diff -r 8bccb92a3503 -r 0347c75836a0 src/mem/slicc/ast/FormalParamAST.py
--- a/src/mem/slicc/ast/FormalParamAST.py	Fri Jul 10 11:20:14 2015 -0500
+++ b/src/mem/slicc/ast/FormalParamAST.py	Fri Jul 10 11:20:40 2015 -0500
@@ -56,6 +56,16 @@
            "interface" in type and (
                type["interface"] == "AbstractCacheEntry" or
                type["interface"] == "AbstractEntry")):
-            return type, "%s* %s" % (type.c_ident, param)
+            return type, "%s* %s" % (type.c_ident, param), False
+        elif self.default != None:
+            value = ""
+            if self.default == True:
+                value = "true"
+            elif self.default == False:
+                value = "false"
+            else:
+                value = "%s" % self.default
+            return type, "const %s& %s = %s" % (type.c_ident, param,
+                    value), True
         else:
-            return type, "const %s& %s" % (type.c_ident, param)
+            return type, "const %s& %s" % (type.c_ident, param), False
diff -r 8bccb92a3503 -r 0347c75836a0 src/mem/slicc/ast/FuncDeclAST.py
--- a/src/mem/slicc/ast/FuncDeclAST.py	Fri Jul 10 11:20:14 2015 -0500
+++ b/src/mem/slicc/ast/FuncDeclAST.py	Fri Jul 10 11:20:40 2015 -0500
@@ -46,6 +46,7 @@
     def generate(self, parent = None):
         types = []
         params = []
+        default_count = 0
         void_type = self.symtab.find("void", Type)
 
         # Generate definition code
@@ -58,9 +59,11 @@
         for formal in self.formals:
             # Lookup parameter types
             try:
-                type, ident = formal.generate()
+                type, ident, default = formal.generate()
                 types.append(type)
                 params.append(ident)
+                if default:
+                    default_count += 1
 
             except AttributeError:
                 types.append(formal.type)
@@ -76,7 +79,7 @@
 
         machine = self.state_machine
         func = Func(self.symtab, self.ident, self.location, return_type,
-                    types, params, str(body), self.pairs)
+                    types, params, str(body), self.pairs, default_count)
 
         if parent is not None:
             if not parent.addFunc(func):
diff -r 8bccb92a3503 -r 0347c75836a0 src/mem/slicc/symbols/Func.py
--- a/src/mem/slicc/symbols/Func.py	Fri Jul 10 11:20:14 2015 -0500
+++ b/src/mem/slicc/symbols/Func.py	Fri Jul 10 11:20:40 2015 -0500
@@ -30,7 +30,7 @@
 
 class Func(Symbol):
     def __init__(self, table, ident, location, return_type, param_types,
-                 param_strings, body, pairs):
+                 param_strings, body, pairs, default_count = 0):
         super(Func, self).__init__(table, ident, location, pairs)
         self.return_type = return_type
         self.param_types = param_types
@@ -39,6 +39,7 @@
         self.isInternalMachineFunc = False
         self.c_ident = ident
         self.class_name = ""
+        self.default_count = default_count
 
     def __repr__(self):
         return ""
@@ -58,14 +59,20 @@
         return "%s %s(%s);" % (return_type, self.c_ident,
                                ", ".join(self.param_strings))
 
+    @property
+    def numParamsWithDefaults(self):
+        return self.default_count
+
     def writeCodeFiles(self, path, includes):
         return
 
     def checkArguments(self, args):
-        if len(args) != len(self.param_types):
-            self.error("Wrong number of arguments passed to function : '%s'" +\
-                       " Expected %d, got %d", self.c_ident,
-                       len(self.param_types), len(args))
+        if len(args) + self.numParamsWithDefaults < len(self.param_types) or \
+           len(args) > len(self.param_types):
+            self.error("Wrong number of arguments passed to function: '%s'" + \
+                       " Expected at least: %d, got: %d", self.c_ident,
+                       len(self.param_types) - self.numParamsWithDefaults,
+                       len(args))
 
         cvec = []
         type_vec = []