【IVI】VehicleService启动

android12-release
Android Automotive OS知识体系

1、rc文件android.hardware.automotive.vehicle@2.0-service.rc

VehicleService进程名：vendor.vehicle-hal-2.0
bin文件：/vendor/bin/hw/android.hardware.automotive.vehicle@2.0-service
对应启动入口：hardware/interfaces/automotive/vehicle/2.0/default/VehicleService.cpp

hardware/interfaces/automotive/vehicle/2.0/default/android.hardware.automotive.vehicle@2.0-service.rc

service vendor.vehicle-hal-2.0 /vendor/bin/hw/android.hardware.automotive.vehicle@2.0-serviceclass haluser vehicle_networkgroup system inet

hardware/interfaces/automotive/vehicle/2.0/default/android.hardware.automotive.vehicle@2.0-service.xml

<manifest version="1.0" type="device"><hal format="hidl"><name>android.hardware.automotive.vehicle</name><transport>hwbinder</transport><version>2.0</version><interface><name>IVehicle</name><instance>default</instance></interface></hal>
</manifest>

2、VehicleService.cpp#main()启动

EmulatedVehicleConnector继承VehicleHalClient、VehicleHalServer（即是IVehicleServer、IVehicleClient）
hal = std::make_unique<impl::EmulatedVehicleHal>(store.get(), connector.get(), userHal)与VehicleHal通行，EmulatedVehicleHal最终继承VehicleHal
configureRpcThreadpool、joinRpcThreadpool 组队出现的东西，libhidl 库，用于自动生成HIDL语言，并辅助服务添加到 hwbinder域
VehicleHalManager 继承IVehicle ，再查看service->registerAsService()注册到 /dev/hwbinder 并添加到 defaultServiceManager()

int main(int /* argc */, char* /* argv */ []) {auto store = std::make_unique<VehiclePropertyStore>();auto connector = std::make_unique<impl::EmulatedVehicleConnector>();auto userHal = connector->getEmulatedUserHal();auto hal = std::make_unique<impl::EmulatedVehicleHal>(store.get(), connector.get(), userHal);auto emulator = std::make_unique<impl::VehicleEmulator>(hal.get());auto service = std::make_unique<VehicleHalManager>(hal.get());connector->setValuePool(hal->getValuePool());configureRpcThreadpool(4, true /* callerWillJoin */);ALOGI("Registering as service...");status_t status = service->registerAsService();if (status != OK) {ALOGE("Unable to register vehicle service (%d)", status);return 1;}ALOGI("Ready");joinRpcThreadpool();return 1;
}

2.1 libhidl、libhwbinder路径

Binder 域
system/libhidl/transport/HidlTransportSupport.cpp
system/libhidl/transport/include/hidl/HidlTransportSupport.h
system/libhidl/transport/ServiceManagement.cpp
system/libhidl/transport/include/hidl/ServiceManagement.h

system/libhwbinder/ProcessState.cpp
system/libhwbinder/IPCThreadState.cpp

2.2 hidl-gen自动生成代码文件Bp、Bn端：types.hal、IVehicle.hal、IVehicleCallback.hal

参考：

// This file is autogenerated by hidl-gen -Landroidbp.package {// See: http://go/android-license-faq// A large-scale-change added 'default_applicable_licenses' to import// all of the 'license_kinds' from "hardware_interfaces_license"// to get the below license kinds://   SPDX-license-identifier-Apache-2.0default_applicable_licenses: ["hardware_interfaces_license"],
}hidl_interface {name: "android.hardware.automotive.vehicle@2.0",root: "android.hardware",srcs: ["types.hal","IVehicle.hal","IVehicleCallback.hal",],interfaces: ["android.hidl.base@1.0",],gen_java: true,
}

3、时序图

4. 上层调用

packages/services/Car/service/src/com/android/car/CarService.java

private static IVehicle getVehicle() {final String instanceName = SystemProperties.get("ro.vehicle.hal", "default");try {return android.hardware.automotive.vehicle.V2_0.IVehicle.getService(instanceName);} catch (RemoteException e) {Slog.e(CarLog.TAG_SERVICE, "Failed to get IVehicle/" + instanceName + " service", e);} catch (NoSuchElementException e) {Slog.e(CarLog.TAG_SERVICE, "IVehicle/" + instanceName + " service not registered yet");}return null;
}