ARM: Implement WFE/WFI/SEV semantics.

[gem5.git] / src / sim / Root.py

diff --git a/src/sim/Root.py b/src/sim/Root.py
index fff998e0dea8b2fbf8c8ea85111b539e24836d0f..e15de155460b5c41634c52c521a032595d8e5472 100644 (file)
--- a/src/sim/Root.py
+++ b/src/sim/Root.py
@@ -1,4 +1,5 @@
 # Copyright (c) 2005-2007 The Regents of The University of Michigan
+# Copyright (c) 2010 Advanced Micro Devices, Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -28,7 +29,37 @@
 
 from m5.SimObject import SimObject
 from m5.params import *
+from m5.util import fatal
 
 class Root(SimObject):
+
+    _the_instance = None
+
+    def __new__(cls, **kwargs):
+        if Root._the_instance:
+            fatal("Attempt to allocate multiple instances of Root.")
+            return None
+
+        # first call: allocate the unique instance
+        #
+        # If SimObject ever implements __new__, we may want to pass
+        # kwargs here, but for now this goes straight to
+        # object.__new__ which prints an ugly warning if you pass it
+        # args.  Seems like a bad design but that's the way it is.
+        Root._the_instance = SimObject.__new__(cls)
+        return Root._the_instance
+        
+    @classmethod
+    def getInstance(cls):
+        return Root._the_instance
+
+    def path(self):
+        return 'root'
+
     type = 'Root'
-    dummy = Param.Int(0, "We don't support objects without params")
+
+    # Time syncing prevents the simulation from running faster than real time.
+    time_sync_enable = Param.Bool(False, "whether time syncing is enabled")
+    time_sync_period = Param.Clock("100ms", "how often to sync with real time")
+    time_sync_spin_threshold = \
+            Param.Clock("100us", "when less than this much time is left, spin")