Android P HAL层添加HIDL实例

本文是参照 https://www.jianshu.com/p/b80865c61d8e 教程介绍实现，原理请参考原作者。

本文将介绍如何在P OS上添加HIDL详细实现过程，简单增加seLinux策略使得可以在system_service调用测试，并用模拟器emulator验证。

调用过程为 APP->TestManager->TestService->ITest.hal

文章目录

Android P HAL层添加HIDL实例
- 实现过程
- - 一、hardware部分
  - - 1.1 编写 .hal
    - 1.2 使用hidl-gen生成变量
    - 1.3 实现.cpp
    - - Test.h (由hidl-gen工具生成）
      - Test.cpp (由hidl-gen工具生成）
      - 添加启动service
    - 1.4 VNDK相关
  - 二、device部分
  - 三、SELinux部分——hal service
  - - 3.1 vendor 目录
    - 3.2 public 目录
    - 3.3 private 目录
  - 四、客户端实现
  - - 4.1 system_service 实现
    - - 4.1.1 TestManager端
      - 4.1.2 TestService端
      - 4.1.3 添加selinux策略
      - public 目录
        
        private 目录
    - 4.2 APP实现调用
    - - 4.2.1 APP调用TestManager
      - 4.2.2编写make文件
  - 五、启动模拟器验证
  - - 5.1 替换镜像文件到SDK下
    - 5.2 启动emulator
    - 5.3 ADB调试
- 附录——错误处理

实现过程

一、hardware部分

1.1 编写 .hal

.hal的语言格式是C++和Java的结合体。

在 AOSP代码目录 hardware/interfaces/test/1.0/

新建 types.hal (非必要，用于定义结构体，复杂变量可在此定义)

//types.hal
package android.hardware.test@1.0;struct TestID{int32_t id;string name;
};struct TestEvent{int32_t what;string msg;
};

新建ITestCallback.hal (非必要，用于回调使用)

//ITestCallback.hal
package android.hardware.test@1.0;interface ITestCallback {oneway onTestEvent(TestEvent event);
};

新建 ITest.hal (主接口)

//ITest.hal
package android.hardware.test@1.0;interface ITest {init(TestID id);//无返回值helloWorld(string name) generates (string result);//变量类型string 不是StringsetCallback(ITestCallback callback) generates (bool res);//变量类型bool 不是booleanrelease();
};

1.2 使用hidl-gen生成变量

使用hidl-gen的前提是AOSP全编通过，如果之前全编通过可不用再次全编

source ./build/envsetup.sh
lunch aosp_car_x86_64-eng
make -j4
make hidl-gen -j4

设置临时变量

PACKAGE=android.hardware.test@1.0
LOC=hardware/interfaces/test/1.0/default

使用hidl-gen生成default目录里的C++文件

hidl-gen -o $LOC -Lc++-impl -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport $PACKAGE

使用hidl-gen生成default目录里的Android.bp文件

hidl-gen -o $LOC -Landroidbp-impl -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport $PACKAGE

使用update-makefiles.sh生成1.0目录下的Android.bp

./hardware/interfaces/update-makefiles.sh

在default目录创建

此时的目录结构为

├── 1.0
│   ├── default
│   │   ├── Android.bp
│   │   ├── Test.cpp
│   │   ├── Test.h
│   │   ├── TestCallback.cpp
│   │   └── TestCallback.h
│   ├── Android.bp
│   ├── ITest.hal
│   ├── ITestCallback.hal
│   └── types.hal

TestCallback.cpp和 TestCallback.h没用删掉，并修改default里的Android.bp 删掉TestCallback.cpp

1.3 实现.cpp

Test.h (由hidl-gen工具生成）

line 35 注释打开就是使用passthrough模式

#ifndef ANDROID_HARDWARE_TEST_V1_0_TEST_H
#define ANDROID_HARDWARE_TEST_V1_0_TEST_H#include <android/hardware/test/1.0/ITest.h>
#include <hidl/MQDescriptor.h>
#include <hidl/Status.h>
#include <utils/Thread.h>namespace android {
namespace hardware {
namespace test {
namespace V1_0 {
namespace implementation {using ::android::hardware::hidl_array;
using ::android::hardware::hidl_memory;
using ::android::hardware::hidl_string;
using ::android::hardware::hidl_vec;
using ::android::hardware::Return;
using ::android::hardware::Void;
using ::android::sp;struct Test : public ITest , public Thread{// Methods from ::android::hardware::test::V1_0::ITest follow.Return<void> init(const ::android::hardware::test::V1_0::TestID& id) override;Return<void> helloWorld(const hidl_string& name, helloWorld_cb _hidl_cb) override;Return<bool> setCallback(const sp<::android::hardware::test::V1_0::ITestCallback>& callback) override;Return<void> release() override;// Methods from ::android::hidl::base::V1_0::IBase follow.virtual bool threadLoop();
};// FIXME: most likely delete, this is only for passthrough implementations
// extern "C" ITest* HIDL_FETCH_ITest(const char* name);}  // namespace implementation
}  // namespace V1_0
}  // namespace test
}  // namespace hardware
}  // namespace android#endif  // ANDROID_HARDWARE_TEST_V1_0_TEST_H

Test.cpp (由hidl-gen工具生成）

简单实现各个方法

#define LOG_TAG "Test_cpp"
#include "Test.h"
#include <log/log.h>namespace android {
namespace hardware {
namespace test {
namespace V1_0 {
namespace implementation {pthread_t pthread;
sp<ITestCallback> mCallback = nullptr;
std::string mName;
int32_t mID;
bool mExit;// Methods from ::android::hardware::test::V1_0::ITest follow.
Return<void> Test::init(const ::android::hardware::test::V1_0::TestID& id) {mExit = false;mName = id.name;mID = id.id;ALOGD("init:");run("test_thread");return Void();
}Return<void> Test::helloWorld(const hidl_string& name, helloWorld_cb _hidl_cb) {ALOGD("helloWorld:");char buf[100];::memset(buf,0x00,100);::snprintf(buf,100,"Hello World,%s",name.c_str());hidl_string result(buf);_hidl_cb(result);return Void();
}Return<bool> Test::setCallback(const sp<::android::hardware::test::V1_0::ITestCallback>& callback) {mCallback = callback;bool res = false;if(mCallback != nullptr) {ALOGD("setCallback: done");res = true;}return res;
}Return<void> Test::release() {mExit = true;ALOGD("release:");return Void();
}bool Test::threadLoop(){static int32_t count = 0;TestEvent event;while(!mExit) {::sleep(1);event.msg = mName;event.what = count ++;if(mCallback != nullptr) {mCallback->onTestEvent(event);}}ALOGD("threadLoop: exit");return false;
}// Methods from ::android::hidl::base::V1_0::IBase follow.//ITest* HIDL_FETCH_ITest(const char* /* name */) {//return new Test();
//}
//
}  // namespace implementation
}  // namespace V1_0
}  // namespace test
}  // namespace hardware
}  // namespace android

添加启动service

新建android.hardware.test@1.0-service.rc 启动脚本

service test_hal_service /vendor/bin/hw/android.hardware.test@1.0-serviceclass haluser systemgroup system

新建service.cpp 这里使用绑定式直通式为注释部分

#define LOG_TAG "android.hardware.test@1.0-service"
#include <android-base/logging.h>
#include <hidl/HidlTransportSupport.h>
#include <android/hardware/test/1.0/ITest.h>#include <hidl/LegacySupport.h>
#include "Test.h"
using android::hardware::configureRpcThreadpool;
using android::hardware::joinRpcThreadpool;
using android::hardware::test::V1_0::implementation::Test;
//using android::hardware::defaultPassthroughServiceImplementation;
//passthrough modeint main() {configureRpcThreadpool(4, true);Test test;auto status = test.registerAsService();CHECK_EQ(status, android::OK) << "Failed to register test HAL implementation";joinRpcThreadpool();return 0;  // joinRpcThreadpool shouldn't exit//   return defaultPassthroughServiceImplementation<ITest>();//passthrough mode
}

修改Android.bp

cc_binary {name: "android.hardware.test@1.0-service",relative_install_path: "hw",defaults: ["hidl_defaults"],proprietary: true,init_rc: ["android.hardware.test@1.0-service.rc"],srcs: ["Test.cpp","service.cpp",],shared_libs: ["libbase",      "liblog","libdl","libutils","libhardware","libhidlbase","libhidltransport","android.hardware.test@1.0",],
}

调用 update-makefiles.sh更新一下

当前目录结构为

├── 1.0
│   ├── default
│   │   ├── Android.bp
│   │   ├── Test.cpp
│   │   ├── Test.h
│   │   ├── android.hardware.test@1.0-service.rc
│   │   └── service.cpp
│   ├── Android.bp
│   ├── ITest.hal
│   ├── ITestCallback.hal
│   └── types.hal

单编试一下，出错请检查代码请参考附录解决办法。

mmm ./hardware/interfaces/test/1.0

1.4 VNDK相关

在目录aosp\build\make\target\product\vndk 里

28.txt 和 current.txt 按照字母顺序新增

VNDK-core: android.hardware.test@1.0.so

二、device部分

由于此次要使用emulator验证，并且lunch的是aosp_car_x86_64-eng

所以在device找到下面目录aosp\device\generic\car\common\manifest.xml

其他device要在对应的目录找到manifest

在manifest.xml添加

 <hal format="hidl"><name>android.hardware.test</name><transport>hwbinder</transport><version>1.0</version><interface><name>ITest</name><instance>default</instance></interface></hal>

在car.mk添加启动 test service

# Auto modules
PRODUCT_PACKAGES += \……android.hardware.test@1.0-service

三、SELinux部分——hal service

根据其他博主的文章搜集了一些SELinux的知识点进行补充：
对应sepolicy, Google 也设定了不同的存放目录, 以便进行分离, 以Google 默认的sepolicy 为例. /system/sepolicy

public: android 和 vendor 共享的sepolicy 定义, 通常情况下, 意味着vendor 开发者可能为此新增一些权限. 一般system/vendor 共用的一些类型和属性的定义, neverallow 限制等会存放于此.

private: 通常意义上的仅限于system image 内部的使用, 不对vendor 开放. 这个只会编译到system image 中.

vendor: 它仅仅能引用public 目录下的相关定义, 这个只会编译到vendor image 中. 但它依旧可以对system image 里面的module 设定sepolicy(对应module 需要在public 下进行声明); 在很大程度上绕过了Google GTS 约束测试.

mapping: 为兼容老版本的sepolicy 而导入, 只有在system image version > vendor version 的时候, 才可能被用到. 即包括两方面, 新版本增加的type , 新版本移除的type, 以及老版本public, 新版本private 等变化的设定, 以兼容老版本.

9.0上Android 安全策略再次加强，hal service需要修改selinux配置

lunch为 aosp_car_x86_64-eng 对应的car device目录下没有BoardConfig.mk，也没有对应的sepolicy

所以只能修改系统的sepolicy

目录为aosp\system\sepolicy

该目录下有vendor public private(注意public 下的修改同样也要修改到prebuilts\api\28.0 下的对应文件，否则编译会报错) 位置找不到参考audiocontrol的位置或者比较熟悉的hal模块

3.1 vendor 目录

file_contexts 添加

/(vendor|system/vendor)/bin/hw/android\.hardware\.test@1\.0-service          u:object_r:hal_test_default_exec:s0
#file_contexts文件保存系统中所有文件的安全上下文定义，每行前半部分是文件的路径，后面是它的安全上下文的定义(hal_test_default_exec)

新建 hal_test_default.te
在TE中，所有的东西都被抽象成类型。进程，抽象成类型；资源，抽象成类型。属性，是类型的集合。所以，TE规则中的最小单位就是类型。

#定义一个名字为 hal_test_default 的type
#TYPE是定义主体和客体所属的类型，对于进程而言，它的类型也称为domian。
#通常主体的type具有domian属性，因此，我们也把主体的type称为domain，将domain设置为hal_test_default的属性，表明zygote是用来描述进程的安全上下文的。

# Set a new domain called hal_test_default
type hal_test_default, domain;
# Set your domain as server domain of hal_xxx in which define by AOSP already
hal_server_domain(hal_test_default, hal_test)# Set your exec file type
type hal_test_default_exec, exec_type, vendor_file_type, file_type;
# Setup for domain transition
init_daemon_domain(hal_test_default)

3.2 public 目录

attributes 添加

hal_attribute(test);

hwservice.te 添加

type hal_test_hwservice, hwservice_manager_type;

新建 hal_test.te

# HwBinder IPC from client to server, and callbacks
binder_call(hal_test_client, hal_test_server)
binder_call(hal_test_server, hal_test_client)add_hwservice(hal_test_server, hal_test_hwservice)allow hal_test_client hal_test_hwservice:hwservice_manager find;

将以上修改同步到aosp\system\sepolicy\prebuilts\api\28.0\public

3.3 private 目录

hwservice_contexts 添加

android.hardware.test::ITest                                    u:object_r:hal_test_hwservice:s0

private/compat/26.0/26.0.ignore.cil 添加

hal_test_hwservice

private/compat/27.0/27.0.ignore.cil 添加

hal_test_hwservice

将以上修改同步到aosp\system\sepolicy\prebuilts\api\28.0\private

四、客户端实现

4.1 system_service 实现

4.1.1 TestManager端

在目录aosp\frameworks\base\core\java\android\os里新建test目录

创建ITestService.aidl 对应hal层四个功能

// ITestManager.aidl
package android.os.test;import android.os.test.ITestEventListener;
// Declare any non-default types here with import statementsinterface ITestService {/*** Demonstrates some basic types that you can use as parameters* and return values in AIDL.*/void init(int id,String name);String helloWorld(String str);boolean setTestEventListener(ITestEventListener listener);void release();}

创建ITestEventListener.aidl ITestService.aidl 里传递的自定类

// ITestEventListener.aidl
package android.os.test;
import android.os.test.TestListenerEvent;
// Declare any non-default types here with import statementsinterface ITestEventListener {/*** Demonstrates some basic types that you can use as parameters* and return values in AIDL.*/void onEvent (inout TestListenerEvent event);
}

创建TestListenerEvent.aidl ITestEventListener.aidl 里传递的 event 类型变量

// TestListenerEvent.aidl
package android.os.test;// Declare any non-default types here with import statementsparcelable TestListenerEvent;

创建TestListerEvent.java

package android.os.test;import android.os.Parcel;
import android.os.Parcelable;/*** android.os.test.TestListenerEvent** @author GW00175635* @date 2019/7/11*/
public class TestListenerEvent implements Parcelable {private int what;private String msg;public TestListenerEvent(int what, String msg) {this.what = what;this.msg = msg;}public TestListenerEvent(Parcel in) {what = in.readInt();msg = in.readString();}public void setWhat(int what) {this.what = what;}public void setMsg(String msg) {this.msg = msg;}public int getWhat() {return what;}public String getMsg() {return msg;}public static final Creator<TestListenerEvent> CREATOR = new Creator<TestListenerEvent>() {@Overridepublic TestListenerEvent createFromParcel(Parcel in) {return new TestListenerEvent(in);}@Overridepublic TestListenerEvent[] newArray(int size) {return new TestListenerEvent[size];}};@Overridepublic int describeContents() {return 0;}@Overridepublic void writeToParcel(Parcel dest, int flags) {dest.writeInt(what);dest.writeString(msg);}/*** <p>从parcel中读取，从parcel中读取，顺序与write一致</p>* 如果要支持为 out 或者 inout 的定向 tag 的话，需要实现 readFromParcel() 方法* @param dest*/public void readFromParcel(Parcel dest) {what = dest.readInt();msg = dest.readString();}}

创建TestManager.java 供上层APP调用的TestManager

package android.os.test;/*** android.os.test.TestManager;** @author GW00175635* @date 2019/7/11*/import android.os.RemoteException;
import android.util.Log;public class TestManager {private ITestService mService;public static final String TAG = "TestManager";public TestManager(ITestService server) {Log.d(TAG, "TestManager: ");mService = server;}public void init(int id,String name){Log.d(TAG, "init: "+id+" "+name);try {if (mService != null) {mService.init(id,name);}} catch (RemoteException e) {e.printStackTrace();}}public String helloWorld(String str) {Log.d(TAG, "helloWorld: "+str);try {if (mService == null) {return null;}return mService.helloWorld(str);} catch (RemoteException e) {e.printStackTrace();}return "service connect failed";}public boolean setTestListener(TestEventListener listener){Log.d(TAG, "setTestListener: ");try {if (mService == null) {return false;}return  mService.setTestEventListener(listener);} catch (RemoteException e) {e.printStackTrace();return false;}}public void release(){Log.d(TAG, "release: ");try {if(mService != null) {mService.release();}} catch (RemoteException e) {e.printStackTrace();}}
}

package android.os.test;/*** android.os.test**  GW00175635*  2019/7/13*/
public abstract class TestEventListener extends ITestEventListener.Stub  {}

在aosp\frameworks\base\Android.bp里添加

     "core/java/android/os/test/ITestEventListener.aidl","core/java/android/os/test/ITestService.aidl",

4.1.2 TestService端

在目录 aosp\frameworks\base\services\core

Android.bp添加test独有类的引用

    static_libs: [……"android.hardware.test-V1.0-java",……],

在目录 aosp\frameworks\base\services\core\java\com\android\server\test

新建TestService.java

package com.android.server.test;import android.hardware.test.V1_0.ITest;
import android.hardware.test.V1_0.ITestCallback;
import android.hardware.test.V1_0.TestEvent;
import android.hardware.test.V1_0.TestID;
import android.os.RemoteException;
import android.util.Log;import android.os.test.ITestEventListener;
import android.os.test.ITestService;
import android.os.test.TestListenerEvent;import java.util.ArrayList;/*** com.android.server.test.TestService** @author GW00175635* @date 2019/7/11*/
public class TestService extends ITestService.Stub {private String TAG = "TestService";private ITest halService ;public TestService(){try {halService = ITest.getService();//获取service} catch (RemoteException e) {e.printStackTrace();}}@Overridepublic void init(int id, String name) throws RemoteException {Log.d(TAG, "init: ");TestID testID = new TestID();testID.id = id;testID.name = name;halService.init(testID);}@Overridepublic String helloWorld(String str) throws RemoteException {Log.d(TAG, "helloWorld: ");return halService.helloWorld(str);}@Overridepublic boolean setTestEventListener(ITestEventListener listener) throws RemoteException {Log.d(TAG, "setTestEventListener: ");TestCallback testCallback = new TestCallback(listener);return halService.setCallback(testCallback);}@Overridepublic void release() throws RemoteException {Log.d(TAG, "release: ");halService.release();}class TestCallback extends ITestCallback.Stub{ITestEventListener mITestEventListener;TestCallback (ITestEventListener listener){mITestEventListener = listener;}@Overridepublic void onTestEvent(TestEvent testEvent) throws RemoteException {Log.d(TAG, "onTestEvent: ");TestListenerEvent testListenerEvent = new TestListenerEvent(testEvent.what,testEvent.msg);mITestEventListener.onEvent(testListenerEvent);}}}

在目录aosp\frameworks\base\core\java\android\content\Context.java里添加

 /*** {@link android.os.TestManager} for receiving intents at a* time of your choosing.** @see #getSystemService* @see android.os.TestManager*/public static final String TEST_SERVICE = "test";

在目录aosp\frameworks\base\core\java\android\app

SystemServiceRegistry.java 里添加

import android.os.test.TestManager;
import android.os.test.ITestService;……registerService(Context.TEST_SERVICE, TestManager.class,new CachedServiceFetcher<TestManager>() {@Overridepublic HelloManager createService(ContextImpl ctx) {IBinder iBinder = ServiceManager.getService(Context.TEST_SERVICE);if (iBinder == null) {return null;}ITestService service = ITestService.Stub.asInterface(iBinder);return new TestManager(service);}});……

在目录aosp\frameworks\base\services\java\com\android\server

SystemServer.java 添加

import com.android.server.test.TestService;private void startOtherServices(){……try {Slog.i(TAG, "test Service");ServiceManager.addService(Context.TEST_SERVICE, new TestService());} catch (Throwable e) {reportWtf("starting TestService", e);}……}

4.1.3 添加selinux策略

public 目录

service.te添加

type test_service, system_api_service, system_server_service, service_manager_type;

将以上修改同步到aosp\system\sepolicy\prebuilts\api\28.0\public

private 目录

service_contexts 添加和Context 保持一致 TEST_SERVICE = “test”;

test                                   u:object_r:test_service:s0

system_server.te 添加

hal_client_domain(system_server, hal_test)

private/compat/26.0/26.0.ignore.cil 添加

test_service

private/compat/27.0/27.0.ignore.cil 添加

test_service

将以上修改同步到aosp\system\sepolicy\prebuilts\api\28.0\private

4.2 APP实现调用

4.2.1 APP调用TestManager

在目录aosp\packages\apps\TestAPP下新建

res src 文件夹 src放代码 res放资源建议在Android studio里编写后复制相关文件到此目录

TestManager可以在Android studio里写个测试用的。

package com.gwm.testapp;import android.app.Activity;import android.content.Context;
import android.os.Bundle;
import android.os.RemoteException;
import android.os.test.TestManager;
import android.os.test.TestEventListener;
import android.os.test.TestListenerEvent;
import android.view.View;
import android.widget.Button;
import android.util.Log;/***  GW00175635*/
public class MainActivity extends Activity {TestManager mTestManager;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mTestManager = (TestManager)getSystemService(Context.TEST_SERVICE);Button init = findViewById(R.id.button_init);Button hello = findViewById(R.id.button_hello);Button set = findViewById(R.id.button_setCallback);Button release = findViewById(R.id.button_release);init.setOnClickListener(mOnClickListener);hello.setOnClickListener(mOnClickListener);set.setOnClickListener(mOnClickListener);release.setOnClickListener(mOnClickListener);}View.OnClickListener mOnClickListener = new View.OnClickListener() {@Overridepublic void onClick(View view) {switch (view.getId()){case R.id.button_init:mTestManager.init(123,"name=testAPP");break;case R.id.button_hello:String res = mTestManager.helloWorld("HelloFromTestAPP");Log.d("activity",res);break;case R.id.button_setCallback:mTestManager.setTestListener(new TestEventListener(){@Overridepublic void onEvent(TestListenerEvent event) {String msg = event.getMsg();int what = event.getWhat();Log.d("activity",msg+" "+what);}});break;case R.id.button_release:mTestManager.release();break;default:break;}}};}

4.2.2编写make文件

LOCAL_PATH := $(call my-dir)include $(CLEAR_VARS)
LOCAL_CERTIFICATE := platform
LOCAL_MODULE_TAGS := eng
LOCAL_PACKAGE_NAME := TestApp
LOCAL_SRC_FILES := $(call all-subdir-java-files)
LOCAL_PRIVATE_PLATFORM_APIS := true
include $(BUILD_PACKAGE)

最后代码目录为

五、启动模拟器验证

5.1 替换镜像文件到SDK下

因为改动了系统API，所以在全编之前执行 make update-api 更新下 API

再执行make 命令

全编之后，在产物目录aosp\out\target\product\generic_x86_64复制以下文件

替换到SDK目录C:\AndroidSDK\system-images\android-28\default\x86_64 里（如果没有该镜像目录，先在AVDManager里下载28 x86_64的镜像）

system-qemu.img 和 vendor-qemu.img 删掉qemu

复制产物目录的data文件夹到SDK目录替换

复制产物目录的system\build.prop 到SDK目录替换

在windows平台使用Android studio自带的AVDmanager 启动emulator。

5.2 启动emulator

选个分辨率差不多的

选择刚才替换的镜像

起一个好记的名字

使用AVDmanager启动

5.3 ADB调试

使用CMD命令

在SDK的emulator文件夹目录下

C:\AndroidSDK\emulator>emulator -avd Car0715 -writable-system

启动avd并让其system可写。

另起一个cmd命令框，就可以有写权限的使用ADB命令

附录——错误处理

1.语法错误，结构体少加分号 ;

root@BDJS-PF1LR28T:~/workspace/aosp# hidl-gen -o $LOC -Lc++-impl -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport $PACKAGE
ERROR: missing ; at /mnt/f/ubuntu_win/aosp/hardware/interfaces/test/1.0/types.hal:7.2-1
ERROR: missing ; at /mnt/f/ubuntu_win/aosp/hardware/interfaces/test/1.0/types.hal:12.2-1
hidl-gen F 07-10 11:01:06 30277 30277 Coordinator.cpp:213] Check failed: ret == nullptr
Aborted (core dumped)

2.语法错误，忘记import ITestCallbak

root@BDJS-PF1LR28T:~/workspace/aosp# hidl-gen -o $LOC -Lc++-impl -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport $PACKAGE
ERROR: Failed to lookup type 'ITestCallback' at /mnt/f/ubuntu_win/aosp/hardware/interfaces/test/1.0/ITest.hal:9.31-38
ERROR: Could not parse android.hardware.test@1.0::ITest. Aborting.

3.语法错误，boolean改成bool

root@BDJS-PF1LR28T:~/workspace/aosp# hidl-gen -o $LOC -Lc++-impl -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport $PACKAGE
ERROR: boolean is a Java keyword and is therefore not a valid identifier at /mnt/f/ubuntu_win/aosp/hardware/interfaces/test/1.0/ITest.hal:9.52-58
ERROR: Could not parse android.hardware.test@1.0::ITest. Aborting.

4.玄学bug 怀疑是没有make clean 导致的也可电脑配置太低如果之前能全编通过你也没有修改报错的目录，再次编译就好，然后可能就会发现这个错误没有了，会有新的错误，再次编译直到报错到你的目录或者编译通过，要每次都检查下TARGET_PRODUCT=aosp_car_x86_64 是不是之前你lunch的那个，有时候这个也会变。

PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=9
TARGET_PRODUCT=aosp_car_x86_64
TARGET_BUILD_VARIANT=eng
TARGET_BUILD_TYPE=release
TARGET_ARCH=x86_64
TARGET_ARCH_VARIANT=x86_64
TARGET_2ND_ARCH=x86
TARGET_2ND_ARCH_VARIANT=x86_64
HOST_ARCH=x86_64
HOST_2ND_ARCH=x86
HOST_OS=linux
HOST_OS_EXTRA=Linux-4.4.0-17134-Microsoft-x86_64-Ubuntu-16.04.5-LTS
HOST_CROSS_OS=windows
HOST_CROSS_ARCH=x86
HOST_CROSS_2ND_ARCH=x86_64
HOST_BUILD_TYPE=release
BUILD_ID=PPR1.180610.011
OUT_DIR=out[1/1] out/soong/.bootstrap/bin/soong_build out/soong/build.ninja
FAILED: out/soong/build.ninja
out/soong/.bootstrap/bin/soong_build -t -l out/.module_paths/Android.bp.list -b out/soong -n out -d out/soong/build.ninja.d -o out/soong/build.ninja Android.bp
error: external/llvm/tools/llvm-readobj/Android.bp:5:1: module "llvm-readobj" variant "linux_glibc_x86_64": module source path external/llvm/tools/llvm-readobj does not exist
ninja: build stopped: subcommand failed.
16:13:52 soong bootstrap failed with: exit status 1ninja: no work to do.
[1/1] out/soong/.bootstrap/bin/soong_build out/soong/build.ninja
FAILED: out/soong/build.ninja
out/soong/.bootstrap/bin/soong_build -t -l out/.module_paths/Android.bp.list -b out/soong -n out -d out/soong/build.ninja.d -o out/soong/build.ninja Android.bp
error: external/llvm/tools/llvm-readobj/Android.bp:5:1: module "llvm-readobj" variant "linux_glibc_x86_64": module source path external/llvm/tools/llvm-readobj does not exist
ninja: build stopped: subcommand failed.
16:13:52 soong bootstrap failed with: exit status 1ninja: no work to do.
[1/1] out/soong/.bootstrap/bin/soong_build out/soong/build.ninja
FAILED: out/soong/build.ninja
out/soong/.bootstrap/bin/soong_build -t -l out/.module_paths/Android.bp.list -b out/soong -n out -d out/soong/build.ninja.d -o out/soong/build.ninja Android.bp
error: external/ltp/gen.bp:10404:1: module "ltp_getpriority02" variant "android_x86_x86_64_core": module source path external/ltp/testcases/kernel/syscalls/getpriority/getpriority02.c does not exist
error: external/ltp/gen.bp:1517:1: module "ltp_uname02" variant "android_x86_x86_64_core": module source path external/ltp does not exist
error: external/ltp/gen.bp:1517:1: module "ltp_uname02" variant "android_x86_x86_64_core": module source path external/ltp/testcases/kernel/syscalls/uname/uname02.c does not exist
ninja: build stopped: subcommand failed.
16:16:32 soong bootstrap failed with: exit status 116:23:33 Could not create module-finder: finder encountered 1 errors: [/mnt/f/ubuntu_win/aosp/external/clang/test/Driver/Inputs/mips_cs_tree/lib/gcc/mips-linux-gnu/4.6.3/include-fixed/nan2008/el: lstat /mnt/f/ubuntu_win/aosp/external/clang/test/Driver/Inputs/mips_cs_tree/lib/gcc/mips-linux-gnu/4.6.3/include-fixed/nan2008/el: no such file or directory]

5.vndk相关

出现下面错误，删除aosp\out\target\product\generic_x86_64\obj\PACKAGING\vndk_intermediates里的libs.txt，保证aosp\build\make\target\product\vndk 里的28.txt current.txt相同注意要保持字母顺序添加

FAILED: out/target/product/generic_x86_64/obj/PACKAGING/vndk_intermediates/check-list-timestamp
/bin/bash -c "(( diff --old-line-format=\"Removed %L\"    --new-line-format=\"Added %L\"     --unchanged-line-format=\"\"    build/make/target/product/vndk/28.txt out/target/product/generic_x86_64/obj/PACKAGING/vndk_intermediates/libs.txt          || ( echo -e \" error: VNDK library list has been changed.\\n\" \"       Changing the VNDK library list is not allowed in API locked branches.\"; exit 1 )) ) && (mkdir -p out/target/product/generic_x86_64/obj/PACKAGING/vndk_intermediates/ ) && (touch out/target/product/generic_x86_64/obj/PACKAGING/vndk_intermediates/check-list-timestamp )"
Added VNDK-core: android.hardware.test@1.0.soerror: VNDK library list has been changed.Changing the VNDK library list is not allowed in API locked branches.

6.API相关更新下api make update-api

[ 21% 321/1522] Checking API:  checkpublicapi-current
FAILED: out/target/common/obj/PACKAGING/checkpublicapi-current-timestamp
/bin/bash -c "(( out/host/linux-x86/bin/apicheck -JXmx1024m -J\"classpath out/host/linux-x86/framework/doclava.jar:out/host/linux-x86/framework/jsilver.jar:prebuilts/jdk/jdk8/linux-x86/lib/tools.jar:)\"  -error 2 -error 3 -error 4 -error 5 -error 6 -error 7 -error 8 -error 9 -error 10 -error 11 -error 12 -error 13 -error 14 -error 15 -error 16 -error 17 -error 18 -error 19 -error 20 -error 21 -error 23 -error 24 -error 25 -error 26 -error 27  frameworks/base/api/current.txt  out/target/common/obj/PACKAGING/public_api.txt  frameworks/base/api/removed.txt  out/target/common/obj/PACKAGING/removed.txt || (  cat build/make/core/apicheck_msg_current.txt ; exit 38 ) ) ) && (mkdir -p out/target/common/obj/PACKAGING/ ) && (touch out/target/common/obj/PACKAGING/checkpublicapi-current-timestamp )"
out/target/common/obj/PACKAGING/public_api.txt:9538: error 5: Added public field android.content.Context.TEST_SERVICE
out/target/common/obj/PACKAGING/public_api.txt:33637: error 2: Added package android.os.test******************************
You have tried to change the API from what has been previously approved.To make these errors go away, you have two choices:1) You can add "@hide" javadoc comments to the methods, etc. listed in theerrors above.2) You can update current.txt by executing the following command:make update-apiTo submit the revised current.txt to the main Android repository,you will need approval.
******************************

7 AIDL 编译错误 Android.bp 里不需要添加aidl的自定义变量类如 parcelable TestListenerEvent;

Exception in thread "main" java.nio.file.NoSuchFileException: out/soong/.intermediates/frameworks/base/framework/android_common/gen/aidl/frameworks/base/core/java/android/os/test/TestListenerEvent.javaat java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:92)at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:116)at java.base/sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:215)at java.base/java.nio.file.Files.newByteChannel(Files.java:369)at java.base/java.nio.file.Files.newByteChannel(Files.java:415)at java.base/java.nio.file.Files.readAllBytes(Files.java:3207)at com.google.turbine.main.Main.parseAll(Main.java:105)at com.google.turbine.main.Main.compile(Main.java:69)at com.google.turbine.main.Main.compile(Main.java:61)at com.google.turbine.main.Main.main(Main.java:56)

8 资源文件找不到错误如果检查后不是自己的新添加的图片，直接再次全编。如果是自己的文件检查下是不是用了V7 V4的外部引用包资源主题背景等。

checkdir error:  cannot create out/target/common/obj/JAVA_LIBRARIES/android_system_stubs_current_intermediates/classes/resNo such file or directoryunable to process res/drawable-xhdpi-v4/btn_check_on_holo_dark.png.
checkdir error:  cannot create out/target/common/obj/JAVA_LIBRARIES/android_system_stubs_current_intermediates/classes/resNo such file or directoryunable to process res/drawable-xhdpi-v4/btn_check_on_holo_light.png.
checkdir error:  cannot create out/target/common/obj/JAVA_LIBRARIES/android_system_stubs_current_intermediates/classes/resNo such file or directoryunable to process res/drawable-xhdpi-v4/btn_check_on_pressed.png.
checkdir error:  cannot create out/target/common/obj/JAVA_LIBRARIES/android_system_stubs_current_intermediates/classes/resNo such file or directoryunable to process res/drawable-xhdpi-v4/btn_check_on_pressed_holo_dark.png.
checkdir error:  cannot create out/target/common/obj/JAVA_LIBRARIES/android_system_stubs_current_intermediates/classes/resNo such file or directoryunable to process res/drawable-xhdpi-v4/btn_check_on_pressed_holo_light.png.