diff --git a/configs/common/SysPaths.py b/configs/common/SysPaths.py
--- a/configs/common/SysPaths.py
+++ b/configs/common/SysPaths.py
@@ -26,46 +26,25 @@
 #
 # Authors: Ali Saidi
 
-import os, sys
-from os.path import isdir, join as joinpath
-from os import environ as env
+import os
 
+from path import Path, SubPath
+
+args = []
+try:
+    args.append(os.environ['M5_PATH'])
+except KeyError:
+    args = [ '/dist/m5/system', '/n/poolfs/z/dist/m5/system' ]
 config_path = os.path.dirname(os.path.abspath(__file__))
 config_root = os.path.dirname(config_path)
+args.append(config_root)
 
-def disk(file):
-    system()
-    return joinpath(disk.dir, file)
+system = Path(args)
 
-def binary(file):
-    system()
-    return joinpath(binary.dir, file)
+# nesting SubPath in Path so, the subdir only applies to system and
+# does not apply to any new path added
+disk = Path(SubPath(system, 'disks'))
+binary = Path(SubPath(system, 'binaries'))
+script = Path(SubPath(system, 'boot'))
 
-def script(file):
-    system()
-    return joinpath(script.dir, file)
-
-def system():
-    if not system.dir:
-        try:
-                path = env['M5_PATH'].split(':')
-        except KeyError:
-                path = [ '/dist/m5/system', '/n/poolfs/z/dist/m5/system' ]
-
-        for system.dir in path:
-            if os.path.isdir(system.dir):
-                break
-        else:
-            raise ImportError, "Can't find a path to system files."
-
-    if not binary.dir:
-        binary.dir = joinpath(system.dir, 'binaries')
-    if not disk.dir:
-        disk.dir = joinpath(system.dir, 'disks')
-    if not script.dir:
-        script.dir = joinpath(config_root, 'boot')
-
-system.dir = None
-binary.dir = None
-disk.dir = None
-script.dir = None
+__all__ = [ 'system', 'disk', 'binary', 'script' ]
diff --git a/configs/common/path.py b/configs/common/path.py
--- /dev/null
+++ b/configs/common/path.py
@@ -0,0 +1,86 @@
+import os, sys
+from os.path import dirname, isdir, isfile, join as joinpath
+from os import environ as env
+
+class Base(object):
+    def find(self, file, test=isfile):
+        for dir in self:
+            f = joinpath(dir, file)
+            if test(f):
+                return f
+        else:
+            return None
+
+    def __call__(self, file, exception=AttributeError):
+        result = self.find(file)
+        if result is None and exception is not None:
+            raise exception, "Could not find file %s in path %s" % (file, self)
+
+        return result
+
+class Path(Base):
+    def __init__(self, *args):
+        self.path = []
+        self.extend(args)
+
+    def subpath(self, subdir):
+        return SubPath(self, subdir)
+
+    def clear(self):
+        self.path.clear()
+
+    def append(self, path):
+        if isinstance(path, Base):
+            self.path.append(path)
+        elif isinstance(path, str):
+            self.path.extend(path.split(':'))
+        elif isinstance(path, (list, tuple)):
+            self.extend(path)
+        else:
+            raise AttributeError, "Invalid argument to path '%s'" % path
+
+    def extend(self, items):
+        for item in items:
+            self.append(item)
+
+    def __iter__(self):
+        for item in self.path:
+            if isinstance(item, Base):
+                for i in item:
+                    yield i
+            else:
+                yield item
+
+    def __len__(self):
+        count = 0
+        for item in self.path:
+            if isinstance(item, Path):
+                count += len(item)
+            else:
+                count += 1
+
+    def __str__(self):
+        return ':'.join(list(self))
+
+    def __repr__(self):
+        return 'Path(%s)' % self.path
+
+class SubPath(Base):
+    def __init__(self, parent, subdir):
+        self.parent = parent
+        self.subdir = subdir
+
+    def __iter__(self):
+        for item in self.parent:
+            yield joinpath(item, self.subdir)
+
+    def __len__(self):
+        return len(self.parent)
+
+    def __str__(self):
+        return ':'.join(list(self))
+
+    def __repr__(self):
+        return "SubPath(%s, '%s')" % (`self.parent`, self.subdir)
+
+__all__ = [ 'Base', 'Path', 'SubPath']