diff --git a/core/api/current.txt b/core/api/current.txt
index 28b7f9b79d490..92441e0e4c403 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -40334,6 +40334,7 @@ package android.telephony {
     field public static final String KEY_SIMPLIFIED_NETWORK_SETTINGS_BOOL = "simplified_network_settings_bool";
     field public static final String KEY_SIM_NETWORK_UNLOCK_ALLOW_DISMISS_BOOL = "sim_network_unlock_allow_dismiss_bool";
     field public static final String KEY_SMS_REQUIRES_DESTINATION_NUMBER_CONVERSION_BOOL = "sms_requires_destination_number_conversion_bool";
+    field public static final String KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL = "store_sim_pin_for_unattended_reboot_bool";
     field public static final String KEY_SUPPORTS_CALL_COMPOSER_BOOL = "supports_call_composer_bool";
     field public static final String KEY_SUPPORT_3GPP_CALL_FORWARDING_WHILE_ROAMING_BOOL = "support_3gpp_call_forwarding_while_roaming_bool";
     field public static final String KEY_SUPPORT_ADD_CONFERENCE_PARTICIPANTS_BOOL = "support_add_conference_participants_bool";
diff --git a/core/api/system-current.txt b/core/api/system-current.txt
index 5bb3e05170329..058e5a872b6ae 100644
--- a/core/api/system-current.txt
+++ b/core/api/system-current.txt
@@ -11869,6 +11869,7 @@ package android.telephony {
     method @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public boolean matchesCurrentSimOperator(@NonNull String, int, @Nullable String);
     method public boolean needsOtaServiceProvisioning();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void notifyOtaEmergencyNumberDbInstalled();
+    method @RequiresPermission(android.Manifest.permission.REBOOT) public int prepareForUnattendedReboot();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean rebootRadio();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void reportDefaultNetworkStatus(boolean);
     method @RequiresPermission(allOf={android.Manifest.permission.ACCESS_FINE_LOCATION, android.Manifest.permission.MODIFY_PHONE_STATE}) public void requestCellInfoUpdate(@NonNull android.os.WorkSource, @NonNull java.util.concurrent.Executor, @NonNull android.telephony.TelephonyManager.CellInfoCallback);
@@ -11993,6 +11994,9 @@ package android.telephony {
     field public static final int NR_DUAL_CONNECTIVITY_DISABLE = 2; // 0x2
     field public static final int NR_DUAL_CONNECTIVITY_DISABLE_IMMEDIATE = 3; // 0x3
     field public static final int NR_DUAL_CONNECTIVITY_ENABLE = 1; // 0x1
+    field public static final int PREPARE_UNATTENDED_REBOOT_ERROR = 2; // 0x2
+    field public static final int PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED = 1; // 0x1
+    field public static final int PREPARE_UNATTENDED_REBOOT_SUCCESS = 0; // 0x0
     field public static final int RADIO_POWER_OFF = 0; // 0x0
     field public static final int RADIO_POWER_ON = 1; // 0x1
     field public static final int RADIO_POWER_UNAVAILABLE = 2; // 0x2
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 25e7951efe284..2f63bf81d0198 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -4707,4 +4707,10 @@
 
     <!-- Whether to select voice/data/sms preference without user confirmation -->
     <bool name="config_voice_data_sms_auto_fallback">false</bool>
+
+    <!-- Whether to enable the one-handed keyguard on the lock screen for wide-screen devices. -->
+    <bool name="config_enableOneHandedKeyguard">false</bool>
+
+    <!-- Whether to allow the caching of the SIM PIN for verification after unattended reboot -->
+    <bool name="config_allow_pin_storage_for_unattended_reboot">true</bool>
 </resources>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index 9a165bb6fc302..eb853de5bfab4 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -2647,6 +2647,7 @@
   <java-symbol type="bool" name="config_defaultWindowFeatureContextMenu" />
   <java-symbol type="bool" name="config_overrideRemoteViewsActivityTransition" />
   <java-symbol type="attr" name="colorProgressBackgroundNormal" />
+  <java-symbol type="bool" name="config_allow_pin_storage_for_unattended_reboot" />
 
   <java-symbol type="layout" name="simple_account_item" />
   <java-symbol type="string" name="prohibit_manual_network_selection_in_gobal_mode" />
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index ac584c175c59d..21cf3e57115d0 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -4748,6 +4748,21 @@ public class CarrierConfigManager {
     public static final String KEY_NETWORK_TEMP_NOT_METERED_SUPPORTED_BOOL =
             "network_temp_not_metered_supported_bool";
 
+    /*
+     * Boolean indicating whether the SIM PIN can be stored and verified
+     * seamlessly after an unattended reboot.
+     *
+     * The device configuration value {@code config_allow_pin_storage_for_unattended_reboot}
+     * ultimately controls whether this carrier configuration option is used.  Where
+     * {@code config_allow_pin_storage_for_unattended_reboot} is false, the value of the
+     * {@link #KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL} carrier configuration option is
+     * ignored.
+     *
+     * @hide
+     */
+    public static final String KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL =
+            "store_sim_pin_for_unattended_reboot_bool";
+
     /** The default value for every variable. */
     private final static PersistableBundle sDefaults;
 
@@ -5304,6 +5319,7 @@ public class CarrierConfigManager {
         sDefaults.putBoolean(KEY_USE_ACS_FOR_RCS_BOOL, false);
         sDefaults.putBoolean(KEY_NETWORK_TEMP_NOT_METERED_SUPPORTED_BOOL, true);
         sDefaults.putInt(KEY_DEFAULT_RTT_MODE_INT, 0);
+        sDefaults.putBoolean(KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL, true);
     }
 
     /**
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 65b8de2b22168..441446cdc48da 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -14994,6 +14994,7 @@ public class TelephonyManager {
         }
         return THERMAL_MITIGATION_RESULT_UNKNOWN_ERROR;
     }
+
     /**
      * Registers a listener object to receive notification of changes
      * in specified telephony states.
@@ -15350,4 +15351,66 @@ public class TelephonyManager {
             return PhoneCapability.DEFAULT_SSSS_CAPABILITY;
         }
     }
+
+    /**
+     * The unattended reboot was prepared successfully.
+     * @hide
+     */
+    @SystemApi
+    public static final int PREPARE_UNATTENDED_REBOOT_SUCCESS = 0;
+
+    /**
+     * The unattended reboot was prepared, but the user will need to manually
+     * enter the PIN code of at least one SIM card present in the device.
+     * @hide
+     */
+    @SystemApi
+    public static final int PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED = 1;
+
+    /**
+     * The unattended reboot was not prepared due to generic error.
+     * @hide
+     */
+    @SystemApi
+    public static final int PREPARE_UNATTENDED_REBOOT_ERROR = 2;
+
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(prefix = {"PREPARE_UNATTENDED_REBOOT_"},
+            value = {
+                    PREPARE_UNATTENDED_REBOOT_SUCCESS,
+                    PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED,
+                    PREPARE_UNATTENDED_REBOOT_ERROR
+            })
+    public @interface PrepareUnattendedRebootResult {}
+
+    /**
+     * Prepare TelephonyManager for an unattended reboot. The reboot is required to be done
+     * shortly (e.g. within 15 seconds) after the API is invoked.
+     *
+     * <p>Requires Permission:
+     *   {@link android.Manifest.permission#REBOOT}
+     *
+     * @return {@link #PREPARE_UNATTENDED_REBOOT_SUCCESS} in case of success.
+     * {@link #PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED} if the device contains
+     * at least one SIM card for which the user needs to manually enter the PIN
+     * code after the reboot. {@link #PREPARE_UNATTENDED_REBOOT_ERROR} in case
+     * of error.
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(android.Manifest.permission.REBOOT)
+    @PrepareUnattendedRebootResult
+    public int prepareForUnattendedReboot() {
+        try {
+            ITelephony service = getITelephony();
+            if (service != null) {
+                return service.prepareForUnattendedReboot();
+            }
+        } catch (RemoteException e) {
+            Log.e(TAG, "Telephony#prepareForUnattendedReboot RemoteException", e);
+            e.rethrowFromSystemServer();
+        }
+        return PREPARE_UNATTENDED_REBOOT_ERROR;
+    }
 }
diff --git a/telephony/java/com/android/internal/telephony/ITelephony.aidl b/telephony/java/com/android/internal/telephony/ITelephony.aidl
index 0cd17da3c0c5e..1d049530ba774 100644
--- a/telephony/java/com/android/internal/telephony/ITelephony.aidl
+++ b/telephony/java/com/android/internal/telephony/ITelephony.aidl
@@ -2387,4 +2387,18 @@ interface ITelephony {
      * Gets the current phone capability.
      */
     PhoneCapability getPhoneCapability();
+
+    /**
+     * Prepare TelephonyManager for an unattended reboot. The reboot is
+     * required to be done shortly after the API is invoked.
+     *
+     * Requires system privileges.
+     *
+     * @return {@link #PREPARE_UNATTENDED_REBOOT_SUCCESS} in case of success.
+     * {@link #PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED} if the device contains
+     * at least one SIM card for which the user needs to manually enter the PIN
+     * code after the reboot. {@link #PREPARE_UNATTENDED_REBOOT_ERROR} in case
+     * of error.
+     */
+    int prepareForUnattendedReboot();
 }