The work area initialization was done by the BSP through
bsp_work_area_initialize(). This approach predated the system
initialization through the system initialization linker set. The
workspace and C program heap were unconditionally initialized. The aim
is to support RTEMS application configurations which do not need the
workspace and C program heap. In these configurations, the workspace
and C prgram heap should not get initialized.
Change all bsp_work_area_initialize() to implement _Memory_Get()
instead. Move the dirty memory, sbrk(), per-CPU data, workspace, and
malloc() heap initialization into separate system initialization steps.
This makes it also easier to test the individual initialization steps.
This change adds a dependency to _Heap_Extend() to all BSPs. This
dependency will be removed in a follow up change.
Update #3838.
The BSP tried to get the size of the SDRAM based on the revision code.
Unfortunately the code had some bugs so that the default size has been
used. Beneath that the MMU table hasn't been adapted.
This patch queries the SDRAM size via a special VC Mailbox call instead.
For the MMU adaption a simmilar method to the one in the imx BSP is
used.
