scons: Hook up oldconfig and olddefconfig.

These two utilities help update an old config to add settings for new
config options. The difference between them is that oldconfig asks what
new settings you want to use, while olddefconfig automatically picks the
defaults.

Change-Id: Icd3e57f834684e620705beb884faa5b6e2cc7baa

SConstruct

@@ -264,6 +264,8 @@ kconfig_actions = (
     'guiconfig',
     'listnewconfig',
     'menuconfig',
+    'oldconfig',
+    'olddefconfig',
     'savedefconfig',
     'setconfig',
 )
@@ -317,6 +319,22 @@ Kconfig tools:
         scons menuconfig build/foo/bar
 
 
+        oldconfig:
+        Update an existing config by adding settings for new options. This is
+        the same as the olddefconfig tool, except it asks what values you want
+        for the new settings.
+
+        scons oldconfig build/foo/bar
+
+
+        olddefconfig:
+        Update an existing config by adding settings for new options. This is
+        the same as the oldconfig tool, except it uses the default for any new
+        setting.
+
+        scons olddefconfig build/foo/bar
+
+
         savedefconfig:
         Save a defconfig file which would give rise to the current config.
         For instance, you could use menuconfig to set up a config how you want
@@ -868,6 +886,11 @@ for variant_path in variant_paths:
         elif kconfig_action == 'menuconfig':
             kconfig.menuconfig(env, kconfig_file.abspath, config_file.abspath,
                     variant_path)
+        elif kconfig_action == 'oldconfig':
+            kconfig.oldconfig(env, kconfig_file.abspath, config_file.abspath)
+        elif kconfig_action == 'olddefconfig':
+            kconfig.olddefconfig(env, kconfig_file.abspath,
+                    config_file.abspath)
         elif kconfig_action == 'savedefconfig':
             if len(kconfig_args) != 1:
                 error('Usage: scons defconfig <build dir> <defconfig file>')

site_scons/gem5_scons/kconfig.py

@@ -33,6 +33,8 @@ _kconfig_helpers = {
     "GUICONFIG_PY": "guiconfig.py",
     "LISTNEWCONFIG_PY": "listnewconfig.py",
     "MENUCONFIG_PY": "menuconfig.py",
+    "OLDCONFIG_PY": "oldconfig.py",
+    "OLDDEFCONFIG_PY": "olddefconfig.py",
     "SAVEDEFCONFIG_PY": "savedefconfig.py",
     "SETCONFIG_PY": "setconfig.py",
 }
@@ -118,6 +120,24 @@ def listnewconfig(env, base_kconfig, config_path):
         error("Failed to run listnewconfig")
 
 
+def oldconfig(env, base_kconfig, config_path):
+    """
+    Interface of handling oldconfig.py of Kconfiglib
+    """
+    kconfig_env = _prep_env(env, base_kconfig, config_path)
+    if kconfig_env.Execute('"${OLDCONFIG_PY}" "${BASE_KCONFIG}"') != 0:
+        error("Failed to run oldconfig")
+
+
+def olddefconfig(env, base_kconfig, config_path):
+    """
+    Interface of handling olddefconfig.py of Kconfiglib
+    """
+    kconfig_env = _prep_env(env, base_kconfig, config_path)
+    if kconfig_env.Execute('"${OLDDEFCONFIG_PY}" "${BASE_KCONFIG}"') != 0:
+        error("Failed to run oldconfig")
+
+
 def menuconfig(
     env, base_kconfig, config_path, main_menu_text, style="aquatic"
 ):