framework层修改：
t0_sys/frameworks/base/core/api/current.txt

     method @RequiresPermission(android.Manifest.permission.REBOOT) public void reboot(@Nullable String);
+    method public void rebootp();

t0_sys/frameworks/base/core/java/android/os/IPowerManager.aidl

+void rebootp();

t0_sys/frameworks/base/core/java/android/os/PowerManager.java

+    public void rebootp(){
+        try{
+             mService.rebootp();
+        } catch (RemoteException e){
+            throw e.rethrowFromSystemServer();
+        }
+    }
+

t0_sys/frameworks/base/services/core/java/com/android/server/power/PowerManagerService.java

+import java.io.IOException;+        @Override // Binder call
+        public void rebootp(){
+            try {
+                  Runtime.getRuntime().exec("reboot -p");   //关机
+                } catch (IOException e) {
+                e.printStackTrace();
+                }
+        }

由于添加了系统API，执行lunch后，先执行 make update-api 命令更新系统API 后再执行 make -j24编译源码

APP使用反射调用关机接口
1.编写反射接口

public class PowerManagerUtils {private static final String CLASS = "android.os.PowerManager";private static final String UART_POWER_OPEN = "rebootp";public static void open(PowerManager manager) {try {Class<?> spClass = Class.forName(CLASS);Method getMethod = spClass.getMethod(UART_POWER_OPEN);getMethod.invoke(manager);} catch (ClassNotFoundException e) {e.printStackTrace();} catch (NoSuchMethodException e) {e.printStackTrace();} catch (IllegalArgumentException e) {e.printStackTrace();} catch (IllegalAccessException e) {e.printStackTrace();} catch (InvocationTargetException e) {e.printStackTrace();}}

2.调用反射执行PowerManager类中的rebootp方法

PowerManager powerManager;
powerManager = (PowerManager) getSystemService(POWER_SERVICE);
PowerManagerUtils.open(powerManager);