#define vPortSVCHandler SVC_Handler
#define xPortPendSVHandler PendSV_Handler
#define xPortSysTickHandler SysTick_Handler

void (* const g_pfnVectors[])(void) =
  ...
  vPortSVCHandler,                         /*!< SVCall handler                    */
  ...
  xPortPendSVHandler,                      /*!< The PendSV handler                */
  xPortSysTickHandler,                     /*!< The SysTick handler               */

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;
        }
...

#define pdFALSE            ( ( BaseType_t ) 0 )