Use linker set for system initialization

Make rtems_initialize_data_structures(),
rtems_initialize_before_drivers() and rtems_initialize_device_drivers()
static.  Rename rtems_initialize_start_multitasking() to
rtems_initialize_executive() and call the registered system
initialization handlers in this function.  Add system initialization API
available via #include <rtems/sysinit.h>.  Update the documentation
accordingly.

This is no functional change, only the method to call the existing
initialization routines changes.  Instead of direct function calls a
table of function pointers contained in the new RTEMS system
initialization linker set is used.  This table looks like this (the
actual addresses depend on the target).

nm *.exe | grep _Linker | sort
0201a2d0 D _Linker_set__Sysinit_begin
0201a2d0 D _Linker_set__Sysinit_bsp_work_area_initialize
0201a2d4 D _Linker_set__Sysinit_bsp_start
0201a2d8 D _Linker_set__Sysinit_rtems_initialize_data_structures
0201a2dc D _Linker_set__Sysinit_bsp_libc_init
0201a2e0 D _Linker_set__Sysinit_rtems_initialize_before_drivers
0201a2e4 D _Linker_set__Sysinit_bsp_predriver_hook
0201a2e8 D _Linker_set__Sysinit_rtems_initialize_device_drivers
0201a2ec D _Linker_set__Sysinit_bsp_postdriver_hook
0201a2f0 D _Linker_set__Sysinit_end

Add test sptests/spsysinit01.

Update #2408.

0 files changed, 0 insertions, 0 deletions