[rpi bsp] configure fb section in mmu table and improvement for mailbox

[Chris Johns]

On 29/07/2015 8:04 pm, Sebastian Huber wrote:
> 
> A custom workspace initialization can be done via
> bsp_work_area_initialize().
> 

On the zynq the ethernet driver from Ric (SLAC) for the in tree
(existing) IP stack there is:

 uint8_t*  start;
 size_t    size = 0x100000;
 uintptr_t boundary  = (uintptr_t) 0;
 uintptr_t alignment = (uintptr_t) 0x100000;
 start = (uint8_t*) rtems_heap_allocate_aligned_with_boundary(size,
                                                              alignment,
                                                              boundary);
 arm_cp15_set_translation_table_entries(start,
                                        @start[size],
                                        ARMV7_MMU_DEVICE);

This creates an MMU entry at runtime for a 1M aligned block of memory
that has the cache disabled.

Chris