached then a block of adequate size
+				was	not found. */
+				if( pxBlock != pxEnd )
+				{
+					/* Return the memory space pointed to - jumping over the
+					BlockLink_t structure at its start. */
+					pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock->pxNextFreeBlock ) + xHeapStructSize );
+
+					/* This block is being returned for use so must be taken out
+					of the list of free blocks. */
+					pxPreviousBlock->pxNextFreeBlock = pxBlock->pxNextFreeBlock;
+
+					/* If the block is larger than required it can be split into
+					two. */
+					if( ( pxBlock->xBlockSize - xWantedSize ) > heapMINIMUM_BLOCK_SIZE )
+					{
+						/* This block is to be split into two.  Create a new
+						block following the number of bytes requested. The void
+						cast is used to prevent byte alignment warnings from the
+						compiler. */
+						pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize );
+						configASSERT( ( ( ( size_t ) pxNewBlockLink ) & portBYTE_ALIGNMENT_MASK ) == 0 );
+
+						/* Calculate the sizes of two blocks split from the
+						single block. */
+						pxNewBlockLink->xBlockSize = pxBlock->xBlockSize - xWantedSize;
+						pxBlock->xBlockSize = xWantedSize;
+
+						/* Insert the new block into the list of free blocks. */
+						prvInsertBlockIntoFreeList( pxNewBlockLink );
+					}
+					else
+					{
+						mtCOVERAGE_TEST_MARKER();
+					}
+
+					xFreeBytesRemaining -= pxBlock->xBlockSize;
+
+					if( xFreeBytesRemaining < xMinimumEverFreeBytesRemaining )
+					{
+						xMinimumEverFreeBytesRemaining = xFreeBytesRemaining;
+					}
+					else
+					{
+						mtCOVERAGE_TEST_MARKER();
+					}
+
+					/* The block is being returned - it is allocated and owned
+					by the application and has no "next" block. */
+					pxBlock->xBlockSize |= xBlockAllocatedBit;
+					pxBlock->pxNextFreeBlock = NULL;
+					xNumberOfSuccessfulAllocations++;
+				}
+				else
+				{
+					mtCOVERAGE_TEST_MARKER();
+				}
+			}
+			else
+			{
+				mtCOVERAGE_TEST_MARKER();
+			}
+		}
+		else
+		{
+			mtCOVERAGE_TEST_MARKER();
+		}
+
+		traceMALLOC( pvReturn, xWantedSize );
+	}
+	( void ) xTaskResumeAll();
+
+	#if( configUSE_MALLOC_FAILED_HOOK == 1 )
+	{
+		if( pvReturn == NULL )
+		{
+			extern void vApplicationMallocFailedHook( void );
+			vApplicationMallocFailedHook();
+		}
+		else
+		{
+			mtCOVERAGE_TEST_MARKER();
+		}
+	}
+	#endif
+
+	configASSERT( ( ( ( size_t ) pvReturn ) & ( size_t ) portBYTE_ALIGNMENT_MASK ) == 0 );
+	return pvReturn;
+}
+/*-----------------------------------------------------------*/
+
+void vPortFree( void *pv )
+{
+uint8_t *puc = ( uint8_t * ) pv;
+BlockLink_t *pxLink;
+
+	if( pv != NULL )
+	{
+		/* The memory being freed will have an BlockLink_t structure immediately
+		before it. */
+		puc -= xHeapStructSize;
+
+		/* This casting is to keep the compiler from issuing warnings. */
+		pxLink = ( void * ) puc;
+
+		/* Check the block is actually allocated. */
+		configASSERT( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 );
+		configASSERT( pxLink->pxNextFreeBlock == NULL );
+
+		if( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 )
+		{
+			if( pxLink->pxNextFreeBlock == NULL )
+			{
+				/* The block is being returned to the heap - it is no longer
+				allocated. */
+				pxLink->xBlockSize &= ~xBlockAllocatedBit;
+
+				vTaskSuspendAll();
+				{
+					/* Add this block to the list of free blocks. */
+					xFreeBytesRemaining += pxLink->xBlockSize;
+					traceFREE( pv, pxLink->xBlockSize );
+					prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) );
+					xNumberOfSuccessfulFrees++;
+				}
+				( void ) xTaskResumeAll();
+			}
+			else
+			{
+				mtCOVERAGE_TEST_MARKER();
+			}
+		}
+		else
+		{
+			mtCOVERAGE_TEST_MARKER();
+		}
+	}
+}
+/*-----------------------------------------------------------*/
+
+size_t xPortGetFreeHeapSize( void )
+{
+	return xFreeBytesRemaining;
+}
+/*-----------------------------------------------------------*/
+
+size_t xPortGetMinimumEverFreeHeapSize( void )
+{
+	return xMinimumEverFreeBytesRemaining;
+}
+/*-----------------------------------------------------------*/
+
+void vPortInitialiseBlocks( void )
+{
+	/* This just exists to keep the linker quiet. */
+}
+/*-----------------------------------------------------------*/
+
+static void prvHeapInit( void )
+{
+BlockLink_t *pxFirstFreeBlock;
+uint8_t *pucAlignedHeap;
+size_t uxAddress;
+size_t xTotalHeapSize = configTOTAL_HEAP_SIZE;
+
+	/* Ensure the heap starts on a correctly aligned boundary. */
+	uxAddress = ( size_t ) ucHeap;
+
+	if( ( uxAddress & portBYTE_ALIGNMENT_MASK ) != 0 )
+	{
+		uxAddress += ( portBYTE_ALIGNMENT - 1 );
+		uxAddress &= ~( ( size_t ) portBYTE_ALIGNMENT_MASK );
+		xTotalHeapSize -= uxAddress - ( size_t ) ucHeap;
+	}
+
+	pucAlignedHeap = ( uint8_t * ) uxAddress;
+
+	/* xStart is used to hold a pointer to the first item in the list of free
+	blocks.  The void cast is used to prevent compiler warnings. */
+	xStart.pxNextFreeBlock = ( void * ) pucAlignedHeap;
+	xStart.xBlockSize = ( size_t ) 0;
+
+	/* pxEnd is used to mark the end of the list of free blocks and is inserted
+	at the end of the heap space. */
+	uxAddress = ( ( size_t ) pucAlignedHeap ) + xTotalHeapSize;
+	uxAddress -= xHeapStructSize;
+	uxAddress &= ~( ( size_t ) portBYTE_ALIGNMENT_MASK );
+	pxEnd = ( void * ) uxAddress;
+	pxEnd->xBlockSize = 0;
+	pxEnd->pxNextFreeBlock = NULL;
+
+	/* To start with there is a single free block that is sized to take up the
+	entire heap space, minus the space taken by pxEnd. */
+	pxFirstFreeBlock = ( void * ) pucAlignedHeap;
+	pxFirstFreeBlock->xBlockSize = uxAddress - ( size_t ) pxFirstFreeBlock;
+	pxFirstFreeBlock->pxNextFreeBlock = pxEnd;
+
+	/* Only one block exists - and it covers the entire usable heap space. */
+	xMinimumEverFreeBytesRemaining = pxFirstFreeBlock->xBlockSize;
+	xFreeBytesRemaining = pxFirstFreeBlock->xBlockSize;
+
+	/* Work out the position of the top bit in a size_t variable. */
+	xBlockAllocatedBit = ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 );
+}
+/*-----------------------------------------------------------*/
+
+static void prvInsertBlockIntoFreeList( BlockLink_t *pxBlockToInsert )
+{
+BlockLink_t *pxIterator;
+uint8_t *puc;
+
+	/* Iterate through the list until a block is found that has a higher address
+	than the block being inserted. */
+	for( pxIterator = &xStart; pxIterator->pxNextFreeBlock < pxBlockToInsert; pxIterator = pxIterator->pxNextFreeBlock )
+	{
+		/* Nothing to do here, just iterate to the right position. */
+	}
+
+	/* Do the block being inserted, and the block it is being inserted after
+	make a contiguous block of memory? */
+	puc = ( uint8_t * ) pxIterator;
+	if( ( puc + pxIterator->xBlockSize ) == ( uint8_t * ) pxBlockToInsert )
+	{
+		pxIterator->xBlockSize += pxBlockToInsert->xBlockSize;
+		pxBlockToInsert = pxIterator;
+	}
+	else
+	{
+		mtCOVERAGE_TEST_MARKER();
+	}
+
+	/* Do the block being inserted, and the block it is being inserted before
+	make a contiguous block of memory? */
+	puc = ( uint8_t * ) pxBlockToInsert;
+	if( ( puc + pxBlockToInsert->xBlockSize ) == ( uint8_t * ) pxIterator->pxNextFreeBlock )
+	{
+		if( pxIterator->pxNextFreeBlock != pxEnd )
+		{
+			/* Form one big block from the two blocks. */
+			pxBlockToInsert->xBlockSize += pxIterator->pxNextFreeBlock->xBlockSize;
+			pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock->pxNextFreeBlock;
+		}
+		else
+		{
+			pxBlockToInsert->pxNextFreeBlock = pxEnd;
+		}
+	}
+	else
+	{
+		pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock;
+	}
+
+	/* If the block being inserted plugged a gab, so was merged with the block
+	before and the block after, then it's pxNextFreeBlock pointer will have
+	already been set, and should not be set here as that would make it point
+	to itself. */
+	if( pxIterator != pxBlockToInsert )
+	{
+		pxIterator->pxNextFreeBlock = pxBlockToInsert;
+	}
+	else
+	{
+		mtCOVERAGE_TEST_MARKER();
+	}
+}
+/*-----------------------------------------------------------*/
+
+void vPortGetHeapStats( HeapStats_t *pxHeapStats )
+{
+BlockLink_t *pxBlock;
+size_t xBlocks = 0, xMaxSize = 0, xMinSize = portMAX_DELAY; /* portMAX_DELAY used as a portable way of getting the maximum value. */
+
+	vTaskSuspendAll();
+	{
+		pxBlock = xStart.pxNextFreeBlock;
+
+		/* pxBlock will be NULL if the heap has not been initialised.  The heap
+		is initialised automatically when the first allocation is made. */
+		if( pxBlock != NULL )
+		{
+			do
+			{
+				/* Increment the number of blocks and record the largest block seen
+				so far. */
+				xBlocks++;
+
+				if( pxBlock->xBlockSize > xMaxSize )
+				{
+					xMaxSize = pxBlock->xBlockSize;
+				}
+
+				if( pxBlock->xBlockSize < xMinSize )
+				{
+					xMinSize = pxBlock->xBlockSize;
+				}
+
+				/* Move to the next block in the chain until the last block is
+				reached. */
+				pxBlock = pxBlock->pxNextFreeBlock;
+			} while( pxBlock != pxEnd );
+		}
+	}
+	xTaskResumeAll();
+
+	pxHeapStats->xSizeOfLargestFreeBlockInBytes = xMaxSize;
+	pxHeapStats->xSizeOfSmallestFreeBlockInBytes = xMinSize;
+	pxHeapStats->xNumberOfFreeBlocks = xBlocks;
+
+	taskENTER_CRITICAL();
+	{
+		pxHeapStats->xAvailableHeapSpaceInBytes = xFreeBytesRemaining;
+		pxHeapStats->xNumberOfSuccessfulAllocations = xNumberOfSuccessfulAllocations;
+		pxHeapStats->xNumberOfSuccessfulFrees = xNumberOfSuccessfulFrees;
+		pxHeapStats->xMinimumEverFreeBytesRemaining = xMinimumEverFreeBytesRemaining;
+	}
+	taskEXIT_CRITICAL();
+}
+
@@ -0,0 +1,547 @@
+/*
+ * FreeRTOS Kernel V10.3.1
+ * 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.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+/*
+ * A sample implementation of pvPortMalloc() that allows the heap to be defined
+ * across multiple non-contigous blocks and combines (coalescences) adjacent
+ * memory blocks as they are freed.
+ *
+ * See heap_1.c, heap_2.c, heap_3.c and heap_4.c for alternative
+ * implementations, and the memory management pages of http://www.FreeRTOS.org
+ * for more information.
+ *
+ * Usage notes:
+ *
+ * vPortDefineHeapRegions() ***must*** be called before pvPortMalloc().
+ * pvPortMalloc() will be called if any task objects (tasks, queues, event
+ * groups, etc.) are created, therefore vPortDefineHeapRegions() ***must*** be
+ * called before any other objects are defined.
+ *
+ * vPortDefineHeapRegions() takes a single parameter.  The parameter is an array
+ * of HeapRegion_t structures.  HeapRegion_t is defined in portable.h as
+ *
+ * typedef struct HeapRegion
+ * {
+ *	uint8_t *pucStartAddress; << Start address of a block of memory that will be part of the heap.
+ *	size_t xSizeInBytes;	  << Size of the block of memory.
+ * } HeapRegion_t;
+ *
+ * The array is terminated using a NULL zero sized region definition, and the
+ * memory regions defined in the array ***must*** appear in address order from
+ * low address to high address.  So the following is a valid example of how
+ * to use the function.
+ *
+ * HeapRegion_t xHeapRegions[] =
+ * {
+ * 	{ ( uint8_t * ) 0x80000000UL, 0x10000 }, << Defines a block of 0x10000 bytes starting at address 0x80000000
+ * 	{ ( uint8_t * ) 0x90000000UL, 0xa0000 }, << Defines a block of 0xa0000 bytes starting at address of 0x90000000
+ * 	{ NULL, 0 }                << Terminates the array.
+ * };
+ *
+ * vPortDefineHeapRegions( xHeapRegions ); << Pass the array into vPortDefineHeapRegions().
+ *
+ * Note 0x80000000 is the lower address so appears in the array first.
+ *
+ */
+#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 "FreeRTOS.h"
+#include "task.h"
+
+#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
+
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 0 )
+	#error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 0
+#endif
+
+/* Block sizes must not get too small. */
+#define heapMINIMUM_BLOCK_SIZE	( ( size_t ) ( xHeapStructSize << 1 ) )
+
+/* Assumes 8bit bytes! */
+#define heapBITS_PER_BYTE		( ( size_t ) 8 )
+
+/* Define the linked list structure.  This is used to link free blocks in order
+of their memory address. */
+typedef struct A_BLOCK_LINK
+{
+	struct A_BLOCK_LINK *pxNextFreeBlock;	/*<< The next free block in the list. */
+	size_t xBlockSize;						/*<< The size of the free block. */
+} BlockLink_t;
+
+/*-----------------------------------------------------------*/
+
+/*
+ * Inserts a block of memory that is being freed into the correct position in
+ * the list of free memory blocks.  The block being freed will be merged with
+ * the block in front it and/or the block behind it if the memory blocks are
+ * adjacent to each other.
+ */
+static void prvInsertBlockIntoFreeList( BlockLink_t *pxBlockToInsert );
+
+/*-----------------------------------------------------------*/
+
+/* The size of the structure placed at the beginning of each allocated memory
+block must by correctly byte aligned. */
+static const size_t xHeapStructSize	= ( sizeof( BlockLink_t ) + ( ( size_t ) ( portBYTE_ALIGNMENT - 1 ) ) ) & ~( ( size_t ) portBYTE_ALIGNMENT_MASK );
+
+/* Create a couple of list links to mark the start and end of the list. */
+static BlockLink_t xStart, *pxEnd = NULL;
+
+/* Keeps track of the number of calls to allocate and free memory as well as the
+number of free bytes remaining, but says nothing about fragmentation. */
+static size_t xFreeBytesRemaining = 0U;
+static size_t xMinimumEverFreeBytesRemaining = 0U;
+static size_t xNumberOfSuccessfulAllocations = 0;
+static size_t xNumberOfSuccessfulFrees = 0;
+
+/* Gets set to the top bit of an size_t type.  When this bit in the xBlockSize
+member of an BlockLink_t structure is set then the block belongs to the
+application.  When the bit is free the block is still part of the free heap
+space. */
+static size_t xBlockAllocatedBit = 0;
+
+/*-----------------------------------------------------------*/
+
+void *pvPortMalloc( size_t xWantedSize )
+{
+BlockLink_t *pxBlock, *pxPreviousBlock, *pxNewBlockLink;
+void *pvReturn = NULL;
+
+	/* The heap must be initialised before the first call to
+	prvPortMalloc(). */
+	configASSERT( pxEnd );
+
+	vTaskSuspendAll();
+	{
+		/* Check the requested block size is not so large that the top bit is
+		set.  The top bit of the block size member of the BlockLink_t structure
+		is used to determine who owns the block - the application or the
+		kernel, so it must be free. */
+		if( ( xWantedSize & xBlockAllocatedBit ) == 0 )
+		{
+			/* The wanted size is increased so it can contain a BlockLink_t
+			structure in addition to the requested amount of bytes. */
+			if( xWantedSize > 0 )
+			{
+				xWantedSize += xHeapStructSize;
+
+				/* Ensure that blocks are always aligned to the required number
+				of bytes. */
+				if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
+				{
+					/* Byte alignment required. */
+					xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
+				}
+				else
+				{
+					mtCOVERAGE_TEST_MARKER();
+				}
+			}
+			else
+			{
+				mtCOVERAGE_TEST_MARKER();
+			}
+
+			if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
+			{
+				/* Traverse the list from the start	(lowest address) block until
+				one	of adequate size is found. */
+				pxPreviousBlock = &xStart;
+				pxBlock = xStart.pxNextFreeBlock;
+				while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) )
+				{
+					pxPreviousBlock = pxBlock;
+					pxBlock = pxBlock->pxNextFreeBlock;
+				}
+
+				/* If the end marker was reached then a block of adequate size
+				was	not found. */
+				if( pxBlock != pxEnd )
+				{
+					/* Return the memory space pointed to - jumping over the
+					BlockLink_t structure at its start. */
+					pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock->pxNextFreeBlock ) + xHeapStructSize );
+
+					/* This block is being returned for use so must be taken out
+					of the list of free blocks. */
+					pxPreviousBlock->pxNextFreeBlock = pxBlock->pxNextFreeBlock;
+
+					/* If the block is larger than required it can be split into
+					two. */
+					if( ( pxBlock->xBlockSize - xWantedSize ) > heapMINIMUM_BLOCK_SIZE )
+					{
+						/* This block is to be split into two.  Create a new
+						block following the number of bytes requested. The void
+						cast is used to prevent byte alignment warnings from the
+						compiler. */
+						pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize );
+
+						/* Calculate the sizes of two blocks split from the
+						single block. */
+						pxNewBlockLink->xBlockSize = pxBlock->xBlockSize - xWantedSize;
+						pxBlock->xBlockSize = xWantedSize;
+
+						/* Insert the new block into the list of free blocks. */
+						prvInsertBlockIntoFreeList( ( pxNewBlockLink ) );
+					}
+					else
+					{
+						mtCOVERAGE_TEST_MARKER();
+					}
+
+					xFreeBytesRemaining -= pxBlock->xBlockSize;
+
+					if( xFreeBytesRemaining < xMinimumEverFreeBytesRemaining )
+					{
+						xMinimumEverFreeBytesRemaining = xFreeBytesRemaining;
+					}
+					else
+					{
+						mtCOVERAGE_TEST_MARKER();
+					}
+
+					/* The block is being returned - it is allocated and owned
+					by the application and has no "next" block. */
+					pxBlock->xBlockSize |= xBlockAllocatedBit;
+					pxBlock->pxNextFreeBlock = NULL;
+					xNumberOfSuccessfulAllocations++;
+				}
+				else
+				{
+					mtCOVERAGE_TEST_MARKER();
+				}
+			}
+			else
+			{
+				mtCOVERAGE_TEST_MARKER();
+			}
+		}
+		else
+		{
+			mtCOVERAGE_TEST_MARKER();
+		}
+
+		traceMALLOC( pvReturn, xWantedSize );
+	}
+	( void ) xTaskResumeAll();
+
+	#if( configUSE_MALLOC_FAILED_HOOK == 1 )
+	{
+		if( pvReturn == NULL )
+		{
+			extern void vApplicationMallocFailedHook( void );
+			vApplicationMallocFailedHook();
+		}
+		else
+		{
+			mtCOVERAGE_TEST_MARKER();
+		}
+	}
+	#endif
+
+	return pvReturn;
+}
+/*-----------------------------------------------------------*/
+
+void vPortFree( void *pv )
+{
+uint8_t *puc = ( uint8_t * ) pv;
+BlockLink_t *pxLink;
+
+	if( pv != NULL )
+	{
+		/* The memory being freed will have an BlockLink_t structure immediately
+		before it. */
+		puc -= xHeapStructSize;
+
+		/* This casting is to keep the compiler from issuing warnings. */
+		pxLink = ( void * ) puc;
+
+		/* Check the block is actually allocated. */
+		configASSERT( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 );
+		configASSERT( pxLink->pxNextFreeBlock == NULL );
+
+		if( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 )
+		{
+			if( pxLink->pxNextFreeBlock == NULL )
+			{
+				/* The block is being returned to the heap - it is no longer
+				allocated. */
+				pxLink->xBlockSize &= ~xBlockAllocatedBit;
+
+				vTaskSuspendAll();
+				{
+					/* Add this block to the list of free blocks. */
+					xFreeBytesRemaining += pxLink->xBlockSize;
+					traceFREE( pv, pxLink->xBlockSize );
+					prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) );
+					xNumberOfSuccessfulFrees++;
+				}
+				( void ) xTaskResumeAll();
+			}
+			else
+			{
+				mtCOVERAGE_TEST_MARKER();
+			}
+		}
+		else
+		{
+			mtCOVERAGE_TEST_MARKER();
+		}
+	}
+}
+/*-----------------------------------------------------------*/
+
+size_t xPortGetFreeHeapSize( void )
+{
+	return xFreeBytesRemaining;
+}
+/*-----------------------------------------------------------*/
+
+size_t xPortGetMinimumEverFreeHeapSize( void )
+{
+	return xMinimumEverFreeBytesRemaining;
+}
+/*-----------------------------------------------------------*/
+
+static void prvInsertBlockIntoFreeList( BlockLink_t *pxBlockToInsert )
+{
+BlockLink_t *pxIterator;
+uint8_t *puc;
+
+	/* Iterate through the list until a block is found that has a higher address
+	than the block being inserted. */
+	for( pxIterator = &xStart; pxIterator->pxNextFreeBlock < pxBlockToInsert; pxIterator = pxIterator->pxNextFreeBlock )
+	{
+		/* Nothing to do here, just iterate to the right position. */
+	}
+
+	/* Do the block being inserted, and the block it is being inserted after
+	make a contiguous block of memory? */
+	puc = ( uint8_t * ) pxIterator;
+	if( ( puc + pxIterator->xBlockSize ) == ( uint8_t * ) pxBlockToInsert )
+	{
+		pxIterator->xBlockSize += pxBlockToInsert->xBlockSize;
+		pxBlockToInsert = pxIterator;
+	}
+	else
+	{
+		mtCOVERAGE_TEST_MARKER();
+	}
+
+	/* Do the block being inserted, and the block it is being inserted before
+	make a contiguous block of memory? */
+	puc = ( uint8_t * ) pxBlockToInsert;
+	if( ( puc + pxBlockToInsert->xBlockSize ) == ( uint8_t * ) pxIterator->pxNextFreeBlock )
+	{
+		if( pxIterator->pxNextFreeBlock != pxEnd )
+		{
+			/* Form one big block from the two blocks. */
+			pxBlockToInsert->xBlockSize += pxIterator->pxNextFreeBlock->xBlockSize;
+			pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock->pxNextFreeBlock;
+		}
+		else
+		{
+			pxBlockToInsert->pxNextFreeBlock = pxEnd;
+		}
+	}
+	else
+	{
+		pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock;
+	}
+
+	/* If the block being inserted plugged a gab, so was merged with the block
+	before and the block after, then it's pxNextFreeBlock pointer will have
+	already been set, and should not be set here as that would make it point
+	to itself. */
+	if( pxIterator != pxBlockToInsert )
+	{
+		pxIterator->pxNextFreeBlock = pxBlockToInsert;
+	}
+	else
+	{
+		mtCOVERAGE_TEST_MARKER();
+	}
+}
+/*-----------------------------------------------------------*/
+
+void vPortDefineHeapRegions( const HeapRegion_t * const pxHeapRegions )
+{
+BlockLink_t *pxFirstFreeBlockInRegion = NULL, *pxPreviousFreeBlock;
+size_t xAlignedHeap;
+size_t xTotalRegionSize, xTotalHeapSize = 0;
+BaseType_t xDefinedRegions = 0;
+size_t xAddress;
+const HeapRegion_t *pxHeapRegion;
+
+	/* Can only call once! */
+	configASSERT( pxEnd == NULL );
+
+	pxHeapRegion = &( pxHeapRegions[ xDefinedRegions ] );
+
+	while( pxHeapRegion->xSizeInBytes > 0 )
+	{
+		xTotalRegionSize = pxHeapRegion->xSizeInBytes;
+
+		/* Ensure the heap region starts on a correctly aligned boundary. */
+		xAddress = ( size_t ) pxHeapRegion->pucStartAddress;
+		if( ( xAddress & portBYTE_ALIGNMENT_MASK ) != 0 )
+		{
+			xAddress += ( portBYTE_ALIGNMENT - 1 );
+			xAddress &= ~portBYTE_ALIGNMENT_MASK;
+
+			/* Adjust the size for the bytes lost to alignment. */
+			xTotalRegionSize -= xAddress - ( size_t ) pxHeapRegion->pucStartAddress;
+		}
+
+		xAlignedHeap = xAddress;
+
+		/* Set xStart if it has not already been set. */
+		if( xDefinedRegions == 0 )
+		{
+			/* xStart is used to hold a pointer to the first item in the list of
+			free blocks.  The void cast is used to prevent compiler warnings. */
+			xStart.pxNextFreeBlock = ( BlockLink_t * ) xAlignedHeap;
+			xStart.xBlockSize = ( size_t ) 0;
+		}
+		else
+		{
+			/* Should only get here if one region has already been added to the
+			heap. */
+			configASSERT( pxEnd != NULL );
+
+			/* Check blocks are passed in with increasing start addresses. */
+			configASSERT( xAddress > ( size_t ) pxEnd );
+		}
+
+		/* Remember the location of the end marker in the previous region, if
+		any. */
+		pxPreviousFreeBlock = pxEnd;
+
+		/* pxEnd is used to mark the end of the list of free blocks and is
+		inserted at the end of the region space. */
+		xAddress = xAlignedHeap + xTotalRegionSize;
+		xAddress -= xHeapStructSize;
+		xAddress &= ~portBYTE_ALIGNMENT_MASK;
+		pxEnd = ( BlockLink_t * ) xAddress;
+		pxEnd->xBlockSize = 0;
+		pxEnd->pxNextFreeBlock = NULL;
+
+		/* To start with there is a single free block in this region that is
+		sized to take up the entire heap region minus the space taken by the
+		free block structure. */
+		pxFirstFreeBlockInRegion = ( BlockLink_t * ) xAlignedHeap;
+		pxFirstFreeBlockInRegion->xBlockSize = xAddress - ( size_t ) pxFirstFreeBlockInRegion;
+		pxFirstFreeBlockInRegion->pxNextFreeBlock = pxEnd;
+
+		/* If this is not the first region that makes up the entire heap space
+		then link the previous region to this region. */
+		if( pxPreviousFreeBlock != NULL )
+		{
+			pxPreviousFreeBlock->pxNextFreeBlock = pxFirstFreeBlockInRegion;
+		}
+
+		xTotalHeapSize += pxFirstFreeBlockInRegion->xBlockSize;
+
+		/* Move onto the next HeapRegion_t structure. */
+		xDefinedRegions++;
+		pxHeapRegion = &( pxHeapRegions[ xDefinedRegions ] );
+	}
+
+	xMinimumEverFreeBytesRemaining = xTotalHeapSize;
+	xFreeBytesRemaining = xTotalHeapSize;
+
+	/* Check something was actually defined before it is accessed. */
+	configASSERT( xTotalHeapSize );
+
+	/* Work out the position of the top bit in a size_t variable. */
+	xBlockAllocatedBit = ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 );
+}
+/*-----------------------------------------------------------*/
+
+void vPortGetHeapStats( HeapStats_t *pxHeapStats )
+{
+BlockLink_t *pxBlock;
+size_t xBlocks = 0, xMaxSize = 0, xMinSize = portMAX_DELAY; /* portMAX_DELAY used as a portable way of getting the maximum value. */
+
+	vTaskSuspendAll();
+	{
+		pxBlock = xStart.pxNextFreeBlock;
+
+		/* pxBlock will be NULL if the heap has not been initialised.  The heap
+		is initialised automatically when the first allocation is made. */
+		if( pxBlock != NULL )
+		{
+			do
+			{
+				/* Increment the number of blocks and record the largest block seen
+				so far. */
+				xBlocks++;
+
+				if( pxBlock->xBlockSize > xMaxSize )
+				{
+					xMaxSize = pxBlock->xBlockSize;
+				}
+
+				/* Heap five will have a zero sized block at the end of each
+				each region - the block is only used to link to the next
+				heap region so it not a real block. */
+				if( pxBlock->xBlockSize != 0 )
+				{
+					if( pxBlock->xBlockSize < xMinSize )
+					{
+						xMinSize = pxBlock->xBlockSize;
+					}
+				}
+
+				/* Move to the next block in the chain until the last block is
+				reached. */
+				pxBlock = pxBlock->pxNextFreeBlock;
+			} while( pxBlock != pxEnd );
+		}
+	}
+	xTaskResumeAll();
+
+	pxHeapStats->xSizeOfLargestFreeBlockInBytes = xMaxSize;
+	pxHeapStats->xSizeOfSmallestFreeBlockInBytes = xMinSize;
+	pxHeapStats->xNumberOfFreeBlocks = xBlocks;
+
+	taskENTER_CRITICAL();
+	{
+		pxHeapStats->xAvailableHeapSpaceInBytes = xFreeBytesRemaining;
+		pxHeapStats->xNumberOfSuccessfulAllocations = xNumberOfSuccessfulAllocations;
+		pxHeapStats->xNumberOfSuccessfulFrees = xNumberOfSuccessfulFrees;
+		pxHeapStats->xMinimumEverFreeBytesRemaining = xMinimumEverFreeBytesRemaining;
+	}
+	taskEXIT_CRITICAL();
+}
+
@@ -0,0 +1,530 @@
+/*
+ * FreeRTOS Kernel V10.3.1
+ * 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.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+/*-----------------------------------------------------------
+ * Implementation of functions defined in portable.h for the ARM CM0 port.
+ *----------------------------------------------------------*/
+
+/* Scheduler includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+/* Constants required to manipulate the NVIC. */
+#define portNVIC_SYSTICK_CTRL_REG			( * ( ( volatile uint32_t * ) 0xe000e010 ) )
+#define portNVIC_SYSTICK_LOAD_REG			( * ( ( volatile uint32_t * ) 0xe000e014 ) )
+#define portNVIC_SYSTICK_CURRENT_VALUE_REG	( * ( ( volatile uint32_t * ) 0xe000e018 ) )
+#define portNVIC_INT_CTRL_REG				( * ( ( volatile uint32_t * ) 0xe000ed04 ) )
+#define portNVIC_SYSPRI2_REG				( * ( ( volatile uint32_t * ) 0xe000ed20 ) )
+#define portNVIC_SYSTICK_CLK_BIT			( 1UL << 2UL )
+#define portNVIC_SYSTICK_INT_BIT			( 1UL << 1UL )
+#define portNVIC_SYSTICK_ENABLE_BIT			( 1UL << 0UL )
+#define portNVIC_SYSTICK_COUNT_FLAG_BIT		( 1UL << 16UL )
+#define portNVIC_PENDSVSET_BIT				( 1UL << 28UL )
+#define portMIN_INTERRUPT_PRIORITY			( 255UL )
+#define portNVIC_PENDSV_PRI					( portMIN_INTERRUPT_PRIORITY << 16UL )
+#define portNVIC_SYSTICK_PRI				( portMIN_INTERRUPT_PRIORITY << 24UL )
+
+/* Constants required to set up the initial stack. */
+#define portINITIAL_XPSR			( 0x01000000 )
+
+/* The systick is a 24-bit counter. */
+#define portMAX_24_BIT_NUMBER		( 0xffffffUL )
+
+/* A fiddle factor to estimate the number of SysTick counts that would have
+ occurred while the SysTick counter is stopped during tickless idle
+ calculations. */
+#ifndef portMISSED_COUNTS_FACTOR
+	#define portMISSED_COUNTS_FACTOR	( 45UL )
+#endif
+
+/* Constants used with memory barrier intrinsics. */
+#define portSY_FULL_READ_WRITE		( 15 )
+
+/* Legacy macro for backward compatibility only.  This macro used to be used to
+replace the function that configures the clock used to generate the tick
+interrupt (prvSetupTimerInterrupt()), but now the function is declared weak so
+the application writer can override it by simply defining a function of the
+same name (vApplicationSetupTickInterrupt()). */
+#ifndef configOVERRIDE_DEFAULT_TICK_CONFIGURATION
+	#define configOVERRIDE_DEFAULT_TICK_CONFIGURATION 0
+#endif
+
+/* Each task maintains its own interrupt status in the critical nesting
+variable. */
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;
+
+/* The number of SysTick increments that make up one tick period. */
+#if( configUSE_TICKLESS_IDLE == 1 )
+	static uint32_t ulTimerCountsForOneTick = 0;
+#endif /* configUSE_TICKLESS_IDLE */
+
+/* The maximum number of tick periods that can be suppressed is limited by the
+ 24 bit resolution of the SysTick timer. */
+#if( configUSE_TICKLESS_IDLE == 1 )
+	static uint32_t xMaximumPossibleSuppressedTicks = 0;
+#endif /* configUSE_TICKLESS_IDLE */
+
+ /* Compensate for the CPU cycles that pass while the SysTick is stopped (low
+ power functionality only.
+*/
+#if( configUSE_TICKLESS_IDLE == 1 )
+	static uint32_t ulStoppedTimerCompensation = 0;
+#endif /* configUSE_TICKLESS_IDLE */
+
+/*
+ * Setup the timer to generate the tick interrupts.  The implementation in this
+ * file is weak to allow application writers to change the timer used to
+ * generate the tick interrupt.
+ */
+void vPortSetupTimerInterrupt( void );
+
+/*
+ * Exception handlers.
+ */
+void xPortPendSVHandler( void );
+void xPortSysTickHandler( void );
+void vPortSVCHandler( void );
+
+/*
+ * Start first task is a separate function so it can be tested in isolation.
+ */
+static void prvPortStartFirstTask( void );
+
+/*
+ * Used to catch tasks that attempt to return from their implementing function.
+ */
+static void prvTaskExitError( void );
+
+/*-----------------------------------------------------------*/
+
+/*
+ * See header file for description.
+ */
+StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
+{
+	/* Simulate the stack frame as it would be created by a context switch
+	interrupt. */
+	pxTopOfStack--; /* Offset added to account for the way the MCU uses the stack on entry/exit of interrupts. */
+	*pxTopOfStack = portINITIAL_XPSR;	/* xPSR */
+	pxTopOfStack--;
+	*pxTopOfStack = ( StackType_t ) pxCode;	/* PC */
+	pxTopOfStack--;
+	*pxTopOfStack = ( StackType_t ) prvTaskExitError;	/* LR */
+	pxTopOfStack -= 5;	/* R12, R3, R2 and R1. */
+	*pxTopOfStack = ( StackType_t ) pvParameters;	/* R0 */
+	pxTopOfStack -= 8; /* R11..R4. */
+
+	return pxTopOfStack;
+}
+/*-----------------------------------------------------------*/
+
+static void prvTaskExitError( void )
+{
+	/* A function that implements a task must not exit or attempt to return to
+	its caller as there is nothing to return to.  If a task wants to exit it
+	should instead call vTaskDelete( NULL ).
+
+	Artificially force an assert() to be triggered if configASSERT() is
+	defined, then stop here so application writers can catch the error. */
+	configASSERT( uxCriticalNesting == ~0UL );
+	portDISABLE_INTERRUPTS();
+	for( ;; );
+}
+/*-----------------------------------------------------------*/
+
+void vPortSVCHandler( void )
+{
+	/* This function is no longer used, but retained for backward
+	compatibility. */
+}
+/*-----------------------------------------------------------*/
+
+__asm void prvPortStartFirstTask( void )
+{
+	extern pxCurrentTCB;
+
+	PRESERVE8
+
+	/* The MSP stack is not reset as, unlike on M3/4 parts, there is no vector
+	table offset register that can be used to locate the initial stack value.
+	Not all M0 parts have the application vector table at address 0. */
+
+	ldr	r3, =pxCurrentTCB	/* Obtain location of pxCurrentTCB. */
+	ldr r1, [r3]
+	ldr r0, [r1]			/* The first item in pxCurrentTCB is the task top of stack. */
+	adds r0, #32			/* Discard everything up to r0. */
+	msr psp, r0				/* This is now the new top of stack to use in the task. */
+	movs r0, #2				/* Switch to the psp stack. */
+	msr CONTROL, r0
+	isb
+	pop {r0-r5}				/* Pop the registers that are saved automatically. */
+	mov lr, r5				/* lr is now in r5. */
+	pop {r3}				/* The return address is now in r3. */
+	pop {r2}				/* Pop and discard the XPSR. */
+	cpsie i					/* The first task has its context and interrupts can be enabled. */
+	bx r3					/* Finally, jump to the user defined task code. */
+
+	ALIGN
+}
+/*-----------------------------------------------------------*/
+
+/*
+ * See header file for description.
+ */
+BaseType_t xPortStartScheduler( void )
+{
+	/* Make PendSV, CallSV and SysTick the same priority as the kernel. */
+	portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;
+	portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;
+
+	/* Start the timer that generates the tick ISR.  Interrupts are disabled
+	here already. */
+	vPortSetupTimerInterrupt();
+
+	/* Initialise the critical nesting count ready for the first task. */
+	uxCriticalNesting = 0;
+
+	/* Start the first task. */
+	prvPortStartFirstTask();
+
+	/* Should not get here! */
+	return 0;
+}
+/*-----------------------------------------------------------*/
+
+void vPortEndScheduler( void )
+{
+	/* Not implemented in ports where there is nothing to return to.
+	Artificially force an assert. */
+	configASSERT( uxCriticalNesting == 1000UL );
+}
+/*-----------------------------------------------------------*/
+
+void vPortYield( void )
+{
+	/* Set a PendSV to request a context switch. */
+	portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
+
+	/* Barriers are normally not required but do ensure the code is completely
+	within the specified behaviour for the architecture. */
+	__dsb( portSY_FULL_READ_WRITE );
+	__isb( portSY_FULL_READ_WRITE );
+}
+/*-----------------------------------------------------------*/
+
+void vPortEnterCritical( void )
+{
+    portDISABLE_INTERRUPTS();
+    uxCriticalNesting++;
+	__dsb( portSY_FULL_READ_WRITE );
+	__isb( portSY_FULL_READ_WRITE );
+}
+/*-----------------------------------------------------------*/
+
+void vPortExitCritical( void )
+{
+	configASSERT( uxCriticalNesting );
+	uxCriticalNesting--;
+	if( uxCriticalNesting == 0 )
+	{
+		portENABLE_INTERRUPTS();
+	}
+}
+/*-----------------------------------------------------------*/
+
+__asm uint32_t ulSetInterruptMaskFromISR( void )
+{
+	mrs r0, PRIMASK
+	cpsid i
+	bx lr
+}
+/*-----------------------------------------------------------*/
+
+__asm void vClearInterruptMaskFromISR( uint32_t ulMask )
+{
+	msr PRIMASK, r0
+	bx lr
+}
+/*-----------------------------------------------------------*/
+
+__asm void xPortPendSVHandler( void )
+{
+	extern vTaskSwitchContext
+	extern pxCurrentTCB
+
+	PRESERVE8
+
+	mrs r0, psp
+
+	ldr	r3, =pxCurrentTCB 	/* Get the location of the current TCB. */
+	ldr	r2, [r3]
+
+	subs r0, #32			/* Make space for the remaining low registers. */
+	str r0, [r2]			/* Save the new top of stack. */
+	stmia r0!, {r4-r7}		/* Store the low registers that are not saved automatically. */
+	mov r4, r8				/* Store the high registers. */
+	mov r5, r9
+	mov r6, r10
+	mov r7, r11
+	stmia r0!, {r4-r7}
+
+	push {r3, r14}
+	cpsid i
+	bl vTaskSwitchContext
+	cpsie i
+	pop {r2, r3}			/* lr goes in r3. r2 now holds tcb pointer. */
+
+	ldr r1, [r2]
+	ldr r0, [r1]			/* The first item in pxCurrentTCB is the task top of stack. */
+	adds r0, #16			/* Move to the high registers. */
+	ldmia r0!, {r4-r7}		/* Pop the high registers. */
+	mov r8, r4
+	mov r9, r5
+	mov r10, r6
+	mov r11, r7
+
+	msr psp, r0				/* Remember the new top of stack for the task. */
+
+	subs r0, #32			/* Go back for the low registers that are not automatically restored. */
+	ldmia r0!, {r4-r7}      /* Pop low registers.  */
+
+	bx r3
+	ALIGN
+}
+/*-----------------------------------------------------------*/
+
+void xPortSysTickHandler( void )
+{
+uint32_t ulPreviousMask;
+
+	ulPreviousMask = portSET_INTERRUPT_MASK_FROM_ISR();
+	{
+		/* Increment the RTOS tick. */
+		if( xTaskIncrementTick() != pdFALSE )
+		{
+			/* Pend a context switch. */
+			portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
+		}
+	}
+	portCLEAR_INTERRUPT_MASK_FROM_ISR( ulPreviousMask );
+}
+/*-----------------------------------------------------------*/
+
+/*
+ * Setup the systick timer to generate the tick interrupts at the required
+ * frequency.
+ */
+#if( configOVERRIDE_DEFAULT_TICK_CONFIGURATION == 0 )
+
+	__weak void vPortSetupTimerInterrupt( void )
+	{
+		/* Calculate the constants required to configure the tick interrupt. */
+		#if( configUSE_TICKLESS_IDLE == 1 )
+			ulTimerCountsForOneTick = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ );
+			xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;
+			ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR;
+		#endif /* configUSE_TICKLESS_IDLE */
+
+		/* Stop and reset the SysTick. */
+		portNVIC_SYSTICK_CTRL_REG = 0UL;
+		portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;
+
+		/* Configure SysTick to interrupt at the requested rate. */
+		portNVIC_SYSTICK_LOAD_REG = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
+		portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
+	}
+
+#endif /* configOVERRIDE_DEFAULT_TICK_CONFIGURATION */
+/*-----------------------------------------------------------*/
+
+#if( configUSE_TICKLESS_IDLE == 1 )
+
+__weak void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )
+{
+uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements;
+TickType_t xModifiableIdleTime;
+
+	/* Make sure the SysTick reload value does not overflow the counter. */
+	if( xExpectedIdleTime > xMaximumPossibleSuppressedTicks )
+	{
+		xExpectedIdleTime = xMaximumPossibleSuppressedTicks;
+	}
+
+	/* Stop the SysTick momentarily. The time the SysTick is stopped for
+	is accounted for as best it can be, but using the tickless mode will
+	inevitably result in some tiny drift of the time maintained by the
+	kernel with respect to calendar time. */
+	portNVIC_SYSTICK_CTRL_REG &= ~portNVIC_SYSTICK_ENABLE_BIT;
+
+	/* Calculate the reload value required to wait xExpectedIdleTime
+	tick periods.  -1 is used because this code will execute part way
+	through one of the tick periods. */
+	ulReloadValue = portNVIC_SYSTICK_CURRENT_VALUE_REG + ( ulTimerCountsForOneTick * ( xExpectedIdleTime - 1UL ) );
+	if( ulReloadValue > ulStoppedTimerCompensation )
+	{
+		ulReloadValue -= ulStoppedTimerCompensation;
+	}
+
+	/* Enter a critical section but don't use the taskENTER_CRITICAL()
+	method as that will mask interrupts that should exit sleep mode. */
+	__disable_irq();
+	__dsb( portSY_FULL_READ_WRITE );
+	__isb( portSY_FULL_READ_WRITE );
+
+	/* If a context switch is pending or a task is waiting for the scheduler
+	to be unsuspended then abandon the low power entry. */
+	if( eTaskConfirmSleepModeStatus() == eAbortSleep )
+	{
+		/* Restart from whatever is left in the count register to complete
+		this tick period. */
+		portNVIC_SYSTICK_LOAD_REG = portNVIC_SYSTICK_CURRENT_VALUE_REG;
+
+		/* Restart SysTick. */
+		portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;
+
+		/* Reset the reload register to the value required for normal tick
+		periods. */
+		portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
+
+		/* Re-enable interrupts - see comments above __disable_irq() call
+		above. */
+		__enable_irq();
+	}
+	else
+	{
+		/* Set the new reload value. */
+		portNVIC_SYSTICK_LOAD_REG = ulReloadValue;
+
+		/* Clear the SysTick count flag and set the count value back to
+		zero. */
+		portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;
+
+		/* Restart SysTick. */
+		portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;
+
+		/* Sleep until something happens. configPRE_SLEEP_PROCESSING() can
+		set its parameter to 0 to indicate that its implementation contains
+		its own wait for interrupt or wait for event instruction, and so wfi
+		should not be executed again. However, the original expected idle
+		time variable must remain unmodified, so a copy is taken. */
+		xModifiableIdleTime = xExpectedIdleTime;
+		configPRE_SLEEP_PROCESSING( xModifiableIdleTime );
+		if( xModifiableIdleTime > 0 )
+		{
+			__dsb( portSY_FULL_READ_WRITE );
+			__wfi();
+			__isb( portSY_FULL_READ_WRITE );
+		}
+		configPOST_SLEEP_PROCESSING( xExpectedIdleTime );
+
+		/* Re-enable interrupts to allow the interrupt that brought the MCU
+		out of sleep mode to execute immediately. see comments above
+		__disable_interrupt() call above. */
+		__enable_irq();
+		__dsb( portSY_FULL_READ_WRITE );
+		__isb( portSY_FULL_READ_WRITE );
+
+		/* Disable interrupts again because the clock is about to be stopped
+		and interrupts that execute while the clock is stopped will increase
+		any slippage between the time maintained by the RTOS and calendar
+		time. */
+		__disable_irq();
+		__dsb( portSY_FULL_READ_WRITE );
+		__isb( portSY_FULL_READ_WRITE );
+
+		/* Disable the SysTick clock without reading the
+		portNVIC_SYSTICK_CTRL_REG register to ensure the
+		portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set.  Again,
+		the time the SysTick is stopped for is accounted for as best it can
+		be, but using the tickless mode will inevitably result in some tiny
+		drift of the time maintained by the kernel with respect to calendar
+		time*/
+		portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT );
+
+		/* Determine if the SysTick clock has already counted to zero and
+		been set back to the current reload value (the reload back being
+		correct for the entire expected idle time) or if the SysTick is yet
+		to count to zero (in which case an interrupt other than the SysTick
+		must have brought the system out of sleep mode). */
+		if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )
+		{
+			uint32_t ulCalculatedLoadValue;
+
+			/* The tick interrupt is already pending, and the SysTick count
+			reloaded with ulReloadValue.  Reset the
+			portNVIC_SYSTICK_LOAD with whatever remains of this tick
+			period. */
+			ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
+
+			/* Don't allow a tiny value, or values that have somehow
+			underflowed because the post sleep hook did something
+			that took too long. */
+			if( ( ulCalculatedLoadValue < ulStoppedTimerCompensation ) || ( ulCalculatedLoadValue > ulTimerCountsForOneTick ) )
+			{
+				ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL );
+			}
+
+			portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;
+
+			/* As the pending tick will be processed as soon as this
+			function exits, the tick value maintained by the tick is stepped
+			forward by one less than the time spent waiting. */
+			ulCompleteTickPeriods = xExpectedIdleTime - 1UL;
+		}
+		else
+		{
+			/* Something other than the tick interrupt ended the sleep.
+			Work out how long the sleep lasted rounded to complete tick
+			periods (not the ulReload value which accounted for part
+			ticks). */
+			ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - portNVIC_SYSTICK_CURRENT_VALUE_REG;
+
+			/* How many complete tick periods passed while the processor
+			was waiting? */
+			ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;
+
+			/* The reload value is set to whatever fraction of a single tick
+			period remains. */
+			portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1UL ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;
+		}
+
+		/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD
+		again, then set portNVIC_SYSTICK_LOAD back to its standard
+		value. */
+		portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;
+		portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;
+		vTaskStepTick( ulCompleteTickPeriods );
+		portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
+
+		/* Exit with interrpts enabled. */
+		__enable_irq();
+	}
+}
+
+#endif /* #if configUSE_TICKLESS_IDLE */
+
+/*-----------------------------------------------------------*/
@@ -0,0 +1,121 @@
+/*
+ * FreeRTOS Kernel V10.3.1
+ * 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.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+
+#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. */
+#define portCHAR		char
+#define portFLOAT		float
+#define portDOUBLE		double
+#define portLONG		long
+#define portSHORT		short
+#define portSTACK_TYPE	uint32_t
+#define portBASE_TYPE	long
+
+typedef portSTACK_TYPE StackType_t;
+typedef long BaseType_t;
+typedef unsigned long 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
+
+	/* 32-bit tick type on a 32-bit architecture, so reads of the tick count do
+	not need to be guarded with a critical section. */
+	#define portTICK_TYPE_IS_ATOMIC 1
+#endif
+/*-----------------------------------------------------------*/
+
+/* Architecture specifics. */
+#define portSTACK_GROWTH			( -1 )
+#define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
+#define portBYTE_ALIGNMENT			8
+/*-----------------------------------------------------------*/
+
+
+/* Scheduler utilities. */
+extern void vPortYield( void );
+#define portNVIC_INT_CTRL_REG		( * ( ( volatile uint32_t * ) 0xe000ed04 ) )
+#define portNVIC_PENDSVSET_BIT		( 1UL << 28UL )
+#define portYIELD()					vPortYield()
+#define portEND_SWITCHING_ISR( xSwitchRequired ) if( xSwitchRequired ) portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT
+#define portYIELD_FROM_ISR( x ) portEND_SWITCHING_ISR( x )
+/*-----------------------------------------------------------*/
+
+/* Critical section management. */
+extern void vPortEnterCritical( void );
+extern void vPortExitCritical( void );
+extern uint32_t ulSetInterruptMaskFromISR( void );
+extern void vClearInterruptMaskFromISR( uint32_t ulMask );
+
+#define portSET_INTERRUPT_MASK_FROM_ISR()		ulSetInterruptMaskFromISR()
+#define portCLEAR_INTERRUPT_MASK_FROM_ISR(x)	vClearInterruptMaskFromISR( x )
+#define portDISABLE_INTERRUPTS()				__disable_irq()
+#define portENABLE_INTERRUPTS()					__enable_irq()
+#define portENTER_CRITICAL()					vPortEnterCritical()
+#define portEXIT_CRITICAL()						vPortExitCritical()
+
+/*-----------------------------------------------------------*/
+
+/* Tickless idle/low power functionality. */
+#ifndef portSUPPRESS_TICKS_AND_SLEEP
+	extern void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime );
+	#define portSUPPRESS_TICKS_AND_SLEEP( xExpectedIdleTime ) vPortSuppressTicksAndSleep( xExpectedIdleTime )
+#endif
+/*-----------------------------------------------------------*/
+
+/* Task function macros as described on the FreeRTOS.org WEB site. */
+#define portTASK_FUNCTION_PROTO( vFunction, pvParameters ) void vFunction( void *pvParameters )
+#define portTASK_FUNCTION( vFunction, pvParameters ) void vFunction( void *pvParameters )
+
+#define portNOP()
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PORTMACRO_H */
+