Index: arch-utils.c
===================================================================
RCS file: /cvs/src/src/gdb/arch-utils.c,v
retrieving revision 1.204
diff -u -p -r1.204 arch-utils.c
--- arch-utils.c	8 Jun 2012 14:24:56 -0000	1.204
+++ arch-utils.c	14 Oct 2012 08:24:04 -0000
@@ -32,6 +32,7 @@
 #include "target-descriptions.h"
 #include "objfiles.h"
 #include "language.h"
+#include "observer.h"
 
 #include "version.h"
 
@@ -259,7 +260,7 @@ static const char *const endian_enum[] =
   endian_auto,
   NULL,
 };
-static const char *set_endian_string;
+static const char *endian_string;
 
 enum bfd_endian
 selected_byte_order (void)
@@ -274,14 +275,14 @@ show_endian (struct ui_file *file, int f
 	     const char *value)
 {
   if (target_byte_order_user == BFD_ENDIAN_UNKNOWN)
-    if (gdbarch_byte_order (get_current_arch ()) == BFD_ENDIAN_BIG)
+    if (strcmp (endian_string, endian_big) == 0)
       fprintf_unfiltered (file, _("The target endianness is set automatically "
 				  "(currently big endian)\n"));
     else
       fprintf_unfiltered (file, _("The target endianness is set automatically "
 				  "(currently little endian)\n"));
   else
-    if (target_byte_order_user == BFD_ENDIAN_BIG)
+    if (strcmp (endian_string, endian_big) == 0)
       fprintf_unfiltered (file,
 			  _("The target is assumed to be big endian\n"));
     else
@@ -296,14 +297,14 @@ set_endian (char *ignore_args, int from_
 
   gdbarch_info_init (&info);
 
-  if (set_endian_string == endian_auto)
+  if (endian_string == endian_auto)
     {
       target_byte_order_user = BFD_ENDIAN_UNKNOWN;
       if (! gdbarch_update_p (info))
 	internal_error (__FILE__, __LINE__,
 			_("set_endian: architecture update failed"));
     }
-  else if (set_endian_string == endian_little)
+  else if (endian_string == endian_little)
     {
       info.byte_order = BFD_ENDIAN_LITTLE;
       if (! gdbarch_update_p (info))
@@ -311,7 +312,7 @@ set_endian (char *ignore_args, int from_
       else
 	target_byte_order_user = BFD_ENDIAN_LITTLE;
     }
-  else if (set_endian_string == endian_big)
+  else if (endian_string == endian_big)
     {
       info.byte_order = BFD_ENDIAN_BIG;
       if (! gdbarch_update_p (info))
@@ -416,7 +417,7 @@ enum set_arch { set_arch_auto, set_arch_
 
 static const struct bfd_arch_info *target_architecture_user;
 
-static const char *set_architecture_string;
+static const char *architecture_string;
 
 const char *
 selected_architecture_name (void)
@@ -424,7 +425,7 @@ selected_architecture_name (void)
   if (target_architecture_user == NULL)
     return NULL;
   else
-    return set_architecture_string;
+    return architecture_string;
 }
 
 /* Called if the user enters ``show architecture'' without an
@@ -437,10 +438,10 @@ show_architecture (struct ui_file *file,
   if (target_architecture_user == NULL)
     fprintf_filtered (file, _("The target architecture is set "
 			      "automatically (currently %s)\n"),
-		      gdbarch_bfd_arch_info (get_current_arch ())->printable_name);
+		      architecture_string);
   else
     fprintf_filtered (file, _("The target architecture is assumed to be %s\n"),
-		      set_architecture_string);
+		      architecture_string);
 }
 
 
@@ -454,7 +455,7 @@ set_architecture (char *ignore_args, int
 
   gdbarch_info_init (&info);
 
-  if (strcmp (set_architecture_string, "auto") == 0)
+  if (strcmp (architecture_string, "auto") == 0)
     {
       target_architecture_user = NULL;
       if (!gdbarch_update_p (info))
@@ -463,7 +464,7 @@ set_architecture (char *ignore_args, int
     }
   else
     {
-      info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
+      info.bfd_arch_info = bfd_scan_arch (architecture_string);
       if (info.bfd_arch_info == NULL)
 	internal_error (__FILE__, __LINE__,
 			_("set_architecture: bfd_scan_arch failed"));
@@ -471,7 +472,7 @@ set_architecture (char *ignore_args, int
 	target_architecture_user = info.bfd_arch_info;
       else
 	printf_unfiltered (_("Architecture `%s' not recognized.\n"),
-			   set_architecture_string);
+			   architecture_string);
     }
   show_architecture (gdb_stdout, from_tty, NULL, NULL);
 }
@@ -579,6 +580,22 @@ static const bfd_target *default_bfd_vec
 
 static int default_byte_order = BFD_ENDIAN_UNKNOWN;
 
+static void
+set_endian_string (struct gdbarch *arch)
+{
+  if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG)
+    endian_string = endian_big;
+  else
+    endian_string = endian_little;
+}
+
+static void
+on_architecture_change (struct gdbarch *arch)
+{
+  architecture_string = gdbarch_bfd_arch_info (arch)->printable_name;
+  set_endian_string (arch);
+}
+
 void
 initialize_current_architecture (void)
 {
@@ -655,19 +672,26 @@ initialize_current_architecture (void)
   /* Create the ``set architecture'' command appending ``auto'' to the
      list of architectures.  */
   {
-    /* Append ``auto''.  */
     int nr;
+    struct gdbarch *arch = get_current_arch ();
+
+    /* Append ``auto''.  */
     for (nr = 0; arches[nr] != NULL; nr++);
     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
     arches[nr + 0] = "auto";
     arches[nr + 1] = NULL;
+
+    architecture_string = gdbarch_bfd_arch_info (arch)->printable_name;
+    set_endian_string (arch);
+
     add_setshow_enum_cmd ("architecture", class_support,
-			  arches, &set_architecture_string, 
+			  arches, &architecture_string, 
 			  _("Set architecture of target."),
 			  _("Show architecture of target."), NULL,
 			  set_architecture, show_architecture,
 			  &setlist, &showlist);
     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
+    observer_attach_architecture_changed (on_architecture_change);
   }
 }
 
@@ -813,7 +837,7 @@ void
 _initialize_gdbarch_utils (void)
 {
   add_setshow_enum_cmd ("endian", class_support,
-			endian_enum, &set_endian_string, 
+			endian_enum, &endian_string, 
 			_("Set endianness of target."),
 			_("Show endianness of target."),
 			NULL, set_endian, show_endian,
Index: testsuite/gdb.python/py-parameter.exp
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/gdb.python/py-parameter.exp,v
retrieving revision 1.6
diff -u -p -r1.6 py-parameter.exp
--- testsuite/gdb.python/py-parameter.exp	16 Jan 2012 16:21:52 -0000	1.6
+++ testsuite/gdb.python/py-parameter.exp	14 Oct 2012 08:24:04 -0000
@@ -26,6 +26,8 @@ gdb_reinitialize_dir $srcdir/$subdir
 # Skip all tests if Python scripting is not enabled.
 if { [skip_python_tests] } { continue }
 
+gdb_py_test_silent_cmd "python import sys" "Import sys" ""
+gdb_test "python print gdb.parameter ('endian') == sys.byteorder" "True"
 # We use "." here instead of ":" so that this works on win32 too.
 gdb_test "python print gdb.parameter ('directories')" "$srcdir/$subdir.\\\$cdir.\\\$cwd"