diff --git a/protos/backup.proto b/protos/backup.proto
index 7ba2937..8ae1752 100644
--- a/protos/backup.proto
+++ b/protos/backup.proto
@@ -37,12 +37,36 @@
   required int64 checksum = 2;
 }
 
+message DeviceProfieData {
+  required float desktop_rows = 1;
+  required float desktop_cols = 2;
+  required float hotseat_count = 3;
+  required int32 allapps_rank = 4;
+}
+
 message Journal {
   required int32 app_version = 1;
+
+  // Time when the backup was created
   required int64 t = 2;
+
+  // Total bytes written during the last backup
+  // OBSOLETE: A state may contain entries which are already present in the backup
+  // and were not written in the last backup
   optional int64 bytes = 3;
+
+  // Total entries written during the last backup
+  // OBSOLETE: A state may contain entries which are already present in the backup
+  // and were not written in the last backup
   optional int32 rows = 4;
+
+  // Valid keys for this state
   repeated Key key = 5;
+
+  // Backup format version.
+  optional int32 backup_version = 6 [default = 1];
+
+  optional DeviceProfieData profile = 7;
 }
 
 message Favorite {
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index b357e7a..bb7265e 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -53,7 +53,6 @@
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Color;
-import android.graphics.Point;
 import android.graphics.PorterDuff;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
@@ -71,7 +70,6 @@
 import android.text.SpannableStringBuilder;
 import android.text.TextUtils;
 import android.text.method.TextKeyListener;
-import android.util.DisplayMetrics;
 import android.util.Log;
 import android.view.Display;
 import android.view.Gravity;
@@ -418,22 +416,9 @@
         LauncherAppState.setApplicationContext(getApplicationContext());
         LauncherAppState app = LauncherAppState.getInstance();
         LauncherAppState.getLauncherProvider().setLauncherProviderChangeListener(this);
-        // Determine the dynamic grid properties
-        Point smallestSize = new Point();
-        Point largestSize = new Point();
-        Point realSize = new Point();
-        Display display = getWindowManager().getDefaultDisplay();
-        display.getCurrentSizeRange(smallestSize, largestSize);
-        display.getRealSize(realSize);
-        DisplayMetrics dm = new DisplayMetrics();
-        display.getMetrics(dm);
 
         // Lazy-initialize the dynamic grid
-        DeviceProfile grid = app.initDynamicGrid(this,
-                Math.min(smallestSize.x, smallestSize.y),
-                Math.min(largestSize.x, largestSize.y),
-                realSize.x, realSize.y,
-                dm.widthPixels, dm.heightPixels);
+        DeviceProfile grid = app.initDynamicGrid(this);
 
         // the LauncherApplication should call this, but in case of Instrumentation it might not be present yet
         mSharedPrefs = getSharedPreferences(LauncherAppState.getSharedPreferencesKey(),
diff --git a/src/com/android/launcher3/LauncherAppState.java b/src/com/android/launcher3/LauncherAppState.java
index 03ab94b..48af216 100644
--- a/src/com/android/launcher3/LauncherAppState.java
+++ b/src/com/android/launcher3/LauncherAppState.java
@@ -25,8 +25,12 @@
 import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.database.ContentObserver;
+import android.graphics.Point;
 import android.os.Handler;
+import android.util.DisplayMetrics;
 import android.util.Log;
+import android.view.Display;
+import android.view.WindowManager;
 
 import com.android.launcher3.compat.LauncherAppsCompat;
 import com.android.launcher3.compat.PackageInstallerCompat;
@@ -190,21 +194,35 @@
         return LauncherFiles.SHARED_PREFERENCES_KEY;
     }
 
-    DeviceProfile initDynamicGrid(Context context, int minWidth, int minHeight,
-                                  int width, int height,
-                                  int availableWidth, int availableHeight) {
+    DeviceProfile initDynamicGrid(Context context) {
+        // Determine the dynamic grid properties
+        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
+        Display display = wm.getDefaultDisplay();
+
+        Point realSize = new Point();
+        display.getRealSize(realSize);
+        DisplayMetrics dm = new DisplayMetrics();
+        display.getMetrics(dm);
+
         if (mDynamicGrid == null) {
+            Point smallestSize = new Point();
+            Point largestSize = new Point();
+            display.getCurrentSizeRange(smallestSize, largestSize);
+
             mDynamicGrid = new DynamicGrid(context,
                     context.getResources(),
-                    minWidth, minHeight, width, height,
-                    availableWidth, availableHeight);
+                    Math.min(smallestSize.x, smallestSize.y),
+                    Math.min(largestSize.x, largestSize.y),
+                    realSize.x, realSize.y,
+                    dm.widthPixels, dm.heightPixels);
             mDynamicGrid.getDeviceProfile().addCallback(this);
         }
 
         // Update the icon size
         DeviceProfile grid = mDynamicGrid.getDeviceProfile();
-        grid.updateFromConfiguration(context, context.getResources(), width, height,
-                availableWidth, availableHeight);
+        grid.updateFromConfiguration(context, context.getResources(),
+                realSize.x, realSize.y,
+                dm.widthPixels, dm.heightPixels);
         return grid;
     }
     public DynamicGrid getDynamicGrid() {
diff --git a/src/com/android/launcher3/LauncherBackupAgentHelper.java b/src/com/android/launcher3/LauncherBackupAgentHelper.java
index 09ad22b..b03b13c 100644
--- a/src/com/android/launcher3/LauncherBackupAgentHelper.java
+++ b/src/com/android/launcher3/LauncherBackupAgentHelper.java
@@ -22,7 +22,6 @@
 import android.content.Context;
 import android.database.Cursor;
 import android.os.ParcelFileDescriptor;
-import android.provider.Settings;
 import android.util.Log;
 
 import java.io.IOException;
@@ -30,13 +29,14 @@
 public class LauncherBackupAgentHelper extends BackupAgentHelper {
 
     private static final String TAG = "LauncherBackupAgentHelper";
+
+    private static final String LAUNCHER_DATA_PREFIX = "L";
+
     static final boolean VERBOSE = true;
     static final boolean DEBUG = false;
 
     private static BackupManager sBackupManager;
 
-    protected static final String SETTING_RESTORE_ENABLED = "launcher_restore_enabled";
-
     /**
      * Notify the backup manager that out database is dirty.
      *
@@ -51,28 +51,13 @@
         sBackupManager.dataChanged();
     }
 
-    @Override
-    public void onDestroy() {
-        // There is only one process accessing this preference file, but the restore
-        // modifies the file outside the normal codepaths, so it looks like another
-        // process.  This forces a reload of the file, in case this process persists.
-        String spKey = LauncherAppState.getSharedPreferencesKey();
-        getSharedPreferences(spKey, Context.MODE_MULTI_PROCESS);
-        super.onDestroy();
-    }
+    private LauncherBackupHelper mHelper;
 
     @Override
     public void onCreate() {
-        boolean restoreEnabled = 0 != Settings.Secure.getInt(
-                getContentResolver(), SETTING_RESTORE_ENABLED, 1);
-        if (VERBOSE) Log.v(TAG, "restore is " + (restoreEnabled ? "enabled" : "disabled"));
-
-        addHelper(LauncherBackupHelper.LAUNCHER_PREFS_PREFIX,
-                new LauncherPreferencesBackupHelper(this,
-                        LauncherAppState.getSharedPreferencesKey(),
-                        restoreEnabled));
-        addHelper(LauncherBackupHelper.LAUNCHER_PREFIX,
-                new LauncherBackupHelper(this, restoreEnabled));
+        super.onCreate();
+        mHelper = new LauncherBackupHelper(this);
+        addHelper(LAUNCHER_DATA_PREFIX, mHelper);
     }
 
     @Override
@@ -92,7 +77,10 @@
         boolean hasData = c.moveToNext();
         c.close();
 
-        if (!hasData) {
+        if (hasData && mHelper.restoreSuccessful) {
+            LauncherAppState.getLauncherProvider().clearFlagEmptyDbCreated();
+            LauncherClings.synchonouslyMarkFirstRunClingDismissed(this);
+        } else {
             if (VERBOSE) Log.v(TAG, "Nothing was restored, clearing DB");
             LauncherAppState.getLauncherProvider().createEmptyDB();
         }
diff --git a/src/com/android/launcher3/LauncherBackupHelper.java b/src/com/android/launcher3/LauncherBackupHelper.java
index b2ac577..8b9c5d9 100644
--- a/src/com/android/launcher3/LauncherBackupHelper.java
+++ b/src/com/android/launcher3/LauncherBackupHelper.java
@@ -40,6 +40,7 @@
 import com.android.launcher3.LauncherSettings.WorkspaceScreens;
 import com.android.launcher3.backup.BackupProtos;
 import com.android.launcher3.backup.BackupProtos.CheckedMessage;
+import com.android.launcher3.backup.BackupProtos.DeviceProfieData;
 import com.android.launcher3.backup.BackupProtos.Favorite;
 import com.android.launcher3.backup.BackupProtos.Journal;
 import com.android.launcher3.backup.BackupProtos.Key;
@@ -66,24 +67,24 @@
  * Persist the launcher home state across calamities.
  */
 public class LauncherBackupHelper implements BackupHelper {
-
     private static final String TAG = "LauncherBackupHelper";
     private static final boolean VERBOSE = LauncherBackupAgentHelper.VERBOSE;
     private static final boolean DEBUG = LauncherBackupAgentHelper.DEBUG;
 
+    private static final int BACKUP_VERSION = 2;
     private static final int MAX_JOURNAL_SIZE = 1000000;
 
+    // Journal key is such that it is always smaller than any dynamically generated
+    // key (any Base64 encoded string).
+    private static final String JOURNAL_KEY = "#";
+
     /** icons are large, dribble them out */
     private static final int MAX_ICONS_PER_PASS = 10;
 
     /** widgets contain previews, which are very large, dribble them out */
     private static final int MAX_WIDGETS_PER_PASS = 5;
 
-    public static final int IMAGE_COMPRESSION_QUALITY = 75;
-
-    public static final String LAUNCHER_PREFIX = "L";
-
-    public static final String LAUNCHER_PREFS_PREFIX = "LP";
+    private static final int IMAGE_COMPRESSION_QUALITY = 75;
 
     private static final Bitmap.CompressFormat IMAGE_FORMAT =
             android.graphics.Bitmap.CompressFormat.PNG;
@@ -145,10 +146,13 @@
     private byte[] mBuffer = new byte[512];
     private long mLastBackupRestoreTime;
 
-    public LauncherBackupHelper(Context context, boolean restoreEnabled) {
+    boolean restoreSuccessful;
+
+    public LauncherBackupHelper(Context context) {
         mContext = context;
         mExistingKeys = new HashSet<String>();
         mKeys = new ArrayList<Key>();
+        restoreSuccessful = true;
     }
 
     private void dataChanged() {
@@ -178,7 +182,6 @@
      * @param oldState notes from the last backup
      * @param data incremental key/value pairs to persist off-device
      * @param newState notes for the next backup
-     * @throws IOException
      */
     @Override
     public void performBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
@@ -220,6 +223,12 @@
 
             mExistingKeys.clear();
             mLastBackupRestoreTime = newBackupTime;
+
+            // We store the journal at two places.
+            //   1) Storing it in newState allows us to do partial backups by comparing old state
+            //   2) Storing it in backup data allows us to validate keys during restore
+            Journal state = getCurrentStateJournal();
+            writeRowToBackup(JOURNAL_KEY, state, data);
         } catch (IOException e) {
             Log.e(TAG, "launcher backup has failed", e);
         }
@@ -228,14 +237,26 @@
     }
 
     /**
+     * @return true if the backup corresponding to oldstate can be successfully applied
+     * to this device.
+     */
+    private boolean isBackupCompatible(Journal oldState) {
+        return true;
+    }
+
+    /**
      * Restore launcher configuration from the restored data stream.
-     *
-     * <P>Keys may arrive in any order.
+     * It assumes that the keys will arrive in lexical order. So if the journal was present in the
+     * backup, it should arrive first.
      *
      * @param data the key/value pair from the server
      */
     @Override
     public void restoreEntity(BackupDataInputStream data) {
+        if (!restoreSuccessful) {
+            return;
+        }
+
         int dataSize = data.size();
         if (mBuffer.length < dataSize) {
             mBuffer = new byte[dataSize];
@@ -244,6 +265,27 @@
             int bytesRead = data.read(mBuffer, 0, dataSize);
             if (DEBUG) Log.d(TAG, "read " + bytesRead + " of " + dataSize + " available");
             String backupKey = data.getKey();
+
+            if (JOURNAL_KEY.equals(backupKey)) {
+                if (VERBOSE) Log.v(TAG, "Journal entry restored");
+                if (!mKeys.isEmpty()) {
+                    // We received the journal key after a restore key.
+                    Log.wtf(TAG, keyToBackupKey(mKeys.get(0)) + " received after " + JOURNAL_KEY);
+                    restoreSuccessful = false;
+                    return;
+                }
+
+                Journal journal = new Journal();
+                MessageNano.mergeFrom(journal, readCheckedBytes(mBuffer, dataSize));
+                applyJournal(journal);
+                restoreSuccessful = isBackupCompatible(journal);
+                return;
+            }
+
+            if (!mExistingKeys.isEmpty() && !mExistingKeys.contains(backupKey)) {
+                if (DEBUG) Log.e(TAG, "Ignoring key not present in the backup state " + backupKey);
+                return;
+            }
             Key key = backupKeyToKey(backupKey);
             mKeys.add(key);
             switch (key.type) {
@@ -288,6 +330,8 @@
         journal.t = mLastBackupRestoreTime;
         journal.key = mKeys.toArray(new BackupProtos.Key[mKeys.size()]);
         journal.appVersion = getAppVersion();
+        journal.backupVersion = BACKUP_VERSION;
+        journal.profile = getDeviceProfieData();
         return journal;
     }
 
@@ -301,6 +345,29 @@
     }
 
     /**
+     * @return the current device profile information.
+     */
+    private DeviceProfieData getDeviceProfieData() {
+        LauncherAppState.setApplicationContext(mContext.getApplicationContext());
+        LauncherAppState app = LauncherAppState.getInstance();
+
+        DeviceProfile profile;
+        if (app.getDynamicGrid() == null) {
+            // Initialize the grid
+            profile = app.initDynamicGrid(mContext);
+        } else {
+            profile = app.getDynamicGrid().getDeviceProfile();
+        }
+
+        DeviceProfieData data = new DeviceProfieData();
+        data.desktopRows = profile.numRows;
+        data.desktopCols = profile.numColumns;
+        data.hotseatCount = profile.numHotseatIcons;
+        data.allappsRank = profile.hotseatAllAppsRank;
+        return data;
+    }
+
+    /**
      * Write all modified favorites to the data stream.
      *
      * @param data output stream for key/value pairs
@@ -902,7 +969,6 @@
         return journal;
     }
 
-
     private void writeRowToBackup(Key key, MessageNano proto, BackupDataOutput data)
             throws IOException {
         writeRowToBackup(keyToBackupKey(key), proto, data);
diff --git a/src/com/android/launcher3/LauncherPreferencesBackupHelper.java b/src/com/android/launcher3/LauncherPreferencesBackupHelper.java
deleted file mode 100644
index 6f9c05c..0000000
--- a/src/com/android/launcher3/LauncherPreferencesBackupHelper.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * 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.
- */
-
-package com.android.launcher3;
-
-import android.app.backup.BackupDataInputStream;
-import android.app.backup.SharedPreferencesBackupHelper;
-import android.content.Context;
-import android.util.Log;
-
-public class LauncherPreferencesBackupHelper extends SharedPreferencesBackupHelper {
-
-    private static final String TAG = "LauncherPreferencesBackupHelper";
-    private static final boolean VERBOSE = LauncherBackupAgentHelper.VERBOSE;
-
-    private final boolean mRestoreEnabled;
-
-    public LauncherPreferencesBackupHelper(Context context,  String sharedPreferencesKey,
-            boolean restoreEnabled) {
-        super(context, sharedPreferencesKey);
-        mRestoreEnabled = restoreEnabled;
-    }
-
-    @Override
-    public void restoreEntity(BackupDataInputStream data) {
-        if (mRestoreEnabled) {
-            if (VERBOSE) Log.v(TAG, "restoring preferences");
-            super.restoreEntity(data);
-        }
-    }
-}
diff --git a/src/com/android/launcher3/LauncherProvider.java b/src/com/android/launcher3/LauncherProvider.java
index fe9bc17..365d989 100644
--- a/src/com/android/launcher3/LauncherProvider.java
+++ b/src/com/android/launcher3/LauncherProvider.java
@@ -293,6 +293,14 @@
         mOpenHelper.createEmptyDB(mOpenHelper.getWritableDatabase());
     }
 
+    public void clearFlagEmptyDbCreated() {
+        String spKey = LauncherAppState.getSharedPreferencesKey();
+        getContext().getSharedPreferences(spKey, Context.MODE_PRIVATE)
+            .edit()
+            .remove(EMPTY_DATABASE_CREATED)
+            .commit();
+    }
+
     /**
      * Loads the default workspace based on the following priority scheme:
      *   1) From a package provided by play store
@@ -334,7 +342,7 @@
                 mOpenHelper.loadFavorites(mOpenHelper.getWritableDatabase(),
                         getDefaultLayoutParser());
             }
-            sp.edit().remove(EMPTY_DATABASE_CREATED).commit();
+            clearFlagEmptyDbCreated();
         }
     }