系統服務實際上是呼叫了遠端Bind物件進行操作

1：新增aidl檔案到 framworks/base/core/java/android/hardware/ISerialManager.aidl//這個檔案是需要自己現實的

2：編譯指令碼中新增申明

  frameworks/base/Android.mk:     core/java/android/hardware/ISerialManager.aidl \

3：Context檔案中新增變數

frameworks/base/core/java/android/content/Context.java:    public static final String SERIAL_SERVICE = "serial";

4:新增呼叫遠端服務的檔案

              frameworks/base/services/java/com/android/server/ SerialService.java//這個檔案是需要自己現實的 

          到frameworks/base/services/java/com/android/server/SystemServer.java:

 例如：public class SerialService extends ISerialManager.Stub檔案

  try {
                Slog.i(TAG, "Serial Service");
                // Serial port support
                serial = new SerialService(context);
                ServiceManager.addService(Context.SERIAL_SERVICE, serial);
            } catch (Throwable e) {
                Slog.e(TAG, "Failure starting SerialService", e);
            }

 }

5:添加註冊服務到 frameworks/base/core/java/android/app/ContextImpl.java:  獲取SerialManager

import android.hardware.SerialManager;

import android.hardware.ISerialManager;//這兩個檔案是需要自己現實的 

 構造方法中傳入兩個引數 public SerialManager(Context context, ISerialManager service) {
        mContext = context;
        mService = service;
    }

        registerService(SERIAL_SERVICE, new ServiceFetcher() {
                public Object createService(ContextImpl ctx) {
                    IBinder b = ServiceManager.getService(SERIAL_SERVICE);
                    return new SerialManager(ctx, ISerialManager.Stub.asInterface(b));
                }});

接下來就可以通過(SerialManager)getSystemService(Context.SERIAL_SERVICE);來獲取SerialManager