diff --git a/tools/releasetools/Android.bp b/tools/releasetools/Android.bp
new file mode 100644
index 0000000..b5ae009
--- /dev/null
+++ b/tools/releasetools/Android.bp
@@ -0,0 +1,72 @@
+// Copyright (C) 2019 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.
+
+python_defaults {
+    name: "releasetools_test_defaults",
+    version: {
+        py2: {
+            enabled: true,
+            embedded_launcher: false,
+        },
+        py3: {
+            enabled: false,
+        },
+    },
+}
+
+python_library_host {
+    name: "releasetools_lib",
+    defaults: ["releasetools_test_defaults"],
+    srcs: [
+        "add_img_to_target_files.py",
+        "apex_utils.py",
+        "blockimgdiff.py",
+        "build_image.py",
+        "build_super_image.py",
+        "check_ota_package_signature.py",
+        "check_target_files_signatures.py",
+        "common.py",
+        "edify_generator.py",
+        "img_from_target_files.py",
+        "make_recovery_patch.py",
+        "merge_target_files.py",
+        "ota_from_target_files.py",
+        "ota_package_parser.py",
+        "rangelib.py",
+        "sign_target_files_apks.py",
+        "sparse_img.py",
+        "target_files_diff.py",
+        "validate_target_files.py",
+        "verity_utils.py",
+    ],
+}
+
+python_test_host {
+    name: "releasetools_test",
+    defaults: ["releasetools_test_defaults"],
+    main: "test_utils.py",
+    srcs: [
+        "test_*.py",
+    ],
+    libs: [
+        "releasetools_lib",
+    ],
+    data: [
+        "testdata/*",
+    ],
+    required: [
+        "otatools",
+    ],
+    test_suites: ["general-tests"],
+}
diff --git a/tools/releasetools/test_apex_utils.py b/tools/releasetools/test_apex_utils.py
index 2f8ee49..76d4d58 100644
--- a/tools/releasetools/test_apex_utils.py
+++ b/tools/releasetools/test_apex_utils.py
@@ -56,8 +56,10 @@
 
   def test_SignApexPayload_withSignerHelper(self):
     payload_file = self._GetTestPayload()
+    signing_helper = os.path.join(self.testdata_dir, 'signing_helper.sh')
+    os.chmod(signing_helper, 0o700)
     payload_signer_args = '--signing_helper_with_files {}'.format(
-        os.path.join(self.testdata_dir, 'signing_helper.sh'))
+        signing_helper)
     apex_utils.SignApexPayload(
         payload_file,
         self.payload_key,
diff --git a/tools/releasetools/test_ota_from_target_files.py b/tools/releasetools/test_ota_from_target_files.py
index 466fde1..bb0236b 100644
--- a/tools/releasetools/test_ota_from_target_files.py
+++ b/tools/releasetools/test_ota_from_target_files.py
@@ -1233,6 +1233,7 @@
     """Uses testdata/payload_signer.sh as the external payload signer."""
     common.OPTIONS.payload_signer = os.path.join(
         self.testdata_dir, 'payload_signer.sh')
+    os.chmod(common.OPTIONS.payload_signer, 0o700)
     common.OPTIONS.payload_signer_args = [
         os.path.join(self.testdata_dir, 'testkey.pk8')]
     payload_signer = PayloadSigner()
diff --git a/tools/releasetools/test_utils.py b/tools/releasetools/test_utils.py
old mode 100644
new mode 100755
index edb3d41..ca127b1
--- a/tools/releasetools/test_utils.py
+++ b/tools/releasetools/test_utils.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python
 #
 # Copyright (C) 2018 The Android Open Source Project
 #
@@ -40,6 +41,19 @@
 
 def get_search_path():
   """Returns the search path that has 'framework/signapk.jar' under."""
+
+  def signapk_exists(path):
+    signapk_path = os.path.realpath(
+        os.path.join(path, 'framework', 'signapk.jar'))
+    return os.path.exists(signapk_path)
+
+  # Try with ANDROID_BUILD_TOP first.
+  full_path = os.path.realpath(os.path.join(
+      os.environ.get('ANDROID_BUILD_TOP', ''), 'out', 'host', 'linux-x86'))
+  if signapk_exists(full_path):
+    return full_path
+
+  # Otherwise try going with relative pathes.
   current_dir = os.path.dirname(os.path.realpath(__file__))
   for path in (
       # In relative to 'build/make/tools/releasetools' in the Android source.
@@ -47,9 +61,7 @@
       # Or running the script unpacked from otatools.zip.
       ['..']):
     full_path = os.path.realpath(os.path.join(current_dir, *path))
-    signapk_path = os.path.realpath(
-        os.path.join(full_path, 'framework', 'signapk.jar'))
-    if os.path.exists(signapk_path):
+    if signapk_exists(full_path):
       return full_path
   return None
 
@@ -123,3 +135,10 @@
 
   def tearDown(self):
     common.Cleanup()
+
+
+if __name__ == '__main__':
+  testsuite = unittest.TestLoader().discover(
+      os.path.dirname(os.path.realpath(__file__)))
+  # atest needs a verbosity level of >= 2 to correctly parse the result.
+  unittest.TextTestRunner(verbosity=2).run(testsuite)