+ Add configASSERT() into ARM Cortex-M ports to check the number of priority
bit settings.
+ Clear the 'control' register before starting ARM Cortex-M4F ports in case
the FPU is used before the scheduler is started. This just saves a few
bytes on the main stack as it prevents space being left for a later save
of FPU registers.
+ Added xSemaphoreGetMutexHolderFromISR().
+ Corrected use of portNVIC_PENDSVSET to portNVIC_PENDSVSET_BIT in MPU ports.
- Clear the SysTick current value register before starting the SysTick (only required if something uses SysTick before starting the scheduler).
- Ensure atomic operations are thread safe by executing clrex in the context switch.
Add RVDS ARM Cortex-M4F MPU port.
Increase the size of each buffer allocated to pbufs in the Microblaze lwIP demo to prevent pbufs chaining.
Use _start as the top of the stack for each Microblaze task, rather than NULL, as NULL was causing the Xilinx SDK to try and unwind the stack too far.
