MediaServer初始化时主要是和binder挂上钩。

android\frameworks\av\media\mediaserver\main_mediaserver.cpp

int main(int argc __unused, char** argv){               // all other services        sp<ProcessState> proc(ProcessState::self());        sp<IServiceManager> sm = defaultServiceManager();        ALOGI("ServiceManager: %p", sm.get());        AudioFlinger::instantiate();        MediaPlayerService::instantiate();        CameraService::instantiate();        AudioPolicyService::instantiate();        SoundTriggerHwService::instantiate();        registerExtensions();        ProcessState::self()->startThreadPool();        IPCThreadState::self()->joinThreadPool();    }