【IVI】VehicleService启动

【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-service
    class hal
    user vehicle_network
    group 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.vehiclename>
        <transport>hwbindertransport>
        <version>2.0version>
        <interface>
            <name>IVehiclename>
            <instance>defaultinstance>
        interface>
    hal>
manifest>

2、VehicleService.cpp#main()启动

• EmulatedVehicleConnector继承VehicleHalClient、VehicleHalServer（即是IVehicleServer、IVehicleClient）
• hal = std::make_unique(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-2.0
    default_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;
}