diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index d0d57a9..b27e4c1 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -84,13 +84,25 @@
       pass
 
 
-def LoadInfoDict(zip):
+def LoadInfoDict(input):
   """Read and parse the META/misc_info.txt key/value pairs from the
   input target files and return a dict."""
 
+  def read_helper(fn):
+    if isinstance(input, zipfile.ZipFile):
+      return input.read(fn)
+    else:
+      path = os.path.join(input, *fn.split("/"))
+      try:
+        with open(path) as f:
+          return f.read()
+      except IOError, e:
+        if e.errno == errno.ENOENT:
+          raise KeyError(fn)
+
   d = {}
   try:
-    for line in zip.read("META/misc_info.txt").split("\n"):
+    for line in read_helper("META/misc_info.txt").split("\n"):
       line = line.strip()
       if not line or line.startswith("#"): continue
       k, v = line.split("=", 1)
@@ -105,20 +117,20 @@
 
   if "mkyaffs2_extra_flags" not in d:
     try:
-      d["mkyaffs2_extra_flags"] = zip.read("META/mkyaffs2-extra-flags.txt").strip()
+      d["mkyaffs2_extra_flags"] = read_helper("META/mkyaffs2-extra-flags.txt").strip()
     except KeyError:
       # ok if flags don't exist
       pass
 
   if "recovery_api_version" not in d:
     try:
-      d["recovery_api_version"] = zip.read("META/recovery-api-version.txt").strip()
+      d["recovery_api_version"] = read_helper("META/recovery-api-version.txt").strip()
     except KeyError:
       raise ValueError("can't find recovery API version in input target-files")
 
   if "tool_extensions" not in d:
     try:
-      d["tool_extensions"] = zip.read("META/tool-extensions.txt").strip()
+      d["tool_extensions"] = read_helper("META/tool-extensions.txt").strip()
     except KeyError:
       # ok if extensions don't exist
       pass
@@ -127,7 +139,7 @@
     d["fstab_version"] = "1"
 
   try:
-    data = zip.read("META/imagesizes.txt")
+    data = read_helper("META/imagesizes.txt")
     for line in data.split("\n"):
       if not line: continue
       name, value = line.split(" ", 1)
@@ -152,13 +164,13 @@
   makeint("boot_size")
   makeint("fstab_version")
 
-  d["fstab"] = LoadRecoveryFSTab(zip, d["fstab_version"])
-  d["build.prop"] = LoadBuildProp(zip)
+  d["fstab"] = LoadRecoveryFSTab(read_helper, d["fstab_version"])
+  d["build.prop"] = LoadBuildProp(read_helper)
   return d
 
-def LoadBuildProp(zip):
+def LoadBuildProp(read_helper):
   try:
-    data = zip.read("SYSTEM/build.prop")
+    data = read_helper("SYSTEM/build.prop")
   except KeyError:
     print "Warning: could not find SYSTEM/build.prop in %s" % zip
     data = ""
@@ -171,14 +183,14 @@
     d[name] = value
   return d
 
-def LoadRecoveryFSTab(zip, fstab_version):
+def LoadRecoveryFSTab(read_helper, fstab_version):
   class Partition(object):
     pass
 
   try:
-    data = zip.read("RECOVERY/RAMDISK/etc/recovery.fstab")
+    data = read_helper("RECOVERY/RAMDISK/etc/recovery.fstab")
   except KeyError:
-    print "Warning: could not find RECOVERY/RAMDISK/etc/recovery.fstab in %s." % zip
+    print "Warning: could not find RECOVERY/RAMDISK/etc/recovery.fstab"
     data = ""
 
   if fstab_version == 1:
@@ -973,3 +985,67 @@
       save = True
   cert = "".join(cert).decode('base64')
   return cert
+
+
+def MakeRecoveryPatch(input_dir, output_sink, recovery_img, boot_img):
+  """Generate a binary patch that creates the recovery image starting
+  with the boot image.  (Most of the space in these images is just the
+  kernel, which is identical for the two, so the resulting patch
+  should be efficient.)  Add it to the output zip, along with a shell
+  script that is run from init.rc on first boot to actually do the
+  patching and install the new recovery image.
+
+  recovery_img and boot_img should be File objects for the
+  corresponding images.  info should be the dictionary returned by
+  common.LoadInfoDict() on the input target_files.
+  """
+
+  diff_program = ["imgdiff"]
+  path = os.path.join(input_dir, "SYSTEM", "etc", "recovery-resource.dat")
+  if os.path.exists(path):
+    diff_program.append("-b")
+    diff_program.append(path)
+    bonus_args = "-b /system/etc/recovery-resource.dat"
+  else:
+    bonus_args = ""
+
+  d = Difference(recovery_img, boot_img, diff_program=diff_program)
+  _, _, patch = d.ComputePatch()
+  output_sink("recovery-from-boot.p", patch)
+
+  boot_type, boot_device = GetTypeAndDevice("/boot", OPTIONS.info_dict)
+  recovery_type, recovery_device = GetTypeAndDevice("/recovery", OPTIONS.info_dict)
+
+  sh = """#!/system/bin/sh
+if ! applypatch -c %(recovery_type)s:%(recovery_device)s:%(recovery_size)d:%(recovery_sha1)s; then
+  applypatch %(bonus_args)s %(boot_type)s:%(boot_device)s:%(boot_size)d:%(boot_sha1)s %(recovery_type)s:%(recovery_device)s %(recovery_sha1)s %(recovery_size)d %(boot_sha1)s:/system/recovery-from-boot.p && log -t recovery "Installing new recovery image: succeeded" || log -t recovery "Installing new recovery image: failed"
+else
+  log -t recovery "Recovery image already installed"
+fi
+""" % { 'boot_size': boot_img.size,
+        'boot_sha1': boot_img.sha1,
+        'recovery_size': recovery_img.size,
+        'recovery_sha1': recovery_img.sha1,
+        'boot_type': boot_type,
+        'boot_device': boot_device,
+        'recovery_type': recovery_type,
+        'recovery_device': recovery_device,
+        'bonus_args': bonus_args,
+        }
+
+  # The install script location moved from /system/etc to /system/bin
+  # in the L release.  Parse the init.rc file to find out where the
+  # target-files expects it to be, and put it there.
+  sh_location = "etc/install-recovery.sh"
+  try:
+    with open(os.path.join(input_dir, "BOOT", "RAMDISK", "init.rc")) as f:
+      for line in f:
+        m = re.match("^service flash_recovery /system/(\S+)\s*$", line)
+        if m:
+          sh_location = m.group(1)
+          print "putting script in", sh_location
+          break
+  except (OSError, IOError), e:
+    print "failed to read init.rc: %s" % (e,)
+
+  output_sink(sh_location, sh)
diff --git a/tools/releasetools/make_recovery_patch b/tools/releasetools/make_recovery_patch
new file mode 100755
index 0000000..765063a
--- /dev/null
+++ b/tools/releasetools/make_recovery_patch
@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2014 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 sys
+
+if sys.hexversion < 0x02040000:
+  print >> sys.stderr, "Python 2.4 or newer is required."
+  sys.exit(1)
+
+import os
+import common
+
+OPTIONS = common.OPTIONS
+
+def main(argv):
+  # def option_handler(o, a):
+  #   return False
+
+  args = common.ParseOptions(argv, __doc__)
+  input_dir, output_dir = args
+
+  OPTIONS.info_dict = common.LoadInfoDict(input_dir)
+
+  recovery_img = common.GetBootableImage("recovery.img", "recovery.img",
+                                         input_dir, "RECOVERY")
+  boot_img = common.GetBootableImage("boot.img", "boot.img",
+                                     input_dir, "BOOT")
+
+  def output_sink(fn, data):
+    with open(os.path.join(output_dir, "SYSTEM", *fn.split("/")), "wb") as f:
+      f.write(data)
+
+  common.MakeRecoveryPatch(input_dir, output_sink, recovery_img, boot_img)
+
+
+if __name__ == '__main__':
+  main(sys.argv[1:])
diff --git a/tools/releasetools/ota_from_target_files b/tools/releasetools/ota_from_target_files
index 1174075..652052d 100755
--- a/tools/releasetools/ota_from_target_files
+++ b/tools/releasetools/ota_from_target_files
@@ -352,58 +352,12 @@
   script.AssertDevice(device)
 
 
-def MakeRecoveryPatch(input_tmp, output_zip, recovery_img, boot_img):
-  """Generate a binary patch that creates the recovery image starting
-  with the boot image.  (Most of the space in these images is just the
-  kernel, which is identical for the two, so the resulting patch
-  should be efficient.)  Add it to the output zip, along with a shell
-  script that is run from init.rc on first boot to actually do the
-  patching and install the new recovery image.
-
-  recovery_img and boot_img should be File objects for the
-  corresponding images.  info should be the dictionary returned by
-  common.LoadInfoDict() on the input target_files.
-
-  Returns an Item for the shell script, which must be made
-  executable.
-  """
-
-  diff_program = ["imgdiff"]
-  path = os.path.join(input_tmp, "SYSTEM", "etc", "recovery-resource.dat")
-  if os.path.exists(path):
-    diff_program.append("-b")
-    diff_program.append(path)
-    bonus_args = "-b /system/etc/recovery-resource.dat"
-  else:
-    bonus_args = ""
-
-  d = common.Difference(recovery_img, boot_img, diff_program=diff_program)
-  _, _, patch = d.ComputePatch()
-  common.ZipWriteStr(output_zip, "recovery/recovery-from-boot.p", patch)
-  Item.Get("system/recovery-from-boot.p", dir=False)
-
-  boot_type, boot_device = common.GetTypeAndDevice("/boot", OPTIONS.info_dict)
-  recovery_type, recovery_device = common.GetTypeAndDevice("/recovery", OPTIONS.info_dict)
-
-  sh = """#!/system/bin/sh
-if ! applypatch -c %(recovery_type)s:%(recovery_device)s:%(recovery_size)d:%(recovery_sha1)s; then
-  log -t recovery "Installing new recovery image"
-  applypatch %(bonus_args)s %(boot_type)s:%(boot_device)s:%(boot_size)d:%(boot_sha1)s %(recovery_type)s:%(recovery_device)s %(recovery_sha1)s %(recovery_size)d %(boot_sha1)s:/system/recovery-from-boot.p
-else
-  log -t recovery "Recovery image already installed"
-fi
-""" % { 'boot_size': boot_img.size,
-        'boot_sha1': boot_img.sha1,
-        'recovery_size': recovery_img.size,
-        'recovery_sha1': recovery_img.sha1,
-        'boot_type': boot_type,
-        'boot_device': boot_device,
-        'recovery_type': recovery_type,
-        'recovery_device': recovery_device,
-        'bonus_args': bonus_args,
-        }
-  common.ZipWriteStr(output_zip, "recovery/etc/install-recovery.sh", sh)
-  return Item.Get("system/etc/install-recovery.sh", dir=False)
+def HasRecoveryPatch(target_files_zip):
+  try:
+    target_files_zip.getinfo("SYSTEM/recovery-from-boot.p")
+    return True
+  except KeyError:
+    return False
 
 
 def WriteFullOTAPackage(input_zip, output_zip):
@@ -429,6 +383,8 @@
       metadata=metadata,
       info_dict=OPTIONS.info_dict)
 
+  has_recovery_patch = HasRecoveryPatch(input_zip)
+
   if not OPTIONS.omit_prereq:
     ts = GetBuildProp("ro.build.date.utc", OPTIONS.info_dict)
     ts_text = GetBuildProp("ro.build.date", OPTIONS.info_dict)
@@ -488,7 +444,8 @@
 
   script.FormatPartition("/system")
   script.Mount("/system")
-  script.UnpackPackageDir("recovery", "/system")
+  if not has_recovery_patch:
+    script.UnpackPackageDir("recovery", "/system")
   script.UnpackPackageDir("system", "/system")
 
   symlinks = CopySystemFiles(input_zip, output_zip)
@@ -496,7 +453,14 @@
 
   boot_img = common.GetBootableImage("boot.img", "boot.img",
                                      OPTIONS.input_tmp, "BOOT")
-  MakeRecoveryPatch(OPTIONS.input_tmp, output_zip, recovery_img, boot_img)
+
+  if not has_recovery_patch:
+    def output_sink(fn, data):
+      common.ZipWriteStr(output_zip, "recovery/" + fn, data)
+      Item.Get("system/" + fn, dir=False)
+
+    common.MakeRecoveryPatch(OPTIONS.input_tmp, output_sink,
+                             recovery_img, boot_img)
 
   Item.GetMetadata(input_zip)
   Item.Get("system").SetPermissions(script)
@@ -604,6 +568,8 @@
   print "Loading source..."
   source_data = LoadSystemFiles(source_zip)
 
+  target_has_recovery_patch = HasRecoveryPatch(target_zip)
+
   verbatim_targets = []
   patch_list = []
   diffs = []
@@ -854,10 +820,15 @@
     # For older builds where recovery-resource.dat is not present, we
     # use only the boot image as the source.
 
-    MakeRecoveryPatch(OPTIONS.target_tmp, output_zip,
-                      target_recovery, target_boot)
-    script.DeleteFiles(["/system/recovery-from-boot.p",
-                        "/system/etc/install-recovery.sh"])
+    if not target_has_recovery_patch:
+      def output_sink(fn, data):
+        common.ZipWriteStr(output_zip, "recovery/" + fn, data)
+        Item.Get("system/" + fn, dir=False)
+
+      common.MakeRecoveryPatch(OPTIONS.target_tmp, output_sink,
+                               target_recovery, target_boot)
+      script.DeleteFiles(["/system/recovery-from-boot.p",
+                          "/system/etc/install-recovery.sh"])
     print "recovery image changed; including as patch from boot."
   else:
     print "recovery image unchanged; skipping."
@@ -889,7 +860,7 @@
     script.Print("Unpacking new files...")
     script.UnpackPackageDir("system", "/system")
 
-  if updating_recovery:
+  if updating_recovery and not target_has_recovery_patch:
     script.Print("Unpacking new recovery...")
     script.UnpackPackageDir("recovery", "/system")