1 files changed, 33 insertions, 26 deletions

diff --git a/cpukit/score/src/userext.c b/cpukit/score/src/userext.c
index 4b81daa4ea..78162f6cdd 100644
--- a/cpukit/score/src/userext.c
+++ b/cpukit/score/src/userext.c
@@ -16,44 +16,51 @@
  */
 
 #if HAVE_CONFIG_H
-#include "config.h"
+  #include "config.h"
 #endif
 
-#include <rtems/system.h>
 #include <rtems/config.h>
 #include <rtems/score/userext.h>
 #include <rtems/score/wkspace.h>
-#include <string.h>
 
-void _User_extensions_Handler_initialization(void)
+CHAIN_DEFINE_EMPTY( _User_extensions_Switches_list );
+
+typedef struct {
+  User_extensions_Switch_control *switch_control;
+} User_extensions_Switch_context;
+
+static void _User_extensions_Switch_visitor(
+  Thread_Control              *executing,
+  void                        *arg,
+  const User_extensions_Table *callouts
+)
 {
-  User_extensions_Control     *extension;
-  uint32_t                     i;
-  uint32_t                     number_of_extensions;
-  const User_extensions_Table *initial_extensions;
+  User_extensions_thread_switch_extension callout = callouts->thread_switch;
 
-  number_of_extensions = rtems_configuration_get_number_of_initial_extensions();
-  initial_extensions   = rtems_configuration_get_user_extension_table();
+  if ( callout != NULL ) {
+    User_extensions_Switch_context *ctx = arg;
+    User_extensions_Switch_control *ctrl = ctx->switch_control;
 
-  _Chain_Initialize_empty( &_User_extensions_List );
-  _Chain_Initialize_empty( &_User_extensions_Switches_list );
+    _Chain_Append_unprotected( &_User_extensions_Switches_list, &ctrl->Node );
+    ctrl->thread_switch = callout;
+
+    ctx->switch_control = ctrl + 1;
+  }
+}
 
-  if ( initial_extensions ) {
-    extension = (User_extensions_Control *)
+void _User_extensions_Handler_initialization(void)
+{
+  uint32_t number_of_initial_extensions =
+    rtems_configuration_get_number_of_initial_extensions();
+
+  if ( number_of_initial_extensions > 0 ) {
+    User_extensions_Switch_control *initial_extension_switch_controls =
       _Workspace_Allocate_or_fatal_error(
-        number_of_extensions * sizeof( User_extensions_Control )
+        number_of_initial_extensions
+          * sizeof( *initial_extension_switch_controls )
       );
+    User_extensions_Switch_context ctx = { initial_extension_switch_controls };
 
-    memset (
-      extension,
-      0,
-      number_of_extensions * sizeof( User_extensions_Control )
-    );
-
-    for ( i = 0 ; i < number_of_extensions ; i++ ) {
-      _User_extensions_Add_set_with_table (extension, &initial_extensions[i]);
-      extension++;
-    }
+    _User_extensions_Iterate( &ctx, _User_extensions_Switch_visitor );
   }
 }
-