diff --git a/hardware.cc b/hardware.cc
new file mode 100644
index 0000000..07901f5
--- /dev/null
+++ b/hardware.cc
@@ -0,0 +1,47 @@
+// Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "update_engine/hardware.h"
+
+#include <base/logging.h>
+#include <rootdev/rootdev.h>
+
+using std::string;
+
+namespace chromeos_update_engine {
+
+const string Hardware::BootDevice() {
+  char boot_path[PATH_MAX];
+  // Resolve the boot device path fully, including dereferencing
+  // through dm-verity.
+  int ret = rootdev(boot_path, sizeof(boot_path), true, false);
+
+  if (ret < 0) {
+    LOG(ERROR) << "rootdev failed to find the root device";
+    return "";
+  }
+  LOG_IF(WARNING, ret > 0) << "rootdev found a device name with no device node";
+
+  // This local variable is used to construct the return string and is not
+  // passed around after use.
+  return boot_path;
+}
+
+const string Hardware::KernelDeviceOfBootDevice(
+    const std::string& boot_device) {
+  // Currently this assumes the last digit of the boot device is
+  // 3, 5, or 7, and changes it to 2, 4, or 6, respectively, to
+  // get the kernel device.
+  string ret = boot_device;
+  if (ret.empty())
+    return ret;
+  char last_char = ret[ret.size() - 1];
+  if (last_char == '3' || last_char == '5' || last_char == '7') {
+    ret[ret.size() - 1] = last_char - 1;
+    return ret;
+  }
+  return "";
+}
+
+}  // namespace chromeos_update_engine