diff --git a/tools/releasetools/amend_generator.py b/tools/releasetools/amend_generator.py
new file mode 100644
index 0000000..8341599
--- /dev/null
+++ b/tools/releasetools/amend_generator.py
@@ -0,0 +1,205 @@
+# Copyright (C) 2009 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+
+import common
+
+class AmendGenerator(object):
+  """Class to generate scripts in the 'amend' recovery script language
+  used up through cupcake."""
+
+  def __init__(self):
+    self.script = ['assert compatible_with("0.2") == "true"']
+    self.included_files = set()
+
+  def MakeTemporary(self):
+    """Make a temporary script object whose commands can latter be
+    appended to the parent script with AppendScript().  Used when the
+    caller wants to generate script commands out-of-order."""
+    x = AmendGenerator()
+    x.script = []
+    x.included_files = self.included_files
+    return x
+
+  @staticmethod
+  def _FileRoot(fn):
+    """Convert a file path to the 'root' notation used by amend."""
+    if fn.startswith("/system/"):
+      return "SYSTEM:" + fn[8:]
+    elif fn == "/system":
+      return "SYSTEM:"
+    elif fn.startswith("/tmp/"):
+      return "CACHE:.." + fn
+    else:
+      raise ValueError("don't know root for \"%s\"" % (fn,))
+
+  @staticmethod
+  def _PartitionRoot(partition):
+    """Convert a partition name to the 'root' notation used by amend."""
+    if partition == "userdata":
+      return "DATA:"
+    else:
+      return partition.upper() + ":"
+
+  def AppendScript(self, other):
+    """Append the contents of another script (which should be created
+    with temporary=True) to this one."""
+    self.script.extend(other.script)
+    self.included_files.update(other.included_files)
+
+  def AssertSomeFingerprint(self, *fp):
+    """Assert that the current fingerprint is one of *fp."""
+    x = [('file_contains("SYSTEM:build.prop", '
+          '"ro.build.fingerprint=%s") == "true"') % i for i in fp]
+    self.script.append("assert %s" % (" || ".join(x),))
+
+  def AssertOlderBuild(self, timestamp):
+    """Assert that the build on the device is older (or the same as)
+    the given timestamp."""
+    self.script.append("run_program PACKAGE:check_prereq %s" % (timestamp,))
+    self.included_files.add("check_prereq")
+
+  def AssertDevice(self, device):
+    """Assert that the device identifier is the given string."""
+    self.script.append('assert getprop("ro.product.device") == "%s" || '
+                       'getprop("ro.build.product") == "%s"' % (device, device))
+
+  def AssertSomeBootloader(self, *bootloaders):
+    """Asert that the bootloader version is one of *bootloaders."""
+    self.script.append("assert " +
+                  " || ".join(['getprop("ro.bootloader") == "%s"' % (b,)
+                               for b in bootloaders]))
+
+  def ShowProgress(self, frac, dur):
+    """Update the progress bar, advancing it over 'frac' over the next
+    'dur' seconds."""
+    self.script.append("show_progress %f %d" % (frac, int(dur)))
+
+  def PatchCheck(self, filename, *sha1):
+    """Check that the given file (or MTD reference) has one of the
+    given *sha1 hashes."""
+    out = ["run_program PACKAGE:applypatch -c %s" % (filename,)]
+    for i in sha1:
+      out.append(" " + i)
+    self.script.append("".join(out))
+    self.included_files.add("applypatch")
+
+  def CacheFreeSpaceCheck(self, amount):
+    """Check that there's at least 'amount' space that can be made
+    available on /cache."""
+    self.script.append("run_program PACKAGE:applypatch -s %d" % (amount,))
+    self.included_files.add("applypatch")
+
+  def Mount(self, kind, what, path):
+    # no-op; amend uses it's 'roots' system to automatically mount
+    # things when they're referred to
+    pass
+
+  def UnpackPackageDir(self, src, dst):
+    """Unpack a given directory from the OTA package into the given
+    destination directory."""
+    dst = self._FileRoot(dst)
+    self.script.append("copy_dir PACKAGE:%s %s" % (src, dst))
+
+  def Comment(self, comment):
+    """Write a comment into the update script."""
+    self.script.append("")
+    for i in comment.split("\n"):
+      self.script.append("# " + i)
+    self.script.append("")
+
+  def Print(self, message):
+    """Log a message to the screen (if the logs are visible)."""
+    # no way to do this from amend; substitute a script comment instead
+    self.Comment(message)
+
+  def FormatPartition(self, partition):
+    """Format the given MTD partition."""
+    self.script.append("format %s" % (self._PartitionRoot(partition),))
+
+  def DeleteFiles(self, file_list):
+    """Delete all files in file_list."""
+    line = []
+    t = 0
+    for i in file_list:
+      i = self._FileRoot(i)
+      line.append(i)
+      t += len(i) + 1
+      if t > 80:
+        self.script.append("delete " + " ".join(line))
+        line = []
+        t = 0
+    if line:
+      self.script.append("delete " + " ".join(line))
+
+  def ApplyPatch(self, srcfile, tgtfile, tgtsize, tgtsha1, *patchpairs):
+    """Apply binary patches (in *patchpairs) to the given srcfile to
+    produce tgtfile (which may be "-" to indicate overwriting the
+    source file."""
+    if len(patchpairs) % 2 != 0:
+      raise ValueError("bad patches given to ApplyPatch")
+    self.script.append(
+        ("run_program PACKAGE:applypatch %s %s %s %d " %
+         (srcfile, tgtfile, tgtsha1, tgtsize)) +
+        " ".join(["%s:%s" % patchpairs[i:i+2]
+                  for i in range(0, len(patchpairs), 2)]))
+    self.included_files.add("applypatch")
+
+  def WriteFirmwareImage(self, kind, fn):
+    """Arrange to update the given firmware image (kind must be
+    "hboot" or "radio") when recovery finishes."""
+    self.script.append("write_%s_image PACKAGE:%s" % (kind, fn))
+
+  def WriteRawImage(self, partition, fn):
+    """Write the given file into the given MTD partition."""
+    self.script.append("write_raw_image PACKAGE:%s %s" %
+                       (fn, self._PartitionRoot(partition)))
+
+  def SetPermissions(self, fn, uid, gid, mode):
+    """Set file ownership and permissions."""
+    fn = self._FileRoot(fn)
+    self.script.append("set_perm %d %d 0%o %s" % (uid, gid, mode, fn))
+
+  def SetPermissionsRecursive(self, fn, uid, gid, dmode, fmode):
+    """Recursively set path ownership and permissions."""
+    fn = self._FileRoot(fn)
+    self.script.append("set_perm_recursive %d %d 0%o 0%o %s" %
+                       (uid, gid, dmode, fmode, fn))
+
+  def MakeSymlinks(self, symlink_list):
+    """Create symlinks, given a list of (dest, link) pairs."""
+    self.script.extend(["symlink %s %s" % (i[0], self._FileRoot(i[1]))
+                        for i in sorted(symlink_list)])
+
+  def AppendExtra(self, extra):
+    """Append text verbatim to the output script."""
+    self.script.append(extra)
+
+  def AddToZip(self, input_zip, output_zip, input_path=None):
+    """Write the accumulated script to the output_zip file.  input_zip
+    is used as the source for any ancillary binaries needed by the
+    script.  If input_path is not None, it will be used as a local
+    path for binaries instead of input_zip."""
+    common.ZipWriteStr(output_zip, "META-INF/com/google/android/update-script",
+                       "\n".join(self.script) + "\n")
+    for i in self.included_files:
+      try:
+        if input_path is None:
+          data = input_zip.read(os.path.join("OTA/bin", i))
+        else:
+          data = open(os.path.join(input_path, i)).read()
+        common.ZipWriteStr(output_zip, i, data, perms=0755)
+      except (IOError, KeyError), e:
+        raise ExternalError("unable to include binary %s: %s" % (i, e))