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.

c/src/lib/libbsp/shared/bootcard.c

@@ -8,25 +8,8 @@
  *  This is the C entry point for ALL RTEMS BSPs.  It is invoked
  *  from the assembly language initialization file usually called
  *  start.S.  It provides the framework for the BSP initialization
- *  sequence.  The basic flow of initialization is:
- *
- *  + start.S: basic CPU setup (stack, zero BSS)
- *    + boot_card
- *      + bspstart.c: bsp_start - more advanced initialization
- *      + obtain information on BSP memory and allocate RTEMS Workspace
- *      + rtems_initialize_data_structures
- *      + allocate memory to C Program Heap
- *      + initialize C Library and C Program Heap
- *      + rtems_initialize_before_drivers
- *      + bsp_predriver_hook
- *      + rtems_initialize_device_drivers
- *        - all device drivers
- *      + bsp_postdriver_hook
- *      + rtems_initialize_start_multitasking
- *        - 1st task executes C++ global constructors
- *          .... appplication runs ...
- *          - exit
- *      + will not return to here
+ *  sequence.  For the basic flow of initialization see RTEMS C User's Guide,
+ *  Initialization Manager.
  *
  *  This style of initialization ensures that the C++ global
  *  constructors are executed after RTEMS is initialized.
@@ -46,6 +29,7 @@
 #include <bsp/bootcard.h>
 
 #include <rtems.h>
+#include <rtems/sysinit.h>
 
 /*
  *  At most a single pointer to the cmdline for those target
@@ -53,6 +37,36 @@
  */
 const char *bsp_boot_cmdline;
 
+RTEMS_SYSINIT_ITEM(
+  bsp_work_area_initialize,
+  RTEMS_SYSINIT_BSP_WORK_AREAS,
+  RTEMS_SYSINIT_ORDER_MIDDLE
+);
+
+RTEMS_SYSINIT_ITEM(
+  bsp_start,
+  RTEMS_SYSINIT_BSP_START,
+  RTEMS_SYSINIT_ORDER_MIDDLE
+);
+
+RTEMS_SYSINIT_ITEM(
+  bsp_libc_init,
+  RTEMS_SYSINIT_BSP_LIBC,
+  RTEMS_SYSINIT_ORDER_MIDDLE
+);
+
+RTEMS_SYSINIT_ITEM(
+  bsp_predriver_hook,
+  RTEMS_SYSINIT_BSP_PRE_DRIVERS,
+  RTEMS_SYSINIT_ORDER_MIDDLE
+);
+
+RTEMS_SYSINIT_ITEM(
+  bsp_postdriver_hook,
+  RTEMS_SYSINIT_BSP_POST_DRIVERS,
+  RTEMS_SYSINIT_ORDER_MIDDLE
+);
+
 /*
  *  This is the initialization framework routine that weaves together
  *  calls to RTEMS and the BSP in the proper sequence to initialize
@@ -73,59 +87,7 @@ void boot_card(
 
   bsp_boot_cmdline = cmdline;
 
-  /*
-   *  Initialize the RTEMS Workspace and the C Program Heap.
-   */
-  bsp_work_area_initialize();
-
-  /*
-   * Invoke Board Support Package initialization routine written in C.
-   */
-  bsp_start();
-
-  /*
-   *  Initialize RTEMS data structures
-   */
-  rtems_initialize_data_structures();
-
-  /*
-   *  Initialize the C library for those BSPs using the shared
-   *  framework.
-   */
-  bsp_libc_init();
-
-  /*
-   *  Let RTEMS perform initialization it requires before drivers
-   *  are allowed to be initialized.
-   */
-  rtems_initialize_before_drivers();
-
-  /*
-   *  Execute BSP specific pre-driver hook. Drivers haven't gotten
-   *  to initialize yet so this is a good chance to initialize
-   *  buses, spurious interrupt handlers, etc..
-   *
-   *  NOTE: Many BSPs do not require this handler and use the
-   *        shared stub.
-   */
-  bsp_predriver_hook();
-
-  /*
-   *  Initialize all device drivers.
-   */
-  rtems_initialize_device_drivers();
-
-  /*
-   *  Invoke the postdriver hook.  This normally opens /dev/console
-   *  for use as stdin, stdout, and stderr.
-   */
-  bsp_postdriver_hook();
-
-  /*
-   *  Complete initialization of RTEMS and switch to the first task.
-   *  Global C++ constructors will be executed in the context of that task.
-   */
-  rtems_initialize_start_multitasking();
+  rtems_initialize_executive();
 
   /***************************************************************
    ***************************************************************

c/src/lib/libbsp/shared/include/bootcard.h

@@ -71,26 +71,8 @@ void bsp_reset(void);
  * assembly language initialization file usually called @c start.S which does
  * the basic CPU setup (stack, C runtime environment, zero BSS, load other
  * sections) and calls afterwards boot_card().  The boot card function provides
- * the framework for the BSP initialization sequence.  The basic flow of
- * initialization is:
- *
- * - disable interrupts, interrupts will be enabled during the first context
- *   switch
- * - bsp_work_area_initialize() - initialize the RTEMS Workspace and the C
- *   Program Heap
- * - bsp_start() - more advanced initialization
- * - rtems_initialize_data_structures()
- * - initialize C Library
- * - rtems_initialize_before_drivers()
- * - bsp_predriver_hook()
- * - rtems_initialize_device_drivers()
- *   - initialization of all device drivers
- * - bsp_postdriver_hook()
- * - rtems_initialize_start_multitasking()
- *   - 1st task executes C++ global constructors
- *   - .... application runs ...
- *   - exit
- * - will not return to here
+ * the framework for the BSP initialization sequence.  For the basic flow of
+ * initialization see RTEMS C User's Guide, Initialization Manager.
  *
  * This style of initialization ensures that the C++ global constructors are
  * executed after RTEMS is initialized.