diff --git a/etc/init.rc b/etc/init.rc
index 0fc6c4c..96c37b1 100644
--- a/etc/init.rc
+++ b/etc/init.rc
@@ -22,6 +22,7 @@
     mkdir /data
     mkdir /cache
     mkdir /sideload
+    mkdir /mnt/system
     mount tmpfs tmpfs /tmp
 
     chown root shell /tmp
@@ -87,7 +88,7 @@
 service recovery /sbin/recovery
     seclabel u:r:recovery:s0
 
-service adbd /sbin/adbd --root_seclabel=u:r:su:s0 --device_banner=recovery
+service adbd /system/bin/adbd --root_seclabel=u:r:su:s0 --device_banner=recovery
     disabled
     socket adbd stream 660 system system
     seclabel u:r:adbd:s0
diff --git a/fsck_unshare_blocks.cpp b/fsck_unshare_blocks.cpp
index a100368..2e6b5b8 100644
--- a/fsck_unshare_blocks.cpp
+++ b/fsck_unshare_blocks.cpp
@@ -115,14 +115,6 @@
   return true;
 }
 
-static const char* get_system_root() {
-  if (android::base::GetBoolProperty("ro.build.system_root_image", false)) {
-    return "/system_root";
-  } else {
-    return "/system";
-  }
-}
-
 bool do_fsck_unshare_blocks() {
   // List of partitions we will try to e2fsck -E unshare_blocks.
   std::vector<std::string> partitions = { "/odm", "/oem", "/product", "/vendor" };
@@ -130,10 +122,10 @@
   // Temporarily mount system so we can copy e2fsck_static.
   bool mounted = false;
   if (android::base::GetBoolProperty("ro.build.system_root_image", false)) {
-    mounted = ensure_path_mounted_at("/", "/system_root") != -1;
+    mounted = ensure_path_mounted_at("/", "/mnt/system") != -1;
     partitions.push_back("/");
   } else {
-    mounted = ensure_path_mounted("/system") != -1;
+    mounted = ensure_path_mounted_at("/system", "/mnt/system") != -1;
     partitions.push_back("/system");
   }
   if (!mounted) {
@@ -144,7 +136,7 @@
     LOG(ERROR) << "Could not copy e2fsck to /tmp.";
     return false;
   }
-  if (umount(get_system_root()) < 0) {
+  if (umount("/mnt/system") < 0) {
     PLOG(ERROR) << "umount failed";
     return false;
   }
diff --git a/recovery.cpp b/recovery.cpp
index 98cbfed..fea65ae 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -820,15 +820,13 @@
         break;
       }
       case Device::MOUNT_SYSTEM:
-        // For a system image built with the root directory (i.e. system_root_image == "true"), we
-        // mount it to /system_root, and symlink /system to /system_root/system to make adb shell
-        // work (the symlink is created through the build system). (Bug: 22855115)
+        // the system partition is mounted at /mnt/system
         if (android::base::GetBoolProperty("ro.build.system_root_image", false)) {
-          if (ensure_path_mounted_at("/", "/system_root") != -1) {
+          if (ensure_path_mounted_at("/", "/mnt/system") != -1) {
             ui->Print("Mounted /system.\n");
           }
         } else {
-          if (ensure_path_mounted("/system") != -1) {
+          if (ensure_path_mounted_at("/system", "/mnt/system") != -1) {
             ui->Print("Mounted /system.\n");
           }
         }
diff --git a/updater_sample/Android.mk b/updater_sample/Android.mk
index 7662111..a5deee1 100644
--- a/updater_sample/Android.mk
+++ b/updater_sample/Android.mk
@@ -20,9 +20,8 @@
 LOCAL_PACKAGE_NAME := SystemUpdaterSample
 LOCAL_MODULE_TAGS := samples
 LOCAL_SDK_VERSION := system_current
-
-# TODO: enable proguard and use proguard.flags file
-LOCAL_PROGUARD_ENABLED := disabled
+LOCAL_PRIVILEGED_MODULE := true
+LOCAL_PROGUARD_FLAG_FILES := proguard.flags
 
 LOCAL_SRC_FILES := $(call all-java-files-under, src)
 
diff --git a/updater_sample/proguard.flags b/updater_sample/proguard.flags
new file mode 100644
index 0000000..5883608
--- /dev/null
+++ b/updater_sample/proguard.flags
@@ -0,0 +1,23 @@
+# Copyright (C) 2018 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.
+
+# Keep, used in tests.
+-keep public class com.example.android.systemupdatersample.UpdateManager {
+   public int getUpdaterState();
+}
+
+# Keep, used in tests.
+-keep public class com.example.android.systemupdatersample.UpdateConfig {
+   public <init>(java.lang.String, java.lang.String, int);
+}
diff --git a/updater_sample/tests/Android.mk b/updater_sample/tests/Android.mk
index 9aec372..4157604 100644
--- a/updater_sample/tests/Android.mk
+++ b/updater_sample/tests/Android.mk
@@ -22,10 +22,10 @@
 LOCAL_MODULE_TAGS := tests
 LOCAL_JAVA_LIBRARIES := \
     android.test.base.stubs \
-    android.test.runner.stubs \
-    guava
+    android.test.runner.stubs
 LOCAL_STATIC_JAVA_LIBRARIES := android-support-test \
-    mockito-target-minus-junit4
+    mockito-target-minus-junit4 \
+    guava
 LOCAL_INSTRUMENTATION_FOR := SystemUpdaterSample
 LOCAL_PROGUARD_ENABLED := disabled