i386: Move _CPU_Context_Initialize()

Update #2468.

cpukit/score/cpu/i386/cpu.c

@@ -114,6 +114,62 @@ void _CPU_Initialize(void)
 #endif
 }
 
+/*
+ * Stack alignment note:
+ *
+ * We want the stack to look to the '_entry_point' routine
+ * like an ordinary stack frame as if '_entry_point' was
+ * called from C-code.
+ * Note that '_entry_point' is jumped-to by the 'ret'
+ * instruction returning from _CPU_Context_switch() or
+ * _CPU_Context_restore() thus popping the _entry_point
+ * from the stack.
+ * However, _entry_point expects a frame to look like this:
+ *
+ *      args        [_Thread_Handler expects no args, however]
+ *      ------      (alignment boundary)
+ * SP-> return_addr return here when _entry_point returns which (never happens)
+ *
+ *
+ * Hence we must initialize the stack as follows
+ *
+ *         [arg1          ]:  n/a
+ *         [arg0 (aligned)]:  n/a
+ *         [ret. addr     ]:  NULL
+ * SP->    [jump-target   ]:  _entry_point
+ *
+ * When Context_switch returns it pops the _entry_point from
+ * the stack which then finds a standard layout.
+ */
+
+void _CPU_Context_Initialize(
+  Context_Control *the_context,
+  void *_stack_base,
+  size_t _size,
+  uint32_t _isr,
+  void (*_entry_point)( void ),
+  bool is_fp,
+  void *tls_area
+)
+{
+  uint32_t _stack;
+
+  (void) is_fp; /* avoid warning for being unused */
+
+  if ( _isr ) {
+    the_context->eflags = CPU_EFLAGS_INTERRUPTS_OFF;
+  } else {
+    the_context->eflags = CPU_EFLAGS_INTERRUPTS_ON;
+  }
+
+  _stack  = ((uint32_t)(_stack_base)) + (_size);
+  _stack &= ~ (CPU_STACK_ALIGNMENT - 1);
+  _stack -= 2*sizeof(proc_ptr*); /* see above for why we need to do this */
+  *((proc_ptr *)(_stack)) = (_entry_point);
+  the_context->ebp     = (void *) 0;
+  the_context->esp     = (void *) _stack;
+}
+
 uint32_t   _CPU_ISR_Get_level( void )
 {
   uint32_t   level;

cpukit/score/cpu/i386/rtems/score/cpu.h

@@ -433,52 +433,15 @@ uint32_t   _CPU_ISR_Get_level( void );
 
 #ifndef ASM
 
-/*
+void _CPU_Context_Initialize(
- * Stack alignment note:
+  Context_Control *the_context,
- *
+  void *stack_area_begin,
- * We want the stack to look to the '_entry_point' routine
+  size_t stack_area_size,
- * like an ordinary stack frame as if '_entry_point' was
+  uint32_t new_level,
- * called from C-code.
+  void (*entry_point)( void ),
- * Note that '_entry_point' is jumped-to by the 'ret'
+  bool is_fp,
- * instruction returning from _CPU_Context_switch() or
+  void *tls_area
- * _CPU_Context_restore() thus popping the _entry_point
+);
- * from the stack.
- * However, _entry_point expects a frame to look like this:
- *
- *      args        [_Thread_Handler expects no args, however]
- *      ------      (alignment boundary)
- * SP-> return_addr return here when _entry_point returns which (never happens)
- *
- *
- * Hence we must initialize the stack as follows
- *
- *         [arg1          ]:  n/a
- *         [arg0 (aligned)]:  n/a
- *         [ret. addr     ]:  NULL
- * SP->    [jump-target   ]:  _entry_point
- *
- * When Context_switch returns it pops the _entry_point from
- * the stack which then finds a standard layout.
- */
-
-
-
-#define _CPU_Context_Initialize( _the_context, _stack_base, _size, \
-                                   _isr, _entry_point, _is_fp, _tls_area ) \
-  do { \
-    uint32_t   _stack; \
-    \
-    (void) _is_fp; /* avoid warning for being unused */ \
-    if ( (_isr) ) (_the_context)->eflags = CPU_EFLAGS_INTERRUPTS_OFF; \
-    else          (_the_context)->eflags = CPU_EFLAGS_INTERRUPTS_ON; \
-    \
-    _stack  = ((uint32_t)(_stack_base)) + (_size); \
-	_stack &= ~ (CPU_STACK_ALIGNMENT - 1); \
-    _stack -= 2*sizeof(proc_ptr*); /* see above for why we need to do this */ \
-    *((proc_ptr *)(_stack)) = (_entry_point); \
-    (_the_context)->ebp     = (void *) 0; \
-    (_the_context)->esp     = (void *) _stack; \
-  } while (0)
 
 #define _CPU_Context_Restart_self( _the_context ) \
    _CPU_Context_restore( (_the_context) );