介绍USB服务在Android服务体系中的位置，源码的位置及使用AndroidStudio 查看USB模块FWK的配置方式。

Windows环境准备

WSL2安装及AOSP源码下载编译 (shimo.im)

安卓服务概览

Android 主要有如下7类服务：

1. 核心服务，如ActivityManagerService，WindowManagerService
2. 通信相关服务，如：Wifi相关服务，Telephone相关服务；
3. 系统功能相关服务，如：AudioService，MountService，UsbService；
4. BatteryService，VibratorService
5. 相对独立的服务：EntropyService,DiskStatsService,Watchdog;
6. 蓝牙服务
7. UI相关服务，如：状态栏服务，通知管理服务。

源码分布

• FWK/API 即 Java层api：
  • frameworks/base/core/java/android/hardware/usb/
  • frameworks/base/core/java/com/android/internal/usb
• Service 层： Java 及JNI实现
  • frameworks/base/services/usb (Java)
  • frameworks/base/services/core/jni/ (cpp)
  • system/core/libusbhost ©
• HAL（硬件抽象层） 接口定义 ：
  • hardware/interfaces/usb
• 内核层：
  • bionic/libc/kernel/uapi/linux/usb

阅读工具准备

AS项目文件生成

过滤规则编辑，在aosp源码根目录下添加名为 excluded-paths 的文件

# 几个根目录的规则
^art/.*
^packages/.*
^bootable/.*
^build/.*
^cts/.*
^dalvik/.*
^developers/.*
^external/.*
^platform_testing/.*
^pdk/.*
^sdk/.*
^system/.*
^test/.*
# platform-compat中有注解的类
^tools/(?!(platform-compat))
^development/.*
^device/.*
^prebuilts/*
# 这里我们查看这两个模块，所以注释掉
#^libcore/.*
#^frameworks/.*

# 关于out其他的一些规则
#^out/*
^out/soong/.intermediates/.*/stubsDir/.*
^out/soong/.intermediates/.*/aapt2/.*

#^out/soong/.intermediates/frameworks/base/system-api-stubs-docs/android_common/stubsDir/android/hardware/usb/UsbDevice.java
^out/soong/.intermediates/(?!((frameworks)|(libcore)))

# ./out/soong/.intermediates/frameworks/native/libs/binder/libbinder/android_x86_64_shared/gen/aidl/android/os/BnServiceManager.h
# ^out/soong/.intermediates/.*
#^out/target/.*

# 根据实际运行情况补充的规则
# 移除可能的jar
# 如 ./frameworks/base/tools/aapt2/integration-tests/CommandTests/android-28.jar
^frameworks/(?!base)
^frameworks/base/tools/aapt2/.*\.jar
# 排除一干测试文件目录
^frameworks/.*/tests
^frameworks/base/(?!((core)|(services)))
^hardware/interfaces/(?!usb)
^bionic/libc/kernel/uapi/linux/(?!usb)
^libcore/*
gradle-wrapper.jar
^tools/*

# 对于sdk源码的隐藏，我们exclude掉，以使可以找到真正的源码
^libcore/ojluni/annotations

执行如下命令生成 android.ipr 文件以供 AndroidStudio 使用：

# 在源码根目录执行
source build/envsetup.sh
# 加载正确的Java
lunch aosp_x86_64-eng 
cd development/tools/idegen
mm 

croot 
development/tools/idegen/idegen.sh

AS 配置

大小写敏感配置

idea.case.sensitive.fs=true

VM 配置

Android Studio 打开项目

打开之后需要一定时间建立索引。

vscode 打开项目

我们使用vscode 查看c/c++代码，字节在ubuntu中使用命令行打开对应目录即可，vscode会自动提示安装对应的本地及远程的c++插件，按提示安装即可。

code frameworks/base/services/core/jni/

配置 C++ 的头文件查找地址：

在包含路径中输入：aosp/** (如： /home/hanlyjiang/aosp/**）

参考

• Android8.0 USB系统框架_Sherlock的博客-CSDN博客_android usb框架
• PTP 和 MTP_Cxiaolinxiaozi的专栏-CSDN博客

附

find . -type d -name "usb"
./bionic/libc/kernel/uapi/linux/usb
./cts/apps/CtsVerifier/src/com/android/cts/verifier/usb
./cts/hostsidetests/usb
./cts/hostsidetests/usb/SerialTestApp/src/com/android/cts/usb
./cts/hostsidetests/usb/src/com/android/cts/usb
./cts/tests/tests/usb
./cts/tests/tests/usb/src/android/usb
./development/host/windows/prebuilt/usb
./development/host/windows/usb
./device/google/bonito/usb
./device/google/bramble/usb
./device/google/coral/usb
./device/google/crosshatch/usb
./device/google/redfin/usb
./device/google/sunfish/usb
./external/autotest/client/common_lib/cros/cfm/usb
./external/crosvm/devices/src/usb
./external/kernel-headers/original/uapi/linux/usb
./external/linux-kselftest/tools/testing/selftests/drivers/usb
./external/ltp/testcases/kernel/device-drivers/usb
./external/u-boot/doc/device-tree-bindings/usb
./external/u-boot/drivers/usb
./external/u-boot/include/dt-bindings/usb
./external/u-boot/include/linux/usb
./external/u-boot/include/usb
./frameworks/base/core/java/android/hardware/usb
./frameworks/base/core/java/com/android/internal/usb
./frameworks/base/libs/usb
./frameworks/base/libs/usb/src/com/android/future/usb
./frameworks/base/libs/usb/tests/AccessoryChat/accessorychat/linux/usb
./frameworks/base/packages/SystemUI/src/com/android/systemui/usb
./frameworks/base/services/usb
./frameworks/base/services/usb/java/com/android/server/usb
./frameworks/base/tests/UsbHostExternalManagmentTest/AoapTestDevice/src/com/android/hardware/usb
./frameworks/base/tests/UsbHostExternalManagmentTest/AoapTestHost/src/com/android/hardware/usb
./frameworks/base/tests/UsbHostExternalManagmentTest/UsbHostExternalManagmentTestApp/src/com/android/hardware/usb
./frameworks/base/tests/UsbTests/src/com/android/server/usb
./hardware/google/pixel/usb
./hardware/interfaces/usb
./packages/apps/Settings/src/com/android/settings/connecteddevice/usb
./packages/apps/Settings/tests/robotests/src/com/android/settings/connecteddevice/usb
./packages/services/Car/car-usb-handler/src/android/car/usb
./packages/services/Car/tests/CarDeveloperOptions/src/com/android/car/developeroptions/connecteddevice/usb
./packages/services/Car/tests/usb
./packages/services/Car/tests/usb/AoapHostApp/src/com/google/android/car/usb
./packages/services/Car/tests/usb/AoapPhoneCompanionApp/src/com/google/android/car/usb
./prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.17-4.8/sysroot/usr/include/linux/usb
./test/framework/harnesses/host_controller/utils/usb
./test/vts-testcase/fuzz/config/usb
./test/vts-testcase/hal/usb
./test/vts-testcase/hal/usb/gadget/V1_1/host/src/com/android/usb
./test/vts-testcase/hal-trace/usb
./tools/test/connectivity/acts/tests/google/usb

相关文件：

./hardware/interfaces/usb
./bionic/libc/kernel/uapi/linux/usb

./frameworks/base/services/usb
./frameworks/base/libs/usb

./frameworks/base/core/java/android/hardware/usb
./frameworks/base/core/java/com/android/internal/usb

./frameworks/base/services/core/jni/
com_android_server_UsbAlsaJackDetector.cpp
com_android_server_UsbDescriptorParser.cpp
com_android_server_UsbDeviceManager.cpp
com_android_server_UsbHostManager.cpp
com_android_server_UsbMidiDevice.cpp