diff --git a/util/style/repo.py b/util/style/repo.py
new file mode 100644
index 000000000..1943e48b6
--- /dev/null
+++ b/util/style/repo.py
@@ -0,0 +1,277 @@
+#!/usr/bin/env python
+#
+# Copyright (c) 2016 ARM Limited
+# All rights reserved
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Andreas Sandberg
+
+from abc import *
+import os
+import subprocess
+
+from region import *
+from style import modified_regions
+
+class AbstractRepo(object):
+    __metaclass__ = ABCMeta
+
+    def file_path(self, fname):
+        """Get the absolute path to a file relative within the repository. The
+        input file name must be a valid path within the repository.
+
+        """
+        return os.path.join(self.repo_base(), fname)
+
+    def in_repo(self, fname):
+        """Check if a path points to something within the repository base. Not
+        that this does not check for the presence of the object in the
+        file system as it could exist in the index without being in
+        the file system.
+
+        """
+        fname = os.path.abspath(fname)
+        repo_path = os.path.abspath(self.repo_base())
+
+        return os.path.commonprefix([repo_path, fname]) == repo_path
+
+    def repo_path(self, fname):
+        """Get the path of a file relative to the repository base. The input
+        file name is assumed to be an absolute path or a path relative
+        to the current working directory.
+
+        """
+        return os.path.relpath(fname, self.repo_base())
+
+    def get_file(self, name):
+        """Get the contents of a file in the file system using a path relative
+        to the repository root.
+
+        """
+        with open(self.file_path(name), "r") as f:
+            return f.read()
+
+    @abstractmethod
+    def repo_base(self):
+        """Get the path to the base of the repository"""
+        pass
+
+    @abstractmethod
+    def staged_files(self):
+        """Get a tuple describing the files that have been staged for a
+        commit: (list of new, list of modified)
+
+        """
+        pass
+
+    @abstractmethod
+    def staged_regions(self, fname, context=0):
+        """Get modified regions that will be committed by the next commit
+        command
+
+        """
+        pass
+
+    @abstractmethod
+    def modified_regions(self, fname, context=0):
+        """Get modified regions that have been staged for commit or are
+        present in the file system.
+
+        """
+        pass
+
+class GitRepo(AbstractRepo):
+    def __init__(self):
+        self.git = "git"
+        self._head_revision = None
+        self._repo_base = None
+
+    def repo_base(self):
+        if self._repo_base is None:
+            self._repo_base = subprocess.check_output(
+                [ self.git, "rev-parse", "--show-toplevel" ]).rstrip("\n")
+
+        return self._repo_base
+
+    def staged_files(self):
+        added = []
+        modified = []
+        for action, fname in self.status(filter="MA", cached=True):
+            if action == "M":
+                modified.append(fname)
+            elif action == "A":
+                added.append(fname)
+
+        return added, modified
+
+    def staged_regions(self, fname, context=0):
+        if self.file_status(fname, cached=True) in ("", "A", ):
+            return all_regions
+
+        old = self.file_from_head(self.repo_path(fname)).split("\n")
+        new = self.file_from_index(self.repo_path(fname)).split("\n")
+
+        return modified_regions(old, new, context=context)
+
+    def modified_regions(self, fname, context=0):
+        if self.file_status(fname) in ("", "A", ):
+            return all_regions
+
+        old = self.file_from_head(self.repo_path(fname)).split("\n")
+        new = self.get_file(self.repo_path(fname)).split("\n")
+
+        return modified_regions(old, new, context=context)
+
+
+    def head_revision(self):
+        if self._head_revision is not None:
+            return self._head_revision
+
+        try:
+            self._head_revision = subprocess.check_output(
+                [ self.git, "rev-parse", "--verify", "HEAD" ],
+                stderr=subprocess.PIPE).rstrip("\n")
+        except subprocess.CalledProcessError:
+            # Assume that the repo is empty and use the semi-magic
+            # empty tree revision if git rev-parse returned an error.
+            self._head_revision = "4b825dc642cb6eb9a060e54bf8d69288fbee4904"
+
+        return self._head_revision
+
+    def file_status(self, fname, cached=False):
+        status = self.status(files=[fname], cached=cached)
+        assert len(status) <= 1
+        if status:
+            return status[0][0]
+        else:
+            # No information available for the file. This usually
+            # means that it hasn't been added to the
+            # repository/commit.
+            return ""
+
+    def status(self, filter=None, files=[], cached=False):
+        cmd = [ self.git, "diff-index", "--name-status" ]
+        if cached:
+            cmd.append("--cached")
+        if filter:
+            cmd += [ "--diff-filter", filter ]
+        cmd += [ self.head_revision(), "--" ] + files
+        status = subprocess.check_output(cmd).rstrip("\n")
+
+        if status:
+            return [ f.split("\t") for f in status.split("\n") ]
+        else:
+            return []
+
+    def file_from_index(self, name):
+        return subprocess.check_output(
+            [ self.git, "show", ":%s" % (name, ) ])
+
+    def file_from_head(self, name):
+        return subprocess.check_output(
+            [ self.git, "show", "%s:%s" % (self.head_revision(), name) ])
+
+class MercurialRepo(AbstractRepo):
+    def __init__(self):
+        self.hg = "hg"
+        self._repo_base = None
+
+    def repo_base(self):
+        if self._repo_base is None:
+            self._repo_base = subprocess.check_output(
+                [ self.hg, "root" ]).rstrip("\n")
+
+        return self._repo_base
+
+    def staged_files(self):
+        added = []
+        modified = []
+        for action, fname in self.status():
+            if action == "M":
+                modified.append(fname)
+            elif action == "A":
+                added.append(fname)
+
+        return added, modified
+
+    def staged_regions(self, fname, context=0):
+        return self.modified_regions(fname, context=context)
+
+    def modified_regions(self, fname, context=0):
+        old = self.file_from_tip(fname).split("\n")
+        new = self.get_file(fname).split("\n")
+
+        return modified_regions(old, new, context=context)
+
+    def status(self, filter=None):
+        files = subprocess.check_output([ self.hg, "status" ]).rstrip("\n")
+        if files:
+            return [ f.split(" ") for f in files.split("\n") ]
+        else:
+            return []
+
+    def file_from_tip(self, name):
+        return subprocess.check_output([ self.hg, "cat", name ])
+
+def detect_repo(path="."):
+    """Auto-detect the revision control system used for a source code
+    directory. The code starts searching for repository meta data
+    directories in path and then continues towards the root directory
+    until root is reached or a metadatadirectory has been found.
+
+    Returns: List of repository helper classes that can interface with
+    the detected revision control system(s).
+
+    """
+
+    _repo_types = (
+        (".git", GitRepo),
+        (".hg", MercurialRepo),
+    )
+
+    repo_types = []
+    for repo_dir, repo_class in _repo_types:
+        if os.path.exists(os.path.join(path, repo_dir)):
+            repo_types.append(repo_class)
+
+    if repo_types:
+        return repo_types
+    else:
+        parent_dir = os.path.abspath(os.path.join(path, ".."))
+        if not os.path.samefile(parent_dir, path):
+            return detect_repo(path=parent_dir)
+        else:
+            # We reached the root directory without finding a meta
+            # data directory.
+            return []