@ -84,14 +84,11 @@ task.h is included from an application file. */
# undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
/* Block sizes must not get too small. */
# define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( heapSTRUCT_SIZE * 2 ) )
# define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( xHeapStructSize * 2 ) )
/* Assumes 8bit bytes! */
# define heapBITS_PER_BYTE ( ( size_t ) 8 )
/* A few bytes might be lost to byte aligning the heap start address. */
# define heapADJUSTED_HEAP_SIZE ( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT )
/* Allocate the memory for the heap. */
static uint8_t ucHeap [ configTOTAL_HEAP_SIZE ] ;
@ -123,18 +120,15 @@ 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 uint16_t heapSTRUCT_SIZE = ( ( sizeof ( BlockLink_t ) + ( portBYTE_ALIGNMENT - 1 ) ) & ~ portBYTE_ALIGNMENT_MASK ) ;
/* Ensure the pxEnd pointer will end up on the correct byte alignment. */
static const size_t xTotalHeapSize = ( ( size_t ) heapADJUSTED_HEAP_SIZE ) & ( ( size_t ) ~ portBYTE_ALIGNMENT_MASK ) ;
static const size_t xHeapStructSize = ( ( sizeof ( BlockLink_t ) + ( portBYTE_ALIGNMENT - 1 ) ) & ~ 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 free bytes remaining, but says nothing about
fragmentation . */
static size_t xFreeBytesRemaining = ( ( size_t ) heapADJUSTED_HEAP_SIZE ) & ( ( size_t ) ~ portBYTE_ALIGNMENT_MASK ) ;
static size_t xMinimumEverFreeBytesRemaining = ( ( size_t ) heapADJUSTED_HEAP_SIZE ) & ( ( size_t ) ~ portBYTE_ALIGNMENT_MASK ) ;
static size_t xFreeBytesRemaining = 0U ;
static size_t xMinimumEverFreeBytesRemaining = 0U ;
/* 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
@ -172,7 +166,7 @@ void *pvReturn = NULL;
structure in addition to the requested amount of bytes . */
if ( xWantedSize > 0 )
{
xWantedSize + = heapSTRUCT_SIZE ;
xWantedSize + = xHeapStructSize ;
/* Ensure that blocks are always aligned to the required number
of bytes . */
@ -180,6 +174,7 @@ void *pvReturn = NULL;
{
/* Byte alignment required. */
xWantedSize + = ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) ;
configASSERT ( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) = = 0 ) ;
}
else
{
@ -209,7 +204,7 @@ void *pvReturn = NULL;
{
/* Return the memory space pointed to - jumping over the
BlockLink_t structure at its start . */
pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock - > pxNextFreeBlock ) + heapSTRUCT_SIZE ) ;
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 . */
@ -224,6 +219,7 @@ void *pvReturn = NULL;
cast is used to prevent byte alignment warnings from the
compiler . */
pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize ) ;
configASSERT ( ( ( ( uint32_t ) pxNewBlockLink ) & portBYTE_ALIGNMENT_MASK ) = = 0 ) ;
/* Calculate the sizes of two blocks split from the
single block . */
@ -287,6 +283,7 @@ void *pvReturn = NULL;
}
# endif
configASSERT ( ( ( ( uint32_t ) pvReturn ) & portBYTE_ALIGNMENT_MASK ) = = 0 ) ;
return pvReturn ;
}
/*-----------------------------------------------------------*/
@ -300,7 +297,7 @@ BlockLink_t *pxLink;
{
/* The memory being freed will have an BlockLink_t structure immediately
before it . */
puc - = heapSTRUCT_SIZE ;
puc - = xHeapStructSize ;
/* This casting is to keep the compiler from issuing warnings. */
pxLink = ( void * ) puc ;
@ -360,10 +357,21 @@ void vPortInitialiseBlocks( void )
static void prvHeapInit ( void )
{
BlockLink_t * pxFirstFreeBlock ;
uint8_t * pucHeapEnd , * pucAlignedHeap ;
uint8_t * pucAlignedHeap ;
uint32_t ulAddress ;
size_t xTotalHeapSize = configTOTAL_HEAP_SIZE ;
/* Ensure the heap starts on a correctly aligned boundary. */
pucAlignedHeap = ( uint8_t * ) ( ( ( portPOINTER_SIZE_TYPE ) & ucHeap [ portBYTE_ALIGNMENT ] ) & ( ( portPOINTER_SIZE_TYPE ) ~ portBYTE_ALIGNMENT_MASK ) ) ;
ulAddress = ( uint32_t ) ucHeap ;
if ( ( ulAddress & portBYTE_ALIGNMENT_MASK ) ! = 0 )
{
ulAddress + = ( portBYTE_ALIGNMENT - 1 ) ;
ulAddress & = ~ portBYTE_ALIGNMENT_MASK ;
xTotalHeapSize - = ulAddress - ( uint32_t ) ucHeap ;
}
pucAlignedHeap = ( uint8_t * ) ulAddress ;
/* 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 . */
@ -372,21 +380,22 @@ uint8_t *pucHeapEnd, *pucAlignedHeap;
/* pxEnd is used to mark the end of the list of free blocks and is inserted
at the end of the heap space . */
pucHeapEnd = pucAlignedHeap + xTotalHeapSize ;
pucHeapEnd - = heapSTRUCT_SIZE ;
pxEnd = ( void * ) pucHeapEnd ;
configASSERT ( ( ( ( uint32_t ) pxEnd ) & ( ( uint32_t ) portBYTE_ALIGNMENT_MASK ) ) = = 0UL ) ;
ulAddress = ( ( uint32_t ) pucAlignedHeap ) + xTotalHeapSize ;
ulAddress - = xHeapStructSize ;
ulAddress & = ~ portBYTE_ALIGNMENT_MASK ;
pxEnd = ( void * ) ulAddress ;
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 = xTotalHeapSize - heapSTRUCT_SIZE ;
pxFirstFreeBlock - > xBlockSize = ulAddress - ( uint32_t ) pxFirstFreeBlock ;
pxFirstFreeBlock - > pxNextFreeBlock = pxEnd ;
/* The heap now contains pxEnd. */
xFreeBytesRemaining - = heapSTRUCT_SIZE ;
/* 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 ) ;