diff --git a/src/com/android/phone/EmergencyCallbackModeExitDialog.java b/src/com/android/phone/EmergencyCallbackModeExitDialog.java
index 591f435..adba850 100644
--- a/src/com/android/phone/EmergencyCallbackModeExitDialog.java
+++ b/src/com/android/phone/EmergencyCallbackModeExitDialog.java
@@ -16,6 +16,8 @@
 
 package com.android.phone;
 
+import static android.view.WindowManager.LayoutParams.SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
+
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.Dialog;
@@ -74,7 +76,7 @@
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-
+        getWindow().addPrivateFlags(SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS);
         mPhone = PhoneGlobals.getInstance().getPhoneInEcm();
         // Check if phone is in Emergency Callback Mode. If not, exit.
         if (mPhone == null || !mPhone.isInEcm()) {
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 3bad155..218a79a 100755
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -18,6 +18,8 @@
 
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 
+import static com.android.internal.telephony.PhoneConstants.PHONE_TYPE_CDMA;
+import static com.android.internal.telephony.PhoneConstants.PHONE_TYPE_GSM;
 import static com.android.internal.telephony.PhoneConstants.PHONE_TYPE_IMS;
 import static com.android.internal.telephony.PhoneConstants.SUBSCRIPTION_KEY;
 
@@ -143,6 +145,7 @@
 import com.android.internal.telephony.CommandsInterface;
 import com.android.internal.telephony.DefaultPhoneNotifier;
 import com.android.internal.telephony.GbaManager;
+import com.android.internal.telephony.GsmCdmaPhone;
 import com.android.internal.telephony.HalVersion;
 import com.android.internal.telephony.IBooleanConsumer;
 import com.android.internal.telephony.ICallForwardingInfoCallback;
@@ -8699,6 +8702,31 @@
     }
 
     /**
+     * Start emergency callback mode for GsmCdmaPhone for testing.
+     */
+    @Override
+    public void startEmergencyCallbackMode() {
+        TelephonyPermissions.enforceShellOnly(Binder.getCallingUid(),
+                "startEmergencyCallbackMode");
+        enforceModifyPermission();
+        final long identity = Binder.clearCallingIdentity();
+        try {
+            for (Phone phone : PhoneFactory.getPhones()) {
+                Rlog.d(LOG_TAG, "startEmergencyCallbackMode phone type: " + phone.getPhoneType());
+                if (phone != null && ((phone.getPhoneType() == PHONE_TYPE_GSM)
+                        || (phone.getPhoneType() == PHONE_TYPE_CDMA))) {
+                    GsmCdmaPhone gsmCdmaPhone = (GsmCdmaPhone) phone;
+                    gsmCdmaPhone.obtainMessage(
+                            GsmCdmaPhone.EVENT_EMERGENCY_CALLBACK_MODE_ENTER).sendToTarget();
+                    Rlog.d(LOG_TAG, "startEmergencyCallbackMode: triggered");
+                }
+            }
+        } finally {
+            Binder.restoreCallingIdentity(identity);
+        }
+    }
+
+    /**
      * Update emergency number list for test mode.
      */
     @Override
diff --git a/src/com/android/phone/TelephonyShellCommand.java b/src/com/android/phone/TelephonyShellCommand.java
index ea12984..ba8dec9 100644
--- a/src/com/android/phone/TelephonyShellCommand.java
+++ b/src/com/android/phone/TelephonyShellCommand.java
@@ -71,6 +71,7 @@
     private static final String CALL_COMPOSER_SUBCOMMAND = "callcomposer";
     private static final String IMS_SUBCOMMAND = "ims";
     private static final String NUMBER_VERIFICATION_SUBCOMMAND = "numverify";
+    private static final String EMERGENCY_CALLBACK_MODE = "emergency-callback-mode";
     private static final String EMERGENCY_NUMBER_TEST_MODE = "emergency-number-test-mode";
     private static final String END_BLOCK_SUPPRESSION = "end-block-suppression";
     private static final String RESTART_MODEM = "restart-modem";
@@ -194,6 +195,8 @@
                 return handleRcsUceCommand();
             case NUMBER_VERIFICATION_SUBCOMMAND:
                 return handleNumberVerificationCommand();
+            case EMERGENCY_CALLBACK_MODE:
+                return handleEmergencyCallbackModeCommand();
             case EMERGENCY_NUMBER_TEST_MODE:
                 return handleEmergencyNumberTestModeCommand();
             case CARRIER_CONFIG_SUBCOMMAND: {
@@ -515,6 +518,19 @@
         return 0;
     }
 
+    private int handleEmergencyCallbackModeCommand() {
+        PrintWriter errPw = getErrPrintWriter();
+        try {
+            mInterface.startEmergencyCallbackMode();
+            Log.d(LOG_TAG, "handleEmergencyCallbackModeCommand: triggered");
+        } catch (RemoteException ex) {
+            Log.w(LOG_TAG, "emergency-callback-mode error: " + ex.getMessage());
+            errPw.println("Exception: " + ex.getMessage());
+            return -1;
+        }
+        return 0;
+    }
+
     private int handleEmergencyNumberTestModeCommand() {
         PrintWriter errPw = getErrPrintWriter();
         String opt = getNextOption();