基于Dragonboard 410c的指纹锁（七）

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       继续研究fingerprint在Android中的添加。上篇中HAL层的实现算是找到了，但是不知道是不是真的是这个，也不知道有没有被应用，既然驱动没有，那就往上看吧。

      开机时会开启各种服务，我们从开始启动指纹识别的service开始。

     路径：

    framework/base/services/java/com/android/server/SystemServer.java

   

private void run() {

 ........

startOtherServices();

..........

}

private void startOtherServices() {

..............

//这部分代码在Android M上是没有的，但是Android N上有，所以就加在这了。

if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_FINGERPRINT)) {                                                                                                        
          mSystemServiceManager.startService(FingerprintService.class);
       }
............

}

这里调用SystemServiceManager的startService来启动指纹识别服务。

路径：

frameworks/base/services/core/java/com/android/server/SystemServiceManager.java

public <T extends SystemService> T startService(Class<T> serviceClass) {

..............

 try {                                   
            service.onStart();                  
         } catch (RuntimeException ex) {         
             throw new RuntimeException("Failed to start service " + name
                     + ": onStart threw an exception", ex);
         }                                       
         return service;                         

     }

在FingerprintService.java中调用了onStart()

路径：

frameworks/base/services/core/java/com/android/server/fingerprint/FingerprintService.java

public void onStart() {                                                                                                                                                                        
         publishBinderService(Context.FINGERPRINT_SERVICE, new FingerprintServiceWrapper());
         IFingerprintDaemon daemon = getFingerprintDaemon();
         if (DEBUG) Slog.v(TAG, "Fingerprint HAL id: " + mHalDeviceId);
         listenForUserSwitches();
     }

接下来，先看看publishBinderService的实现，

路径：

frameworks/base/services/core/java/com/android/server/SystemService.java

protected final void publishBinderService(String name, IBinder service) {
         publishBinderService(name, service, false);
     }

protected final void publishBinderService(String name, IBinder service,
            boolean allowIsolated) {
        ServiceManager.addService(name, service, allowIsolated);                                                                                                                                    
    }

可以看到在ServiceManager.java中调用了addService

路径：

frameworks/base/core/java/android/os/ServiceManager.java

 public static void addService(String name, IBinder service, boolean allowIsolated) {
        try {                  
             getIServiceManager().addService(name, service, allowIsolated);
         } catch (RemoteException e) {
            Log.e(TAG, "error in addService", e);
         }                      
    }

可以看到到这里真正的将指纹识别的服务加进去了，今天先到这，后面在继续。

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