Memory must be allocated for the host driver's control block. A dynamic memory model can be used if SL_MEMORY_MGMT_DYNAMIC is defined in user.h. malloc and free are defined according to the FreeRTOS memory model.

user.h:

#include <stdlib.h>

#define sl_Malloc(Size)    pvPortMalloc(Size)
#define sl_Free(pMem)      vPortFree(pMem)