Android添加硬件访问服务

2019-11-08 00:32:52

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添加硬件访问服务主要涉及三部分，JNI、AIDL、和Service。

JNI接口

在frameworks/base/services/core/jni/ 添加jni接口实现文件com_android_server_LedService.cpp。 com_android_server_LedService.cpp源文件:......static const JNINativeMethod methods[] = { {"native_ledOpen", "()I", (void *)ledOpen}, {"native_ledClose", "()V", (void *)ledClose}, {"native_ledCtrl", "(II)I", (void *)ledCtrl},};int register_android_server_LedService(JNIEnv *env){ return jniRegisterNativeMethods(env, "com/android/server/LedService", methods, NELEM(methods));}

2 修改frameworks/base/services/core/jni/onload.cpp

...namespace android { ... int register_android_server_Watchdog(JNIEnv* env);+int register_android_server_LedService(JNIEnv *env);};extern "C" jint JNI_OnLoad(javaVM* vm, void* reserved){ JNIEnv* env = NULL; jint result = -1; if (vm->GetEnv((void**) &env, JNI_VERSION_1_4) != JNI_OK) { ALOGE("GetEnv failed!"); return result; } ALOG_ASSERT(env, "Could not retrieve the env!"); register_android_server_PowerManagerService(env); +register_android_server_LedService(env); return JNI_VERSION_1_4;}

3 修改frameworks/base/services/core/jni/Android.mk

$(LOCAL_REL_DIR)/com_android_server_VibratorService.cpp /+ $(LOCAL_REL_DIR)/com_android_server_LedService.cpp /

AIDL

1.把 ILedService.aidl 放入 frameworks/base/core/java/android/os

package android.os;/** {@hide} */interface ILedService{ int ledCtrl(int which, int status);}修改 frameworks/base/Android.mk 添加一行 core/java/android/os/IVibratorService.aidl / +core/java/android/os/ILedService.aidl /

Service

1.添加新文件frameworks/base/services/java/com/android/server/SystemServer.java

package com.android.server;import android.os.ILedService;public class LedService extends ILedService.Stub { PRivate static final String TAG = "LedService"; /* call native c function to access hardware */ public int ledCtrl(int which, int status) throws android.os.RemoteException { return native_ledCtrl(which, status); } public LedService() { native_ledOpen(); } public static native int native_ledOpen(); public static native void native_ledClose(); public static native int native_ledCtrl(int which, int status);}

2.修改文件frameworks/base/services/java/com/android/server/SystemServer.java

+Slog.i(TAG, "Led Service"); +ServiceManager.addService("led", new LedService());