diff --git a/SConstruct b/SConstruct
index bfd93f26f..7a0bf2794 100644
--- a/SConstruct
+++ b/SConstruct
@@ -394,7 +394,7 @@ if main['GCC'] + main['SUNCC'] + main['ICC'] > 1:
 if main['GCC']:
     main.Append(CCFLAGS='-pipe')
     main.Append(CCFLAGS='-fno-strict-aliasing')
-    main.Append(CCFLAGS=Split('-Wall -Wno-sign-compare -Werror -Wundef'))
+    main.Append(CCFLAGS=['-Wall', '-Wno-sign-compare', '-Wundef'])
     main.Append(CXXFLAGS='-Wno-deprecated')
 elif main['ICC']:
     pass #Fix me... add warning flags once we clean up icc warnings
diff --git a/src/SConscript b/src/SConscript
index 20d454f03..d36f5f244 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -29,6 +29,7 @@
 # Authors: Nathan Binkert
 
 import array
+import bisect
 import imp
 import marshal
 import os
@@ -50,122 +51,144 @@ Export('env')
 
 build_env = dict([(opt, env[opt]) for opt in export_vars])
 
-def sort_list(_list):
-    """return a sorted copy of '_list'"""
-    if isinstance(_list, list):
-        _list = _list[:]
-    else:
-        _list = list(_list)
-    _list.sort()
-    return _list
+########################################################################
+# Code for adding source files of various types
+#
+class SourceMeta(type):
+    def __init__(cls, name, bases, dict):
+        super(SourceMeta, cls).__init__(name, bases, dict)
+        cls.all = []
+        
+    def get(cls, **kwargs):
+        for src in cls.all:
+            for attr,value in kwargs.iteritems():
+                if getattr(src, attr) != value:
+                    break
+            else:
+                yield src
 
-class PySourceFile(object):
+class SourceFile(object):
+    __metaclass__ = SourceMeta
+    def __init__(self, source):
+        tnode = source
+        if not isinstance(source, SCons.Node.FS.File):
+            tnode = File(source)
+
+        self.tnode = tnode
+        self.snode = tnode.srcnode()
+        self.filename = str(tnode)
+        self.dirname = dirname(self.filename)
+        self.basename = basename(self.filename)
+        index = self.basename.rfind('.')
+        if index <= 0:
+            # dot files aren't extensions
+            self.extname = self.basename, None
+        else:
+            self.extname = self.basename[:index], self.basename[index+1:]
+
+        for base in type(self).__mro__:
+            if issubclass(base, SourceFile):
+                bisect.insort_right(base.all, self)       
+
+    def __lt__(self, other): return self.filename < other.filename
+    def __le__(self, other): return self.filename <= other.filename
+    def __gt__(self, other): return self.filename > other.filename
+    def __ge__(self, other): return self.filename >= other.filename
+    def __eq__(self, other): return self.filename == other.filename
+    def __ne__(self, other): return self.filename != other.filename
+        
+class Source(SourceFile):
+    '''Add a c/c++ source file to the build'''
+    def __init__(self, source, Werror=True, swig=False, bin_only=False,
+                 skip_lib=False):
+        super(Source, self).__init__(source)
+
+        self.Werror = Werror
+        self.swig = swig
+        self.bin_only = bin_only
+        self.skip_lib = bin_only or skip_lib
+
+class PySource(SourceFile):
+    '''Add a python source file to the named package'''
     invalid_sym_char = re.compile('[^A-z0-9_]')
-    def __init__(self, package, tnode):
-        snode = tnode.srcnode()
-        filename = str(tnode)
-        pyname = basename(filename)
-        assert pyname.endswith('.py')
-        name = pyname[:-3]
+    modules = {}
+    tnodes = {}
+    symnames = {}
+    
+    def __init__(self, package, source):
+        super(PySource, self).__init__(source)
+
+        modname,ext = self.extname
+        assert ext == 'py'
+
         if package:
             path = package.split('.')
         else:
             path = []
 
         modpath = path[:]
-        if name != '__init__':
-            modpath += [name]
+        if modname != '__init__':
+            modpath += [ modname ]
         modpath = '.'.join(modpath)
 
-        arcpath = path + [ pyname ]
-        arcname = joinpath(*arcpath)
-
-        debugname = snode.abspath
+        arcpath = path + [ self.basename ]
+        debugname = self.snode.abspath
         if not exists(debugname):
-            debugname = tnode.abspath
+            debugname = self.tnode.abspath
 
-        self.tnode = tnode
-        self.snode = snode
-        self.pyname = pyname
         self.package = package
+        self.modname = modname
         self.modpath = modpath
-        self.arcname = arcname
+        self.arcname = joinpath(*arcpath)
         self.debugname = debugname
-        self.compiled = File(filename + 'c')
-        self.assembly = File(filename + '.s')
-        self.symname = "PyEMB_" + self.invalid_sym_char.sub('_', modpath)
-        
+        self.compiled = File(self.filename + 'c')
+        self.assembly = File(self.filename + '.s')
+        self.symname = "PyEMB_" + PySource.invalid_sym_char.sub('_', modpath)
 
-########################################################################
-# Code for adding source files of various types
-#
-cc_lib_sources = []
-def Source(source):
-    '''Add a source file to the libm5 build'''
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
+        PySource.modules[modpath] = self
+        PySource.tnodes[self.tnode] = self
+        PySource.symnames[self.symname] = self
 
-    cc_lib_sources.append(source)
-
-cc_bin_sources = []
-def BinSource(source):
-    '''Add a source file to the m5 binary build'''
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
-
-    cc_bin_sources.append(source)
-
-py_sources = []
-def PySource(package, source):
-    '''Add a python source file to the named package'''
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
-
-    source = PySourceFile(package, source)
-    py_sources.append(source)
-
-sim_objects_fixed = False
-sim_object_modfiles = set()
-def SimObject(source):
+class SimObject(PySource):
     '''Add a SimObject python file as a python source object and add
     it to a list of sim object modules'''
 
-    if sim_objects_fixed:
-        raise AttributeError, "Too late to call SimObject now."
+    fixed = False
+    modnames = []
 
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
+    def __init__(self, source):
+        super(SimObject, self).__init__('m5.objects', source)
+        if self.fixed:
+            raise AttributeError, "Too late to call SimObject now."
 
-    PySource('m5.objects', source)
-    modfile = basename(str(source))
-    assert modfile.endswith('.py')
-    modname = modfile[:-3]
-    sim_object_modfiles.add(modname)
+        bisect.insort_right(SimObject.modnames, self.modname)
 
-swig_sources = []
-def SwigSource(package, source):
+class SwigSource(SourceFile):
     '''Add a swig file to build'''
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
-    val = source,package
-    swig_sources.append(val)
+
+    def __init__(self, package, source):
+        super(SwigSource, self).__init__(source)
+
+        modname,ext = self.extname
+        assert ext == 'i'
+
+        self.module = modname
+        cc_file = joinpath(self.dirname, modname + '_wrap.cc')
+        py_file = joinpath(self.dirname, modname + '.py')
+
+        self.cc_source = Source(cc_file, swig=True)
+        self.py_source = PySource(package, py_file)
 
 unit_tests = []
 def UnitTest(target, sources):
     if not isinstance(sources, (list, tuple)):
         sources = [ sources ]
-    
-    srcs = []
-    for source in sources:
-        if not isinstance(source, SCons.Node.FS.File):
-            source = File(source)
-        srcs.append(source)
-            
-    unit_tests.append((target, srcs))
+
+    sources = [ Source(src, skip_lib=True) for src in sources ]
+    unit_tests.append((target, sources))
 
 # Children should have access
 Export('Source')
-Export('BinSource')
 Export('PySource')
 Export('SimObject')
 Export('SwigSource')
@@ -276,7 +299,8 @@ class DictImporter(object):
         if fullname.startswith('m5.internal'):
             return None
 
-        if fullname in self.modules and exists(self.modules[fullname]):
+        source = self.modules.get(fullname, None)
+        if source is not None and exists(source.snode.abspath):
             return self
 
         return None
@@ -295,34 +319,28 @@ class DictImporter(object):
             mod.__dict__['buildEnv'] = build_env
             return mod
 
-        srcfile = self.modules[fullname]
-        if basename(srcfile) == '__init__.py':
-            mod.__path__ = fullname.split('.')
-        mod.__file__ = srcfile
+        source = self.modules[fullname]
+        if source.modname == '__init__':
+            mod.__path__ = source.modpath
+        mod.__file__ = source.snode.abspath
 
-        exec file(srcfile, 'r') in mod.__dict__
+        exec file(source.snode.abspath, 'r') in mod.__dict__
 
         return mod
 
-py_modules = {}
-for source in py_sources:
-    py_modules[source.modpath] = source.snode.abspath
-
 # install the python importer so we can grab stuff from the source
 # tree itself.  We can't have SimObjects added after this point or
 # else we won't know about them for the rest of the stuff.
-sim_objects_fixed = True
-importer = DictImporter(py_modules)
+SimObject.fixed = True
+importer = DictImporter(PySource.modules)
 sys.meta_path[0:0] = [ importer ]
 
 import m5
 
 # import all sim objects so we can populate the all_objects list
 # make sure that we're working with a list, then let's sort it
-sim_objects = list(sim_object_modfiles)
-sim_objects.sort()
-for simobj in sim_objects:
-    exec('from m5.objects import %s' % simobj)
+for modname in SimObject.modnames:
+    exec('from m5.objects import %s' % modname)
 
 # we need to unload all of the currently imported modules so that they
 # will be re-imported the next time the sconscript is run
@@ -333,7 +351,7 @@ sim_objects = m5.SimObject.allClasses
 all_enums = m5.params.allEnums
 
 all_params = {}
-for name,obj in sim_objects.iteritems():
+for name,obj in sorted(sim_objects.iteritems()):
     for param in obj._params.local.values():
         if not hasattr(param, 'swig_decl'):
             continue
@@ -346,7 +364,7 @@ for name,obj in sim_objects.iteritems():
 # calculate extra dependencies
 #
 module_depends = ["m5", "m5.SimObject", "m5.params"]
-depends = [ File(py_modules[dep]) for dep in module_depends ]
+depends = [ PySource.modules[dep].tnode for dep in module_depends ]
 
 ########################################################################
 #
@@ -392,7 +410,7 @@ def makeObjectsInitFile(target, source, env):
 
 # Generate an __init__.py file for the objects package
 env.Command('python/m5/objects/__init__.py',
-            [ Value(o) for o in sort_list(sim_object_modfiles) ],
+            map(Value, SimObject.modnames),
             makeObjectsInitFile)
 PySource('m5.objects', 'python/m5/objects/__init__.py')
 
@@ -409,6 +427,7 @@ def createSimObjectParam(target, source, env):
     obj = sim_objects[name]
 
     print >>hh_file, obj.cxx_decl()
+    hh_file.close()
 
 def createSwigParam(target, source, env):
     assert len(target) == 1 and len(source) == 1
@@ -419,6 +438,7 @@ def createSwigParam(target, source, env):
 
     for line in param.swig_decl():
         print >>i_file, line
+    i_file.close()
 
 def createEnumStrings(target, source, env):
     assert len(target) == 1 and len(source) == 1
@@ -438,11 +458,13 @@ def createEnumParam(target, source, env):
     obj = all_enums[name]
 
     print >>hh_file, obj.cxx_decl()
+    hh_file.close()
 
 # Generate all of the SimObject param struct header files
 params_hh_files = []
-for name,simobj in sim_objects.iteritems():
-    extra_deps = [ File(py_modules[simobj.__module__]) ]
+for name,simobj in sorted(sim_objects.iteritems()):
+    py_source = PySource.modules[simobj.__module__]
+    extra_deps = [ py_source.tnode ]
 
     hh_file = File('params/%s.hh' % name)
     params_hh_files.append(hh_file)
@@ -463,8 +485,9 @@ for name,param in all_params.iteritems():
     env.Depends(i_file, depends)
 
 # Generate all enum header files
-for name,enum in all_enums.iteritems():
-    extra_deps = [ File(py_modules[enum.__module__]) ]
+for name,enum in sorted(all_enums.iteritems()):
+    py_source = PySource.modules[enum.__module__]
+    extra_deps = [ py_source.tnode ]
 
     cc_file = File('enums/%s.cc' % name)
     env.Command(cc_file, Value(name), createEnumStrings)
@@ -576,32 +599,18 @@ def buildParams(target, source, env):
         print >>out, '%%include "params/%s.hh"' % obj
 
 params_file = File('params/params.i')
-names = sort_list(sim_objects.keys())
-env.Command(params_file, [ Value(v) for v in names ], buildParams)
+names = sorted(sim_objects.keys())
+env.Command(params_file, map(Value, names), buildParams)
 env.Depends(params_file, params_hh_files + params_i_files + depends)
 SwigSource('m5.objects', params_file)
 
 # Build all swig modules
-swig_modules = []
-cc_swig_sources = []
-for source,package in swig_sources:
-    filename = str(source)
-    assert filename.endswith('.i')
-
-    base = '.'.join(filename.split('.')[:-1])
-    module = basename(base)
-    cc_file = base + '_wrap.cc'
-    py_file = base + '.py'
-
-    env.Command([cc_file, py_file], source,
+for swig in SwigSource.all:
+    env.Command([swig.cc_source.tnode, swig.py_source.tnode], swig.tnode,
                 '$SWIG $SWIGFLAGS -outdir ${TARGETS[1].dir} '
                 '-o ${TARGETS[0]} $SOURCES')
-    env.Depends(py_file, source)
-    env.Depends(cc_file, source)
-
-    swig_modules.append(Value(module))
-    cc_swig_sources.append(File(cc_file))
-    PySource(package, py_file)
+    env.Depends(swig.py_source.tnode, swig.tnode)
+    env.Depends(swig.cc_source.tnode, swig.tnode)
 
 # Generate the main swig init file
 def makeSwigInit(target, source, env):
@@ -616,7 +625,9 @@ def makeSwigInit(target, source, env):
     print >>f, '}'
     f.close()
 
-env.Command('python/swig/init.cc', swig_modules, makeSwigInit)
+env.Command('python/swig/init.cc',
+            map(Value, sorted(s.module for s in SwigSource.all)),
+            makeSwigInit)
 Source('python/swig/init.cc')
 
 # Generate traceflags.py
@@ -813,7 +824,7 @@ extern const Flags *compoundFlags[];
 
     f.close()
 
-flags = [ Value(f) for f in trace_flags.values() ]
+flags = map(Value, trace_flags.values())
 env.Command('base/traceflags.py', flags, traceFlagsPy)
 PySource('m5', 'base/traceflags.py')
 
@@ -827,10 +838,6 @@ Source('base/traceflags.cc')
 # byte code, compress it, and then generate an assembly file that
 # inserts the result into the data section with symbols indicating the
 # beginning, and end (and with the size at the end)
-py_sources_tnodes = {}
-for pysource in py_sources:
-    py_sources_tnodes[pysource.tnode] = pysource
-
 def objectifyPyFile(target, source, env):
     '''Action function to compile a .py into a code object, marshal
     it, compress it, and stick it into an asm file so the code appears
@@ -839,7 +846,7 @@ def objectifyPyFile(target, source, env):
     src = file(str(source[0]), 'r').read()
     dst = file(str(target[0]), 'w')
 
-    pysource = py_sources_tnodes[source[0]]
+    pysource = PySource.tnodes[source[0]]
     compiled = compile(src, pysource.debugname, 'exec')
     marshalled = marshal.dumps(compiled)
     compressed = zlib.compress(marshalled)
@@ -864,7 +871,7 @@ def objectifyPyFile(target, source, env):
     print >>dst, "%s_end:" % sym
     print >>dst, ".long %d" % len(marshalled)
 
-for source in py_sources:
+for source in PySource.all:
     env.Command(source.assembly, source.tnode, objectifyPyFile)
     Source(source.assembly)
 
@@ -873,14 +880,11 @@ for source in py_sources:
 # contains information about the importer that python uses to get at
 # the embedded files, and then there's a list of all of the rest that
 # the importer uses to load the rest on demand.
-py_sources_symbols = {}
-for pysource in py_sources:
-    py_sources_symbols[pysource.symname] = pysource
 def pythonInit(target, source, env):
     dst = file(str(target[0]), 'w')
 
     def dump_mod(sym, endchar=','):
-        pysource = py_sources_symbols[sym]
+        pysource = PySource.symnames[sym]
         print >>dst, '    { "%s",' % pysource.arcname
         print >>dst, '      "%s",' % pysource.modpath
         print >>dst, '       %s_beg, %s_end,' % (sym, sym)
@@ -907,8 +911,10 @@ def pythonInit(target, source, env):
     print >>dst, "    { 0, 0, 0, 0, 0, 0 }"
     print >>dst, "};"
 
-symbols = [Value(s.symname) for s in py_sources]
-env.Command('sim/init_python.cc', symbols, pythonInit)
+
+env.Command('sim/init_python.cc',
+            map(Value, (s.symname for s in PySource.all)),
+            pythonInit)
 Source('sim/init_python.cc')
 
 ########################################################################
@@ -920,26 +926,7 @@ Source('sim/init_python.cc')
 # List of constructed environments to pass back to SConstruct
 envList = []
 
-# This function adds the specified sources to the given build
-# environment, and returns a list of all the corresponding SCons
-# Object nodes (including an extra one for date.cc).  We explicitly
-# add the Object nodes so we can set up special dependencies for
-# date.cc.
-def make_objs(sources, env, static):
-    if static:
-        XObject = env.StaticObject
-    else:
-        XObject = env.SharedObject
-
-    objs = [ XObject(s) for s in sources ]
-  
-    # make date.cc depend on all other objects so it always gets
-    # recompiled whenever anything else does
-    date_obj = XObject('base/date.cc')
-
-    env.Depends(date_obj, objs)
-    objs.append(date_obj)
-    return objs
+date_source = Source('base/date.cc', skip_lib=True)
 
 # Function to create a new build environment as clone of current
 # environment 'env' with modified object suffix and optional stripped
@@ -956,15 +943,45 @@ def makeEnv(label, objsfx, strip = False, **kwargs):
     new_env.Append(**kwargs)
 
     swig_env = new_env.Clone()
+    swig_env.Append(CCFLAGS='-Werror')
     if env['GCC']:
         swig_env.Append(CCFLAGS='-Wno-uninitialized')
         swig_env.Append(CCFLAGS='-Wno-sign-compare')
         swig_env.Append(CCFLAGS='-Wno-parentheses')
 
-    static_objs = make_objs(cc_lib_sources, new_env, static=True)
-    shared_objs = make_objs(cc_lib_sources, new_env, static=False)
-    static_objs += [ swig_env.StaticObject(s) for s in cc_swig_sources ]
-    shared_objs += [ swig_env.SharedObject(s) for s in cc_swig_sources ]
+    werror_env = new_env.Clone()
+    werror_env.Append(CCFLAGS='-Werror')
+
+    def make_obj(source, static, extra_deps = None):
+        '''This function adds the specified source to the correct
+        build environment, and returns the corresponding SCons Object
+        nodes'''
+
+        if source.swig:
+            env = swig_env
+        elif source.Werror:
+            env = werror_env
+        else:
+            env = new_env
+
+        if static:
+            obj = env.StaticObject(source.tnode)
+        else:
+            obj = env.SharedObject(source.tnode)
+
+        if extra_deps:
+            env.Depends(obj, extra_deps)
+
+        return obj
+
+    static_objs = [ make_obj(s, True) for s in Source.get(skip_lib=False)]
+    shared_objs = [ make_obj(s, False) for s in Source.get(skip_lib=False)]
+
+    static_date = make_obj(date_source, static=True, extra_deps=static_objs)
+    static_objs.append(static_date)
+    
+    shared_date = make_obj(date_source, static=False, extra_deps=shared_objs)
+    shared_objs.append(static_date)
 
     # First make a library of everything but main() so other programs can
     # link against m5.
@@ -972,21 +989,23 @@ def makeEnv(label, objsfx, strip = False, **kwargs):
     shared_lib = new_env.SharedLibrary(libname, shared_objs)
 
     for target, sources in unit_tests:
-        objs = [ new_env.StaticObject(s) for s in sources ]
+        objs = [ make_obj(s, static=True) for s in sources ]
         new_env.Program("unittest/%s.%s" % (target, label), objs + static_objs)
 
     # Now link a stub with main() and the static library.
-    objects = [new_env.Object(s) for s in cc_bin_sources] + static_objs
+    bin_objs = [make_obj(s, True) for s in Source.get(bin_only=True) ]
+    progname = exename
+    if strip:
+        progname += '.unstripped'
+
+    targets = new_env.Program(progname, bin_objs + static_objs)
+
     if strip:
-        unstripped_exe = exename + '.unstripped'
-        new_env.Program(unstripped_exe, objects)
         if sys.platform == 'sunos5':
             cmd = 'cp $SOURCE $TARGET; strip $TARGET'
         else:
             cmd = 'strip $SOURCE -o $TARGET'
-        targets = new_env.Command(exename, unstripped_exe, cmd)
-    else:
-        targets = new_env.Program(exename, objects)
+        targets = new_env.Command(exename, progname, cmd)
             
     new_env.M5Binary = targets[0]
     envList.append(new_env)
diff --git a/src/arch/x86/faults.cc b/src/arch/x86/faults.cc
index bef7e4414..10b539248 100644
--- a/src/arch/x86/faults.cc
+++ b/src/arch/x86/faults.cc
@@ -271,12 +271,8 @@ namespace X86ISA
         tc->setMiscReg(MISCREG_DR6, 0x00000000ffff0ff0ULL);
         tc->setMiscReg(MISCREG_DR7, 0x0000000000000400ULL);
 
-        // We're now in real mode, effectively at CPL 0
-        HandyM5Reg m5Reg = 0;
-        m5Reg.mode = LegacyMode;
-        m5Reg.submode = RealMode;
-        m5Reg.cpl = 0;
-        tc->setMiscReg(MISCREG_M5_REG, m5Reg);
+        // Update the handy M5 Reg.
+        tc->setMiscReg(MISCREG_M5_REG, 0);
         MicroPC entry = X86ISAInst::RomLabels::extern_label_initIntHalt;
         tc->setMicroPC(romMicroPC(entry));
         tc->setNextMicroPC(romMicroPC(entry) + 1);
@@ -289,7 +285,7 @@ namespace X86ISA
         HandyM5Reg m5Reg = tc->readMiscReg(MISCREG_M5_REG);
         if (m5Reg.mode != LegacyMode || m5Reg.submode != RealMode) {
             panic("Startup IPI recived outside of real mode. "
-                    "Don't know what to do.");
+                    "Don't know what to do. %d, %d", m5Reg.mode, m5Reg.submode);
         }
 
         tc->setMiscReg(MISCREG_CS, vector << 8);
diff --git a/src/arch/x86/miscregfile.cc b/src/arch/x86/miscregfile.cc
index 0316603e5..317cdadc5 100644
--- a/src/arch/x86/miscregfile.cc
+++ b/src/arch/x86/miscregfile.cc
@@ -96,6 +96,64 @@ using namespace std;
 
 class Checkpoint;
 
+void MiscRegFile::updateHandyM5Reg(Efer efer, CR0 cr0,
+        SegAttr csAttr, SegAttr ssAttr, RFLAGS rflags)
+{
+    HandyM5Reg m5reg;
+    if (efer.lma) {
+        m5reg.mode = LongMode;
+        if (csAttr.longMode)
+            m5reg.submode = SixtyFourBitMode;
+        else
+            m5reg.submode = CompatabilityMode;
+    } else {
+        m5reg.mode = LegacyMode;
+        if (cr0.pe) {
+            if (rflags.vm)
+                m5reg.submode = Virtual8086Mode;
+            else
+                m5reg.submode = ProtectedMode;
+        } else {
+            m5reg.submode = RealMode;
+        }
+    }
+    m5reg.cpl = csAttr.dpl;
+    m5reg.paging = cr0.pg;
+    m5reg.prot = cr0.pe;
+
+    // Compute the default and alternate operand size.
+    if (m5reg.submode == SixtyFourBitMode || csAttr.defaultSize) {
+        m5reg.defOp = 2;
+        m5reg.altOp = 1;
+    } else {
+        m5reg.defOp = 1;
+        m5reg.altOp = 2;
+    }
+
+    // Compute the default and alternate address size.
+    if (m5reg.submode == SixtyFourBitMode) {
+        m5reg.defAddr = 3;
+        m5reg.altAddr = 2;
+    } else if (csAttr.defaultSize) {
+        m5reg.defAddr = 2;
+        m5reg.altAddr = 1;
+    } else {
+        m5reg.defAddr = 1;
+        m5reg.altAddr = 2;
+    }
+
+    // Compute the stack size
+    if (m5reg.submode == SixtyFourBitMode) {
+        m5reg.stack = 3;
+    } else if (ssAttr.defaultSize) {
+        m5reg.stack = 2;
+    } else {
+        m5reg.stack = 1;
+    }
+
+    regVal[MISCREG_M5_REG] = m5reg;
+}
+
 void MiscRegFile::clear()
 {
     // Blank everything. 0 might not be an appropriate value for some things,
@@ -151,39 +209,17 @@ void MiscRegFile::setReg(MiscRegIndex miscReg,
             CR0 toggled = regVal[miscReg] ^ val;
             CR0 newCR0 = val;
             Efer efer = regVal[MISCREG_EFER];
-            HandyM5Reg m5reg = regVal[MISCREG_M5_REG];
             if (toggled.pg && efer.lme) {
                 if (newCR0.pg) {
                     //Turning on long mode
                     efer.lma = 1;
-                    m5reg.mode = LongMode;
                     regVal[MISCREG_EFER] = efer;
                 } else {
                     //Turning off long mode
                     efer.lma = 0;
-                    m5reg.mode = LegacyMode;
                     regVal[MISCREG_EFER] = efer;
                 }
             }
-            // Figure out what submode we're in.
-            if (m5reg.mode == LongMode) {
-                SegAttr csAttr = regVal[MISCREG_CS_ATTR];
-                if (csAttr.longMode)
-                    m5reg.submode = SixtyFourBitMode;
-                else
-                    m5reg.submode = CompatabilityMode;
-            } else {
-                if (newCR0.pe) {
-                    RFLAGS rflags = regVal[MISCREG_RFLAGS];
-                    if (rflags.vm)
-                        m5reg.submode = Virtual8086Mode;
-                    else
-                        m5reg.submode = ProtectedMode;
-                } else {
-                    m5reg.submode = RealMode;
-                }
-            }
-            regVal[MISCREG_M5_REG] = m5reg;
             if (toggled.pg) {
                 tc->getITBPtr()->invalidateAll();
                 tc->getDTBPtr()->invalidateAll();
@@ -191,6 +227,11 @@ void MiscRegFile::setReg(MiscRegIndex miscReg,
             //This must always be 1.
             newCR0.et = 1;
             newVal = newCR0;
+            updateHandyM5Reg(regVal[MISCREG_EFER],
+                             newCR0,
+                             regVal[MISCREG_CS_ATTR],
+                             regVal[MISCREG_SS_ATTR],
+                             regVal[MISCREG_RFLAGS]);
         }
         break;
       case MISCREG_CR2:
@@ -214,28 +255,33 @@ void MiscRegFile::setReg(MiscRegIndex miscReg,
         {
             SegAttr toggled = regVal[miscReg] ^ val;
             SegAttr newCSAttr = val;
-            HandyM5Reg m5reg = regVal[MISCREG_M5_REG];
             if (toggled.longMode) {
                 if (newCSAttr.longMode) {
-                    if (m5reg.mode == LongMode)
-                        m5reg.submode = SixtyFourBitMode;
                     regVal[MISCREG_ES_EFF_BASE] = 0;
                     regVal[MISCREG_CS_EFF_BASE] = 0;
                     regVal[MISCREG_SS_EFF_BASE] = 0;
                     regVal[MISCREG_DS_EFF_BASE] = 0;
                 } else {
-                    if (m5reg.mode == LongMode)
-                        m5reg.submode = CompatabilityMode;
                     regVal[MISCREG_ES_EFF_BASE] = regVal[MISCREG_ES_BASE];
                     regVal[MISCREG_CS_EFF_BASE] = regVal[MISCREG_CS_BASE];
                     regVal[MISCREG_SS_EFF_BASE] = regVal[MISCREG_SS_BASE];
                     regVal[MISCREG_DS_EFF_BASE] = regVal[MISCREG_DS_BASE];
                 }
             }
-            m5reg.cpl = newCSAttr.dpl;
-            regVal[MISCREG_M5_REG] = m5reg;
+            updateHandyM5Reg(regVal[MISCREG_EFER],
+                             regVal[MISCREG_CR0],
+                             newCSAttr,
+                             regVal[MISCREG_SS_ATTR],
+                             regVal[MISCREG_RFLAGS]);
         }
         break;
+      case MISCREG_SS_ATTR:
+        updateHandyM5Reg(regVal[MISCREG_EFER],
+                         regVal[MISCREG_CR0],
+                         regVal[MISCREG_CS_ATTR],
+                         val,
+                         regVal[MISCREG_RFLAGS]);
+        break;
       // These segments always actually use their bases, or in other words
       // their effective bases must stay equal to their actual bases.
       case MISCREG_FS_BASE:
@@ -333,6 +379,16 @@ void MiscRegFile::setReg(MiscRegIndex miscReg,
             dr7.len3 = newDR7.len3;
         }
         break;
+      case MISCREG_M5_REG:
+        // Writing anything to the m5reg with side effects makes it update
+        // based on the current values of the relevant registers. The actual
+        // value written is discarded.
+        updateHandyM5Reg(regVal[MISCREG_EFER],
+                         regVal[MISCREG_CR0],
+                         regVal[MISCREG_CS_ATTR],
+                         regVal[MISCREG_SS_ATTR],
+                         regVal[MISCREG_RFLAGS]);
+        return;
       default:
         break;
     }
diff --git a/src/arch/x86/miscregfile.hh b/src/arch/x86/miscregfile.hh
index 6d3ae4e92..babc65b44 100644
--- a/src/arch/x86/miscregfile.hh
+++ b/src/arch/x86/miscregfile.hh
@@ -107,6 +107,8 @@ namespace X86ISA
     {
       protected:
         MiscReg regVal[NumMiscRegs];
+        void updateHandyM5Reg(Efer efer, CR0 cr0,
+                SegAttr csAttr, SegAttr ssAttr, RFLAGS rflags);
 
       public:
         void clear();
diff --git a/src/arch/x86/miscregs.hh b/src/arch/x86/miscregs.hh
index af02e9422..088dbeace 100644
--- a/src/arch/x86/miscregs.hh
+++ b/src/arch/x86/miscregs.hh
@@ -518,6 +518,13 @@ namespace X86ISA
         Bitfield<0> mode;
         Bitfield<3, 1> submode;
         Bitfield<5, 4> cpl;
+        Bitfield<6> paging;
+        Bitfield<7> prot;
+        Bitfield<9, 8> defOp;
+        Bitfield<11, 10> altOp;
+        Bitfield<13, 12> defAddr;
+        Bitfield<15, 14> altAddr;
+        Bitfield<17, 16> stack;
     EndBitUnion(HandyM5Reg)
 
     /**
diff --git a/src/arch/x86/predecoder.cc b/src/arch/x86/predecoder.cc
index 620ab89ea..5bac8e711 100644
--- a/src/arch/x86/predecoder.cc
+++ b/src/arch/x86/predecoder.cc
@@ -80,9 +80,9 @@ namespace X86ISA
 
         emi.modRM = 0;
         emi.sib = 0;
-        HandyM5Reg m5reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
-        emi.mode.mode = m5reg.mode;
-        emi.mode.submode = m5reg.submode;
+        m5Reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
+        emi.mode.mode = m5Reg.mode;
+        emi.mode.submode = m5Reg.submode;
     }
 
     void Predecoder::process()
@@ -216,34 +216,15 @@ namespace X86ISA
             DPRINTF(Predecoder, "Found opcode %#x.\n", nextByte);
             emi.opcode.op = nextByte;
 
-            SegAttr csAttr = tc->readMiscRegNoEffect(MISCREG_CS_ATTR);
-
             //Figure out the effective operand size. This can be overriden to
             //a fixed value at the decoder level.
             int logOpSize;
-            if (emi.mode.submode == SixtyFourBitMode)
-            {
-                if(emi.rex.w)
-                    logOpSize = 3; // 64 bit operand size
-                else if(emi.legacy.op)
-                    logOpSize = 1; // 16 bit operand size
-                else
-                    logOpSize = 2; // 32 bit operand size
-            }
-            else if(csAttr.defaultSize)
-            {
-                if(emi.legacy.op)
-                    logOpSize = 1; // 16 bit operand size
-                else
-                    logOpSize = 2; // 32 bit operand size
-            }
-            else // 16 bit default operand size
-            {
-                if(emi.legacy.op)
-                    logOpSize = 2; // 32 bit operand size
-                else
-                    logOpSize = 1; // 16 bit operand size
-            }
+            if (emi.rex.w)
+                logOpSize = 3; // 64 bit operand size
+            else if (emi.legacy.op)
+                logOpSize = m5Reg.altOp;
+            else
+                logOpSize = m5Reg.defOp;
 
             //Set the actual op size
             emi.opSize = 1 << logOpSize;
@@ -251,41 +232,18 @@ namespace X86ISA
             //Figure out the effective address size. This can be overriden to
             //a fixed value at the decoder level.
             int logAddrSize;
-            if(emi.mode.submode == SixtyFourBitMode)
-            {
-                if(emi.legacy.addr)
-                    logAddrSize = 2; // 32 bit address size
-                else
-                    logAddrSize = 3; // 64 bit address size
-            }
-            else if(csAttr.defaultSize)
-            {
-                if(emi.legacy.addr)
-                    logAddrSize = 1; // 16 bit address size
-                else
-                    logAddrSize = 2; // 32 bit address size
-            }
-            else // 16 bit default operand size
-            {
-                if(emi.legacy.addr)
-                    logAddrSize = 2; // 32 bit address size
-                else
-                    logAddrSize = 1; // 16 bit address size
-            }
-
-            SegAttr ssAttr = tc->readMiscRegNoEffect(MISCREG_SS_ATTR);
-            //Figure out the effective stack width. This can be overriden to
-            //a fixed value at the decoder level.
-            if(emi.mode.submode == SixtyFourBitMode)
-                emi.stackSize = 8; // 64 bit stack width
-            else if(ssAttr.defaultSize)
-                emi.stackSize = 4; // 32 bit stack width
+            if(emi.legacy.addr)
+                logAddrSize = m5Reg.altAddr;
             else
-                emi.stackSize = 2; // 16 bit stack width
+                logAddrSize = m5Reg.defAddr;
 
             //Set the actual address size
             emi.addrSize = 1 << logAddrSize;
 
+            //Figure out the effective stack width. This can be overriden to
+            //a fixed value at the decoder level.
+            emi.stackSize = 1 << m5Reg.stack;
+
             //Figure out how big of an immediate we'll retreive based
             //on the opcode.
             int immType = ImmediateType[emi.opcode.num - 1][nextByte];
@@ -318,9 +276,7 @@ namespace X86ISA
         ModRM modRM;
         modRM = nextByte;
         DPRINTF(Predecoder, "Found modrm byte %#x.\n", nextByte);
-        SegAttr csAttr = tc->readMiscRegNoEffect(MISCREG_CS_ATTR);
-        if (emi.mode.submode != SixtyFourBitMode &&
-                !csAttr.defaultSize) {
+        if (m5Reg.defOp == 1) {
             //figure out 16 bit displacement size
             if ((modRM.mod == 0 && modRM.rm == 6) || modRM.mod == 2)
                 displacementSize = 2;
diff --git a/src/arch/x86/predecoder.hh b/src/arch/x86/predecoder.hh
index a16ce6fb8..4893f1de9 100644
--- a/src/arch/x86/predecoder.hh
+++ b/src/arch/x86/predecoder.hh
@@ -61,6 +61,7 @@
 #include <cassert>
 
 #include "arch/x86/types.hh"
+#include "arch/x86/miscregs.hh"
 #include "base/bitfield.hh"
 #include "base/misc.hh"
 #include "base/trace.hh"
@@ -91,10 +92,11 @@ namespace X86ISA
         int offset;
         //The extended machine instruction being generated
         ExtMachInst emi;
+        HandyM5Reg m5Reg;
 
         inline uint8_t getNextByte()
         {
-            return (fetchChunk >> (offset * 8)) & 0xff;
+            return ((uint8_t *)&fetchChunk)[offset];
         }
 
         void getImmediate(int &collected, uint64_t &current, int size)
@@ -182,6 +184,7 @@ namespace X86ISA
         {
             emi.mode.mode = LongMode;
             emi.mode.submode = SixtyFourBitMode;
+            m5Reg = 0;
         }
 
         void reset()
diff --git a/src/arch/x86/process.cc b/src/arch/x86/process.cc
index 43dd4a591..f7b5468b4 100644
--- a/src/arch/x86/process.cc
+++ b/src/arch/x86/process.cc
@@ -232,6 +232,15 @@ X86_64LiveProcess::startup()
 
         tc->setMiscRegNoEffect(MISCREG_CS_ATTR, csAttr);
 
+        Efer efer = 0;
+        efer.sce = 1; // Enable system call extensions.
+        efer.lme = 1; // Enable long mode.
+        efer.lma = 1; // Activate long mode.
+        efer.nxe = 1; // Enable nx support.
+        efer.svme = 0; // Disable svm support for now. It isn't implemented.
+        efer.ffxsr = 1; // Turn on fast fxsave and fxrstor.
+        tc->setMiscReg(MISCREG_EFER, efer);
+
         //Set up the registers that describe the operating mode.
         CR0 cr0 = 0;
         cr0.pg = 1; // Turn on paging.
@@ -248,15 +257,6 @@ X86_64LiveProcess::startup()
                     // setting it to one.
         cr0.pe = 1; // We're definitely in protected mode.
         tc->setMiscReg(MISCREG_CR0, cr0);
-
-        Efer efer = 0;
-        efer.sce = 1; // Enable system call extensions.
-        efer.lme = 1; // Enable long mode.
-        efer.lma = 1; // Activate long mode.
-        efer.nxe = 1; // Enable nx support.
-        efer.svme = 0; // Disable svm support for now. It isn't implemented.
-        efer.ffxsr = 1; // Turn on fast fxsave and fxrstor.
-        tc->setMiscReg(MISCREG_EFER, efer);
     }
 }
 
@@ -340,6 +340,15 @@ I386LiveProcess::startup()
         // Set the LDT selector to 0 to deactivate it.
         tc->setMiscRegNoEffect(MISCREG_TSL, 0);
 
+        Efer efer = 0;
+        efer.sce = 1; // Enable system call extensions.
+        efer.lme = 1; // Enable long mode.
+        efer.lma = 0; // Deactivate long mode.
+        efer.nxe = 1; // Enable nx support.
+        efer.svme = 0; // Disable svm support for now. It isn't implemented.
+        efer.ffxsr = 1; // Turn on fast fxsave and fxrstor.
+        tc->setMiscReg(MISCREG_EFER, efer);
+
         //Set up the registers that describe the operating mode.
         CR0 cr0 = 0;
         cr0.pg = 1; // Turn on paging.
@@ -356,15 +365,6 @@ I386LiveProcess::startup()
                     // setting it to one.
         cr0.pe = 1; // We're definitely in protected mode.
         tc->setMiscReg(MISCREG_CR0, cr0);
-
-        Efer efer = 0;
-        efer.sce = 1; // Enable system call extensions.
-        efer.lme = 1; // Enable long mode.
-        efer.lma = 0; // Deactivate long mode.
-        efer.nxe = 1; // Enable nx support.
-        efer.svme = 0; // Disable svm support for now. It isn't implemented.
-        efer.ffxsr = 1; // Turn on fast fxsave and fxrstor.
-        tc->setMiscReg(MISCREG_EFER, efer);
     }
 }
 
diff --git a/src/arch/x86/tlb.cc b/src/arch/x86/tlb.cc
index f8b5c3392..1478c3e66 100644
--- a/src/arch/x86/tlb.cc
+++ b/src/arch/x86/tlb.cc
@@ -185,392 +185,394 @@ TLB::demapPage(Addr va, uint64_t asn)
     }
 }
 
+Fault
+TLB::translateInt(RequestPtr req, ThreadContext *tc)
+{
+    DPRINTF(TLB, "Addresses references internal memory.\n");
+    Addr vaddr = req->getVaddr();
+    Addr prefix = (vaddr >> 3) & IntAddrPrefixMask;
+    if (prefix == IntAddrPrefixCPUID) {
+        panic("CPUID memory space not yet implemented!\n");
+    } else if (prefix == IntAddrPrefixMSR) {
+        vaddr = vaddr >> 3;
+        req->setMmapedIpr(true);
+        Addr regNum = 0;
+        switch (vaddr & ~IntAddrPrefixMask) {
+          case 0x10:
+            regNum = MISCREG_TSC;
+            break;
+          case 0x1B:
+            regNum = MISCREG_APIC_BASE;
+            break;
+          case 0xFE:
+            regNum = MISCREG_MTRRCAP;
+            break;
+          case 0x174:
+            regNum = MISCREG_SYSENTER_CS;
+            break;
+          case 0x175:
+            regNum = MISCREG_SYSENTER_ESP;
+            break;
+          case 0x176:
+            regNum = MISCREG_SYSENTER_EIP;
+            break;
+          case 0x179:
+            regNum = MISCREG_MCG_CAP;
+            break;
+          case 0x17A:
+            regNum = MISCREG_MCG_STATUS;
+            break;
+          case 0x17B:
+            regNum = MISCREG_MCG_CTL;
+            break;
+          case 0x1D9:
+            regNum = MISCREG_DEBUG_CTL_MSR;
+            break;
+          case 0x1DB:
+            regNum = MISCREG_LAST_BRANCH_FROM_IP;
+            break;
+          case 0x1DC:
+            regNum = MISCREG_LAST_BRANCH_TO_IP;
+            break;
+          case 0x1DD:
+            regNum = MISCREG_LAST_EXCEPTION_FROM_IP;
+            break;
+          case 0x1DE:
+            regNum = MISCREG_LAST_EXCEPTION_TO_IP;
+            break;
+          case 0x200:
+            regNum = MISCREG_MTRR_PHYS_BASE_0;
+            break;
+          case 0x201:
+            regNum = MISCREG_MTRR_PHYS_MASK_0;
+            break;
+          case 0x202:
+            regNum = MISCREG_MTRR_PHYS_BASE_1;
+            break;
+          case 0x203:
+            regNum = MISCREG_MTRR_PHYS_MASK_1;
+            break;
+          case 0x204:
+            regNum = MISCREG_MTRR_PHYS_BASE_2;
+            break;
+          case 0x205:
+            regNum = MISCREG_MTRR_PHYS_MASK_2;
+            break;
+          case 0x206:
+            regNum = MISCREG_MTRR_PHYS_BASE_3;
+            break;
+          case 0x207:
+            regNum = MISCREG_MTRR_PHYS_MASK_3;
+            break;
+          case 0x208:
+            regNum = MISCREG_MTRR_PHYS_BASE_4;
+            break;
+          case 0x209:
+            regNum = MISCREG_MTRR_PHYS_MASK_4;
+            break;
+          case 0x20A:
+            regNum = MISCREG_MTRR_PHYS_BASE_5;
+            break;
+          case 0x20B:
+            regNum = MISCREG_MTRR_PHYS_MASK_5;
+            break;
+          case 0x20C:
+            regNum = MISCREG_MTRR_PHYS_BASE_6;
+            break;
+          case 0x20D:
+            regNum = MISCREG_MTRR_PHYS_MASK_6;
+            break;
+          case 0x20E:
+            regNum = MISCREG_MTRR_PHYS_BASE_7;
+            break;
+          case 0x20F:
+            regNum = MISCREG_MTRR_PHYS_MASK_7;
+            break;
+          case 0x250:
+            regNum = MISCREG_MTRR_FIX_64K_00000;
+            break;
+          case 0x258:
+            regNum = MISCREG_MTRR_FIX_16K_80000;
+            break;
+          case 0x259:
+            regNum = MISCREG_MTRR_FIX_16K_A0000;
+            break;
+          case 0x268:
+            regNum = MISCREG_MTRR_FIX_4K_C0000;
+            break;
+          case 0x269:
+            regNum = MISCREG_MTRR_FIX_4K_C8000;
+            break;
+          case 0x26A:
+            regNum = MISCREG_MTRR_FIX_4K_D0000;
+            break;
+          case 0x26B:
+            regNum = MISCREG_MTRR_FIX_4K_D8000;
+            break;
+          case 0x26C:
+            regNum = MISCREG_MTRR_FIX_4K_E0000;
+            break;
+          case 0x26D:
+            regNum = MISCREG_MTRR_FIX_4K_E8000;
+            break;
+          case 0x26E:
+            regNum = MISCREG_MTRR_FIX_4K_F0000;
+            break;
+          case 0x26F:
+            regNum = MISCREG_MTRR_FIX_4K_F8000;
+            break;
+          case 0x277:
+            regNum = MISCREG_PAT;
+            break;
+          case 0x2FF:
+            regNum = MISCREG_DEF_TYPE;
+            break;
+          case 0x400:
+            regNum = MISCREG_MC0_CTL;
+            break;
+          case 0x404:
+            regNum = MISCREG_MC1_CTL;
+            break;
+          case 0x408:
+            regNum = MISCREG_MC2_CTL;
+            break;
+          case 0x40C:
+            regNum = MISCREG_MC3_CTL;
+            break;
+          case 0x410:
+            regNum = MISCREG_MC4_CTL;
+            break;
+          case 0x414:
+            regNum = MISCREG_MC5_CTL;
+            break;
+          case 0x418:
+            regNum = MISCREG_MC6_CTL;
+            break;
+          case 0x41C:
+            regNum = MISCREG_MC7_CTL;
+            break;
+          case 0x401:
+            regNum = MISCREG_MC0_STATUS;
+            break;
+          case 0x405:
+            regNum = MISCREG_MC1_STATUS;
+            break;
+          case 0x409:
+            regNum = MISCREG_MC2_STATUS;
+            break;
+          case 0x40D:
+            regNum = MISCREG_MC3_STATUS;
+            break;
+          case 0x411:
+            regNum = MISCREG_MC4_STATUS;
+            break;
+          case 0x415:
+            regNum = MISCREG_MC5_STATUS;
+            break;
+          case 0x419:
+            regNum = MISCREG_MC6_STATUS;
+            break;
+          case 0x41D:
+            regNum = MISCREG_MC7_STATUS;
+            break;
+          case 0x402:
+            regNum = MISCREG_MC0_ADDR;
+            break;
+          case 0x406:
+            regNum = MISCREG_MC1_ADDR;
+            break;
+          case 0x40A:
+            regNum = MISCREG_MC2_ADDR;
+            break;
+          case 0x40E:
+            regNum = MISCREG_MC3_ADDR;
+            break;
+          case 0x412:
+            regNum = MISCREG_MC4_ADDR;
+            break;
+          case 0x416:
+            regNum = MISCREG_MC5_ADDR;
+            break;
+          case 0x41A:
+            regNum = MISCREG_MC6_ADDR;
+            break;
+          case 0x41E:
+            regNum = MISCREG_MC7_ADDR;
+            break;
+          case 0x403:
+            regNum = MISCREG_MC0_MISC;
+            break;
+          case 0x407:
+            regNum = MISCREG_MC1_MISC;
+            break;
+          case 0x40B:
+            regNum = MISCREG_MC2_MISC;
+            break;
+          case 0x40F:
+            regNum = MISCREG_MC3_MISC;
+            break;
+          case 0x413:
+            regNum = MISCREG_MC4_MISC;
+            break;
+          case 0x417:
+            regNum = MISCREG_MC5_MISC;
+            break;
+          case 0x41B:
+            regNum = MISCREG_MC6_MISC;
+            break;
+          case 0x41F:
+            regNum = MISCREG_MC7_MISC;
+            break;
+          case 0xC0000080:
+            regNum = MISCREG_EFER;
+            break;
+          case 0xC0000081:
+            regNum = MISCREG_STAR;
+            break;
+          case 0xC0000082:
+            regNum = MISCREG_LSTAR;
+            break;
+          case 0xC0000083:
+            regNum = MISCREG_CSTAR;
+            break;
+          case 0xC0000084:
+            regNum = MISCREG_SF_MASK;
+            break;
+          case 0xC0000100:
+            regNum = MISCREG_FS_BASE;
+            break;
+          case 0xC0000101:
+            regNum = MISCREG_GS_BASE;
+            break;
+          case 0xC0000102:
+            regNum = MISCREG_KERNEL_GS_BASE;
+            break;
+          case 0xC0000103:
+            regNum = MISCREG_TSC_AUX;
+            break;
+          case 0xC0010000:
+            regNum = MISCREG_PERF_EVT_SEL0;
+            break;
+          case 0xC0010001:
+            regNum = MISCREG_PERF_EVT_SEL1;
+            break;
+          case 0xC0010002:
+            regNum = MISCREG_PERF_EVT_SEL2;
+            break;
+          case 0xC0010003:
+            regNum = MISCREG_PERF_EVT_SEL3;
+            break;
+          case 0xC0010004:
+            regNum = MISCREG_PERF_EVT_CTR0;
+            break;
+          case 0xC0010005:
+            regNum = MISCREG_PERF_EVT_CTR1;
+            break;
+          case 0xC0010006:
+            regNum = MISCREG_PERF_EVT_CTR2;
+            break;
+          case 0xC0010007:
+            regNum = MISCREG_PERF_EVT_CTR3;
+            break;
+          case 0xC0010010:
+            regNum = MISCREG_SYSCFG;
+            break;
+          case 0xC0010016:
+            regNum = MISCREG_IORR_BASE0;
+            break;
+          case 0xC0010017:
+            regNum = MISCREG_IORR_BASE1;
+            break;
+          case 0xC0010018:
+            regNum = MISCREG_IORR_MASK0;
+            break;
+          case 0xC0010019:
+            regNum = MISCREG_IORR_MASK1;
+            break;
+          case 0xC001001A:
+            regNum = MISCREG_TOP_MEM;
+            break;
+          case 0xC001001D:
+            regNum = MISCREG_TOP_MEM2;
+            break;
+          case 0xC0010114:
+            regNum = MISCREG_VM_CR;
+            break;
+          case 0xC0010115:
+            regNum = MISCREG_IGNNE;
+            break;
+          case 0xC0010116:
+            regNum = MISCREG_SMM_CTL;
+            break;
+          case 0xC0010117:
+            regNum = MISCREG_VM_HSAVE_PA;
+            break;
+          default:
+            return new GeneralProtection(0);
+        }
+        //The index is multiplied by the size of a MiscReg so that
+        //any memory dependence calculations will not see these as
+        //overlapping.
+        req->setPaddr(regNum * sizeof(MiscReg));
+        return NoFault;
+    } else if (prefix == IntAddrPrefixIO) {
+        // TODO If CPL > IOPL or in virtual mode, check the I/O permission
+        // bitmap in the TSS.
+
+        Addr IOPort = vaddr & ~IntAddrPrefixMask;
+        // Make sure the address fits in the expected 16 bit IO address
+        // space.
+        assert(!(IOPort & ~0xFFFF));
+        if (IOPort == 0xCF8 && req->getSize() == 4) {
+            req->setMmapedIpr(true);
+            req->setPaddr(MISCREG_PCI_CONFIG_ADDRESS * sizeof(MiscReg));
+        } else if ((IOPort & ~mask(2)) == 0xCFC) {
+            Addr configAddress =
+                tc->readMiscRegNoEffect(MISCREG_PCI_CONFIG_ADDRESS);
+            if (bits(configAddress, 31, 31)) {
+                req->setPaddr(PhysAddrPrefixPciConfig |
+                        mbits(configAddress, 30, 2) |
+                        (IOPort & mask(2)));
+            }
+        } else {
+            req->setPaddr(PhysAddrPrefixIO | IOPort);
+        }
+        return NoFault;
+    } else {
+        panic("Access to unrecognized internal address space %#x.\n",
+                prefix);
+    }
+}
+
 Fault
 TLB::translate(RequestPtr req, ThreadContext *tc, Translation *translation,
         Mode mode, bool &delayedResponse, bool timing)
 {
+    uint32_t flags = req->getFlags();
+    int seg = flags & SegmentFlagMask;
+    bool storeCheck = flags & (StoreCheck << FlagShift);
+
+    // If this is true, we're dealing with a request to a non-memory address
+    // space.
+    if (seg == SEGMENT_REG_MS) {
+        return translateInt(req, tc);
+    }
+
     delayedResponse = false;
     Addr vaddr = req->getVaddr();
     DPRINTF(TLB, "Translating vaddr %#x.\n", vaddr);
-    uint32_t flags = req->getFlags();
-    bool storeCheck = flags & (StoreCheck << FlagShift);
 
-    int seg = flags & SegmentFlagMask;
-
-    // If this is true, we're dealing with a request to read an internal
-    // value.
-    if (seg == SEGMENT_REG_MS) {
-        DPRINTF(TLB, "Addresses references internal memory.\n");
-        Addr prefix = (vaddr >> 3) & IntAddrPrefixMask;
-        if (prefix == IntAddrPrefixCPUID) {
-            panic("CPUID memory space not yet implemented!\n");
-        } else if (prefix == IntAddrPrefixMSR) {
-            vaddr = vaddr >> 3;
-            req->setMmapedIpr(true);
-            Addr regNum = 0;
-            switch (vaddr & ~IntAddrPrefixMask) {
-              case 0x10:
-                regNum = MISCREG_TSC;
-                break;
-              case 0x1B:
-                regNum = MISCREG_APIC_BASE;
-                break;
-              case 0xFE:
-                regNum = MISCREG_MTRRCAP;
-                break;
-              case 0x174:
-                regNum = MISCREG_SYSENTER_CS;
-                break;
-              case 0x175:
-                regNum = MISCREG_SYSENTER_ESP;
-                break;
-              case 0x176:
-                regNum = MISCREG_SYSENTER_EIP;
-                break;
-              case 0x179:
-                regNum = MISCREG_MCG_CAP;
-                break;
-              case 0x17A:
-                regNum = MISCREG_MCG_STATUS;
-                break;
-              case 0x17B:
-                regNum = MISCREG_MCG_CTL;
-                break;
-              case 0x1D9:
-                regNum = MISCREG_DEBUG_CTL_MSR;
-                break;
-              case 0x1DB:
-                regNum = MISCREG_LAST_BRANCH_FROM_IP;
-                break;
-              case 0x1DC:
-                regNum = MISCREG_LAST_BRANCH_TO_IP;
-                break;
-              case 0x1DD:
-                regNum = MISCREG_LAST_EXCEPTION_FROM_IP;
-                break;
-              case 0x1DE:
-                regNum = MISCREG_LAST_EXCEPTION_TO_IP;
-                break;
-              case 0x200:
-                regNum = MISCREG_MTRR_PHYS_BASE_0;
-                break;
-              case 0x201:
-                regNum = MISCREG_MTRR_PHYS_MASK_0;
-                break;
-              case 0x202:
-                regNum = MISCREG_MTRR_PHYS_BASE_1;
-                break;
-              case 0x203:
-                regNum = MISCREG_MTRR_PHYS_MASK_1;
-                break;
-              case 0x204:
-                regNum = MISCREG_MTRR_PHYS_BASE_2;
-                break;
-              case 0x205:
-                regNum = MISCREG_MTRR_PHYS_MASK_2;
-                break;
-              case 0x206:
-                regNum = MISCREG_MTRR_PHYS_BASE_3;
-                break;
-              case 0x207:
-                regNum = MISCREG_MTRR_PHYS_MASK_3;
-                break;
-              case 0x208:
-                regNum = MISCREG_MTRR_PHYS_BASE_4;
-                break;
-              case 0x209:
-                regNum = MISCREG_MTRR_PHYS_MASK_4;
-                break;
-              case 0x20A:
-                regNum = MISCREG_MTRR_PHYS_BASE_5;
-                break;
-              case 0x20B:
-                regNum = MISCREG_MTRR_PHYS_MASK_5;
-                break;
-              case 0x20C:
-                regNum = MISCREG_MTRR_PHYS_BASE_6;
-                break;
-              case 0x20D:
-                regNum = MISCREG_MTRR_PHYS_MASK_6;
-                break;
-              case 0x20E:
-                regNum = MISCREG_MTRR_PHYS_BASE_7;
-                break;
-              case 0x20F:
-                regNum = MISCREG_MTRR_PHYS_MASK_7;
-                break;
-              case 0x250:
-                regNum = MISCREG_MTRR_FIX_64K_00000;
-                break;
-              case 0x258:
-                regNum = MISCREG_MTRR_FIX_16K_80000;
-                break;
-              case 0x259:
-                regNum = MISCREG_MTRR_FIX_16K_A0000;
-                break;
-              case 0x268:
-                regNum = MISCREG_MTRR_FIX_4K_C0000;
-                break;
-              case 0x269:
-                regNum = MISCREG_MTRR_FIX_4K_C8000;
-                break;
-              case 0x26A:
-                regNum = MISCREG_MTRR_FIX_4K_D0000;
-                break;
-              case 0x26B:
-                regNum = MISCREG_MTRR_FIX_4K_D8000;
-                break;
-              case 0x26C:
-                regNum = MISCREG_MTRR_FIX_4K_E0000;
-                break;
-              case 0x26D:
-                regNum = MISCREG_MTRR_FIX_4K_E8000;
-                break;
-              case 0x26E:
-                regNum = MISCREG_MTRR_FIX_4K_F0000;
-                break;
-              case 0x26F:
-                regNum = MISCREG_MTRR_FIX_4K_F8000;
-                break;
-              case 0x277:
-                regNum = MISCREG_PAT;
-                break;
-              case 0x2FF:
-                regNum = MISCREG_DEF_TYPE;
-                break;
-              case 0x400:
-                regNum = MISCREG_MC0_CTL;
-                break;
-              case 0x404:
-                regNum = MISCREG_MC1_CTL;
-                break;
-              case 0x408:
-                regNum = MISCREG_MC2_CTL;
-                break;
-              case 0x40C:
-                regNum = MISCREG_MC3_CTL;
-                break;
-              case 0x410:
-                regNum = MISCREG_MC4_CTL;
-                break;
-              case 0x414:
-                regNum = MISCREG_MC5_CTL;
-                break;
-              case 0x418:
-                regNum = MISCREG_MC6_CTL;
-                break;
-              case 0x41C:
-                regNum = MISCREG_MC7_CTL;
-                break;
-              case 0x401:
-                regNum = MISCREG_MC0_STATUS;
-                break;
-              case 0x405:
-                regNum = MISCREG_MC1_STATUS;
-                break;
-              case 0x409:
-                regNum = MISCREG_MC2_STATUS;
-                break;
-              case 0x40D:
-                regNum = MISCREG_MC3_STATUS;
-                break;
-              case 0x411:
-                regNum = MISCREG_MC4_STATUS;
-                break;
-              case 0x415:
-                regNum = MISCREG_MC5_STATUS;
-                break;
-              case 0x419:
-                regNum = MISCREG_MC6_STATUS;
-                break;
-              case 0x41D:
-                regNum = MISCREG_MC7_STATUS;
-                break;
-              case 0x402:
-                regNum = MISCREG_MC0_ADDR;
-                break;
-              case 0x406:
-                regNum = MISCREG_MC1_ADDR;
-                break;
-              case 0x40A:
-                regNum = MISCREG_MC2_ADDR;
-                break;
-              case 0x40E:
-                regNum = MISCREG_MC3_ADDR;
-                break;
-              case 0x412:
-                regNum = MISCREG_MC4_ADDR;
-                break;
-              case 0x416:
-                regNum = MISCREG_MC5_ADDR;
-                break;
-              case 0x41A:
-                regNum = MISCREG_MC6_ADDR;
-                break;
-              case 0x41E:
-                regNum = MISCREG_MC7_ADDR;
-                break;
-              case 0x403:
-                regNum = MISCREG_MC0_MISC;
-                break;
-              case 0x407:
-                regNum = MISCREG_MC1_MISC;
-                break;
-              case 0x40B:
-                regNum = MISCREG_MC2_MISC;
-                break;
-              case 0x40F:
-                regNum = MISCREG_MC3_MISC;
-                break;
-              case 0x413:
-                regNum = MISCREG_MC4_MISC;
-                break;
-              case 0x417:
-                regNum = MISCREG_MC5_MISC;
-                break;
-              case 0x41B:
-                regNum = MISCREG_MC6_MISC;
-                break;
-              case 0x41F:
-                regNum = MISCREG_MC7_MISC;
-                break;
-              case 0xC0000080:
-                regNum = MISCREG_EFER;
-                break;
-              case 0xC0000081:
-                regNum = MISCREG_STAR;
-                break;
-              case 0xC0000082:
-                regNum = MISCREG_LSTAR;
-                break;
-              case 0xC0000083:
-                regNum = MISCREG_CSTAR;
-                break;
-              case 0xC0000084:
-                regNum = MISCREG_SF_MASK;
-                break;
-              case 0xC0000100:
-                regNum = MISCREG_FS_BASE;
-                break;
-              case 0xC0000101:
-                regNum = MISCREG_GS_BASE;
-                break;
-              case 0xC0000102:
-                regNum = MISCREG_KERNEL_GS_BASE;
-                break;
-              case 0xC0000103:
-                regNum = MISCREG_TSC_AUX;
-                break;
-              case 0xC0010000:
-                regNum = MISCREG_PERF_EVT_SEL0;
-                break;
-              case 0xC0010001:
-                regNum = MISCREG_PERF_EVT_SEL1;
-                break;
-              case 0xC0010002:
-                regNum = MISCREG_PERF_EVT_SEL2;
-                break;
-              case 0xC0010003:
-                regNum = MISCREG_PERF_EVT_SEL3;
-                break;
-              case 0xC0010004:
-                regNum = MISCREG_PERF_EVT_CTR0;
-                break;
-              case 0xC0010005:
-                regNum = MISCREG_PERF_EVT_CTR1;
-                break;
-              case 0xC0010006:
-                regNum = MISCREG_PERF_EVT_CTR2;
-                break;
-              case 0xC0010007:
-                regNum = MISCREG_PERF_EVT_CTR3;
-                break;
-              case 0xC0010010:
-                regNum = MISCREG_SYSCFG;
-                break;
-              case 0xC0010016:
-                regNum = MISCREG_IORR_BASE0;
-                break;
-              case 0xC0010017:
-                regNum = MISCREG_IORR_BASE1;
-                break;
-              case 0xC0010018:
-                regNum = MISCREG_IORR_MASK0;
-                break;
-              case 0xC0010019:
-                regNum = MISCREG_IORR_MASK1;
-                break;
-              case 0xC001001A:
-                regNum = MISCREG_TOP_MEM;
-                break;
-              case 0xC001001D:
-                regNum = MISCREG_TOP_MEM2;
-                break;
-              case 0xC0010114:
-                regNum = MISCREG_VM_CR;
-                break;
-              case 0xC0010115:
-                regNum = MISCREG_IGNNE;
-                break;
-              case 0xC0010116:
-                regNum = MISCREG_SMM_CTL;
-                break;
-              case 0xC0010117:
-                regNum = MISCREG_VM_HSAVE_PA;
-                break;
-              default:
-                return new GeneralProtection(0);
-            }
-            //The index is multiplied by the size of a MiscReg so that
-            //any memory dependence calculations will not see these as
-            //overlapping.
-            req->setPaddr(regNum * sizeof(MiscReg));
-            return NoFault;
-        } else if (prefix == IntAddrPrefixIO) {
-            // TODO If CPL > IOPL or in virtual mode, check the I/O permission
-            // bitmap in the TSS.
-
-            Addr IOPort = vaddr & ~IntAddrPrefixMask;
-            // Make sure the address fits in the expected 16 bit IO address
-            // space.
-            assert(!(IOPort & ~0xFFFF));
-            if (IOPort == 0xCF8 && req->getSize() == 4) {
-                req->setMmapedIpr(true);
-                req->setPaddr(MISCREG_PCI_CONFIG_ADDRESS * sizeof(MiscReg));
-            } else if ((IOPort & ~mask(2)) == 0xCFC) {
-                Addr configAddress =
-                    tc->readMiscRegNoEffect(MISCREG_PCI_CONFIG_ADDRESS);
-                if (bits(configAddress, 31, 31)) {
-                    req->setPaddr(PhysAddrPrefixPciConfig |
-                            mbits(configAddress, 30, 2) |
-                            (IOPort & mask(2)));
-                }
-            } else {
-                req->setPaddr(PhysAddrPrefixIO | IOPort);
-            }
-            return NoFault;
-        } else {
-            panic("Access to unrecognized internal address space %#x.\n",
-                    prefix);
-        }
-    }
-
-    // Get cr0. This will tell us how to do translation. We'll assume it was
-    // verified to be correct and consistent when set.
-    CR0 cr0 = tc->readMiscRegNoEffect(MISCREG_CR0);
+    HandyM5Reg m5Reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
 
     // If protected mode has been enabled...
-    if (cr0.pe) {
+    if (m5Reg.prot) {
         DPRINTF(TLB, "In protected mode.\n");
-        Efer efer = tc->readMiscRegNoEffect(MISCREG_EFER);
-        SegAttr csAttr = tc->readMiscRegNoEffect(MISCREG_CS_ATTR);
         // If we're not in 64-bit mode, do protection/limit checks
-        if (!efer.lma || !csAttr.longMode) {
+        if (m5Reg.mode != LongMode) {
             DPRINTF(TLB, "Not in long mode. Checking segment protection.\n");
             // Check for a NULL segment selector.
             if (!(seg == SEGMENT_REG_TSG || seg == SYS_SEGMENT_REG_IDTR ||
-                        seg == SEGMENT_REG_HS || seg == SEGMENT_REG_LS ||
-                        seg == SEGMENT_REG_MS)
+                        seg == SEGMENT_REG_HS || seg == SEGMENT_REG_LS)
                     && !tc->readMiscRegNoEffect(MISCREG_SEG_SEL(seg)))
                 return new GeneralProtection(0);
             bool expandDown = false;
@@ -589,6 +591,7 @@ TLB::translate(RequestPtr req, ThreadContext *tc, Translation *translation,
             // address size is 64 bits, overridable to 32.
             int size = 32;
             bool sizeOverride = (flags & (AddrSizeFlagBit << FlagShift));
+            SegAttr csAttr = tc->readMiscRegNoEffect(MISCREG_CS_ATTR);
             if ((csAttr.defaultSize && sizeOverride) ||
                     (!csAttr.defaultSize && !sizeOverride))
                 size = 16;
@@ -605,7 +608,7 @@ TLB::translate(RequestPtr req, ThreadContext *tc, Translation *translation,
             }
         }
         // If paging is enabled, do the translation.
-        if (cr0.pg) {
+        if (m5Reg.paging) {
             DPRINTF(TLB, "Paging enabled.\n");
             // The vaddr already has the segment base applied.
             TlbEntry *entry = lookup(vaddr);
@@ -643,7 +646,7 @@ TLB::translate(RequestPtr req, ThreadContext *tc, Translation *translation,
 #endif
             }
             // Do paging protection checks.
-            bool inUser = (csAttr.dpl == 3 &&
+            bool inUser = (m5Reg.cpl == 3 &&
                     !(flags & (CPL0FlagBit << FlagShift)));
             if ((inUser && !entry->user) ||
                 (mode == Write && !entry->writable)) {
diff --git a/src/arch/x86/tlb.hh b/src/arch/x86/tlb.hh
index f55c26435..dca95eaaf 100644
--- a/src/arch/x86/tlb.hh
+++ b/src/arch/x86/tlb.hh
@@ -124,6 +124,8 @@ namespace X86ISA
         EntryList freeList;
         EntryList entryList;
 
+        Fault translateInt(RequestPtr req, ThreadContext *tc);
+
         Fault translate(RequestPtr req, ThreadContext *tc,
                 Translation *translation, Mode mode,
                 bool &delayedResponse, bool timing);
diff --git a/src/sim/SConscript b/src/sim/SConscript
index 750007947..c13ea9909 100644
--- a/src/sim/SConscript
+++ b/src/sim/SConscript
@@ -41,7 +41,7 @@ Source('debug.cc')
 Source('eventq.cc')
 Source('faults.cc')
 Source('init.cc')
-BinSource('main.cc')
+Source('main.cc', bin_only=True)
 Source('pseudo_inst.cc')
 Source('root.cc')
 Source('serialize.cc')