Some hardware requires 8 byte alignment of variables (MAC modules of Atmel I know about). With no cost this could be added to freeRTOS: just add these lines to heap_1 and heap_2:
#if portBYTE_ALIGNMENT == 8
#define heapBYTE_ALIGNMENT_MASK ( ( size_t ) 0x0007 )
Could this be done in the next version of the distro? (I try to reduce my work when OS is updated).