diff --git a/utils.cc b/utils.cc
new file mode 100644
index 0000000..693062d
--- /dev/null
+++ b/utils.cc
@@ -0,0 +1,253 @@
+// Copyright (c) 2009 The Chromium 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/utils.h"
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <algorithm>
+#include "chromeos/obsolete_logging.h"
+
+using std::min;
+using std::string;
+using std::vector;
+
+namespace chromeos_update_engine {
+
+namespace utils {
+
+bool ReadFile(const std::string& path, std::vector<char>* out) {
+  CHECK(out);
+  FILE* fp = fopen(path.c_str(), "r");
+  if (!fp)
+    return false;
+  const size_t kChunkSize = 1024;
+  size_t read_size;
+  do {
+    char buf[kChunkSize];
+    read_size = fread(buf, 1, kChunkSize, fp);
+    if (read_size == 0)
+      break;
+    out->insert(out->end(), buf, buf + read_size);
+  } while (read_size == kChunkSize);
+  bool success = !ferror(fp);
+  TEST_AND_RETURN_FALSE_ERRNO(fclose(fp) == 0);
+  return success;
+}
+
+bool ReadFileToString(const std::string& path, std::string* out) {
+  vector<char> data;
+  bool success = ReadFile(path, &data);
+  if (!success) {
+    return false;
+  }
+  (*out) = string(&data[0], data.size());
+  return true;
+}
+
+void HexDumpArray(const unsigned char* const arr, const size_t length) {
+  const unsigned char* const char_arr =
+      reinterpret_cast<const unsigned char* const>(arr);
+  LOG(INFO) << "Logging array of length: " << length;
+  const unsigned int bytes_per_line = 16;
+  for (size_t i = 0; i < length; i += bytes_per_line) {
+    const unsigned int bytes_remaining = length - i;
+    const unsigned int bytes_per_this_line = min(bytes_per_line,
+                                                 bytes_remaining);
+    char header[100];
+    int r = snprintf(header, sizeof(header), "0x%08x : ", i);
+    TEST_AND_RETURN(r == 13);
+    string line = header;
+    for (unsigned int j = 0; j < bytes_per_this_line; j++) {
+      char buf[20];
+      unsigned char c = char_arr[i + j];
+      r = snprintf(buf, sizeof(buf), "%02x ", static_cast<unsigned int>(c));
+      TEST_AND_RETURN(r == 3);
+      line += buf;
+    }
+    LOG(INFO) << line;
+  }
+}
+
+namespace {
+class ScopedDirCloser {
+ public:
+  explicit ScopedDirCloser(DIR** dir) : dir_(dir) {}
+  ~ScopedDirCloser() {
+    if (dir_ && *dir_) {
+      int r = closedir(*dir_);
+      TEST_AND_RETURN_ERRNO(r == 0);
+      *dir_ = NULL;
+      dir_ = NULL;
+    }
+  }
+ private:
+  DIR** dir_;
+};
+}  // namespace {}
+
+bool RecursiveUnlinkDir(const std::string& path) {
+  struct stat stbuf;
+  int r = lstat(path.c_str(), &stbuf);
+  TEST_AND_RETURN_FALSE_ERRNO((r == 0) || (errno == ENOENT));
+  if ((r < 0) && (errno == ENOENT))
+    // path request is missing. that's fine.
+    return true;
+  if (!S_ISDIR(stbuf.st_mode)) {
+    TEST_AND_RETURN_FALSE_ERRNO((unlink(path.c_str()) == 0) ||
+                                 (errno == ENOENT));
+    // success or path disappeared before we could unlink.
+    return true;
+  }
+  {
+    // We have a dir, unlink all children, then delete dir
+    DIR *dir = opendir(path.c_str());
+    TEST_AND_RETURN_FALSE_ERRNO(dir);
+    ScopedDirCloser dir_closer(&dir);
+    struct dirent dir_entry;
+    struct dirent *dir_entry_p;
+    int err = 0;
+    while ((err = readdir_r(dir, &dir_entry, &dir_entry_p)) == 0) {
+      if (dir_entry_p == NULL) {
+        // end of stream reached
+        break;
+      }
+      // Skip . and ..
+      if (!strcmp(dir_entry_p->d_name, ".") ||
+          !strcmp(dir_entry_p->d_name, ".."))
+        continue;
+      TEST_AND_RETURN_FALSE(RecursiveUnlinkDir(path + "/" +
+                                                dir_entry_p->d_name));
+    }
+    TEST_AND_RETURN_FALSE(err == 0);
+  }
+  // unlink dir
+  TEST_AND_RETURN_FALSE_ERRNO((rmdir(path.c_str()) == 0) || (errno == ENOENT));
+  return true;
+}
+
+std::string ErrnoNumberAsString(int err) {
+  char buf[100];
+  buf[0] = '\0';
+  return strerror_r(err, buf, sizeof(buf));
+}
+
+std::string NormalizePath(const std::string& path, bool strip_trailing_slash) {
+  string ret;
+  bool last_insert_was_slash = false;
+  for (string::const_iterator it = path.begin(); it != path.end(); ++it) {
+    if (*it == '/') {
+      if (last_insert_was_slash)
+        continue;
+      last_insert_was_slash = true;
+    } else {
+      last_insert_was_slash = false;
+    }
+    ret.push_back(*it);
+  }
+  if (strip_trailing_slash && last_insert_was_slash) {
+    string::size_type last_non_slash = ret.find_last_not_of('/');
+    if (last_non_slash != string::npos) {
+      ret.resize(last_non_slash + 1);
+    } else {
+      ret = "";
+    }
+  }
+  return ret;
+}
+
+bool FileExists(const char* path) {
+  struct stat stbuf;
+  return 0 == lstat(path, &stbuf);
+}
+
+std::string TempFilename(string path) {
+  static const string suffix("XXXXXX");
+  CHECK(StringHasSuffix(path, suffix));
+  do {
+    string new_suffix;
+    for (unsigned int i = 0; i < suffix.size(); i++) {
+      int r = rand() % (26 * 2 + 10);  // [a-zA-Z0-9]
+      if (r < 26)
+        new_suffix.append(1, 'a' + r);
+      else if (r < (26 * 2))
+        new_suffix.append(1, 'A' + r - 26);
+      else
+        new_suffix.append(1, '0' + r - (26 * 2));
+    }
+    CHECK_EQ(new_suffix.size(), suffix.size());
+    path.resize(path.size() - new_suffix.size());
+    path.append(new_suffix);
+  } while (FileExists(path.c_str()));
+  return path;
+}
+
+bool StringHasSuffix(const std::string& str, const std::string& suffix) {
+  if (suffix.size() > str.size())
+    return false;
+  return 0 == str.compare(str.size() - suffix.size(), suffix.size(), suffix);
+}
+
+bool StringHasPrefix(const std::string& str, const std::string& prefix) {
+  if (prefix.size() > str.size())
+    return false;
+  return 0 == str.compare(0, prefix.size(), prefix);
+}
+
+const std::string BootDevice() {
+  string proc_cmdline;
+  if (!ReadFileToString("/proc/cmdline", &proc_cmdline))
+    return "";
+  // look for "root=" in the command line
+  string::size_type pos = 0;
+  if (!StringHasPrefix(proc_cmdline, "root=")) {
+    pos = proc_cmdline.find(" root=") + 1;
+  }
+  if (pos == string::npos) {
+    // can't find root=
+    return "";
+  }
+  // at this point, pos is the point in the string where "root=" starts
+  string ret;
+  pos += strlen("root=");  // advance to the device name itself
+  while (pos < proc_cmdline.size()) {
+    char c = proc_cmdline[pos];
+    if (c == ' ')
+      break;
+    ret += c;
+    pos++;
+  }
+  return ret;
+  // TODO(adlr): use findfs to figure out UUID= or LABEL= filesystems
+}
+
+bool MountFilesystem(const string& device,
+                     const string& mountpoint) {
+  int rc = mount(device.c_str(), mountpoint.c_str(), "ext3", 0, NULL);
+  if (rc < 0) {
+    string msg = ErrnoNumberAsString(errno);
+    LOG(ERROR) << "Unable to mount destination device: " << msg << ". "
+               << device << " on " << mountpoint;
+    return false;
+  }
+  return true;
+}
+
+bool UnmountFilesystem(const string& mountpoint) {
+  TEST_AND_RETURN_FALSE_ERRNO(umount(mountpoint.c_str()) == 0);
+  return true;
+}
+
+const string kStatefulPartition = "/mnt/stateful_partition";
+
+}  // namespace utils
+
+}  // namespace chromeos_update_engine
+