Add board option to au test harness so that this works for others without a default board.

lib/cros_build_lib.py

Index: lib/cros_build_lib.py
diff --git a/lib/cros_build_lib.py b/lib/cros_build_lib.py
index 71c908648f764575433251a16b45ff181df03f2e..47c8f96ae659b6b31394da97f78107f0e10ffa9d 100644
--- a/lib/cros_build_lib.py
+++ b/lib/cros_build_lib.py
@@ -136,3 +136,36 @@ def Info(message):
   """
   print >> sys.stderr, (
       Color(_STDOUT_IS_TTY).Color(Color.BLUE, '\nINFO: ' + message))
+
+
+def FindRepoDir():
+  """Returns the nearest higher-level repo dir from the cwd."""
+  cwd = os.getcwd()
+  while cwd != '/':
+    repo_dir = os.path.join(cwd, '.repo')
+    if os.path.isdir(repo_dir):
+      return repo_dir
+    cwd = os.path.dirname(cwd)
+  return None
+
+
+def ReinterpretPathForChroot(path):
+  """Returns reinterpreted path from outside the chroot for use inside.
+
+  Keyword arguments:
+    path: The path to reinterpret.  Must be in src tree.
+  """
+  root_path = os.path.join(FindRepoDir(), '..')
+
+  path_abs_path = os.path.abspath(path)
+  root_abs_path = os.path.abspath(root_path)
+
+  # Strip the repository root from the path and strip first /.
+  relative_path = path_abs_path.replace(root_abs_path, '')[1:]
+
+  if relative_path == path_abs_path:
+    raise Exception('Error: path is outside your src tree, cannot reinterpret.')
+
+  new_path = os.path.join('/home', os.getenv('USER'), 'trunk', relative_path)
+  return new_path
+