Changes between Version 7 and Version 8 of Developer/Projects/SequencedInitialization

Timestamp:

05/11/10 12:56:19 (14 years ago)

Author:

Sh

Comment:

/* Implementation Alternatives */

Developer/Projects/SequencedInitialization

@@ -35 +35 @@
 
 Code and data size measurements should be made before and after the implementation is done on the sparc/sis and arm/rtl22xx_t BSPs.  These BSPs are used for code size analysis across releases.
-= Implementation Alternatives =
+= Implementation Details =
 
 = Definitions =
@@ -74 +74 @@
  *  [CON] Depends on GNU linker feature.
  *  [CON] Order information must be derived from the place in the linker set.  It is impossible to derive the order value specified at compile time.
+
+Linker command file example:
+ .rtems : {
+         . = ALIGN(8);
+         rtems_sysinit_begin = .;
+         *(SORT(.rtems.sysinit.*))
+         rtems_sysinit_end = .;
+ }
+
+Header file example:
+ #define RTEMS_SYSINIT_MAKE_STRING(str) #str
+ 
+ #define RTEMS_SYSINIT(group, func) \
+         static const uintptr_t \
+         rtems_sysinit_ ## func \
+         __attribute__((section(".rtems.sysinit." RTEMS_SYSINIT_MAKE_STRING(group)))) \
+         __attribute__((used)) \
+         = (uintptr_t) &func
+ 
+ extern uintptr_t rtems_sysinit_begin [];
+ 
+ extern uintptr_t rtems_sysinit_end [];
+= Initialization and Termination =
+
+
+The sequenced initialization can be used also for termination. We have two alternatives here:
+
+# Add a second linker set for termination items.
+# Use the initialization linker set and pass a state parameter to the initialization function.  The initialization functions should be called in reversed initialization order for termination.
+
+We should use the second approach.  This is more flexible and reduces the code inside the linker command files.  Linker command files are hard to maintain.
+
+Proposed API:
+ typedef enum {
+        RTEMS_SYSINIT_STARTUP,
+        RTEMS_SYSINIT_TERMINATE
+ } rtems_sysinit_state;
+ 
+ typedef void (*rtems_sysinit_function)(rtems_sysinit_state state);
 = Open Projects =