Android Automotive Framework调试技巧

adb shell
# netstat -ap |grep 7777
tcp        0      0 0.0.0.0:7777            0.0.0.0:*               LISTEN      2596/test_service
tcp        0      0 localhost:7777          localhost:45634         ESTABLISHED 2596/test_service
tcp6       0      0 localhost:45634         localhost:7777          ESTABLISHED 5336/com.android.test

subject= /C=CN/ST=NanJing/L=NanJing/O=13/OU=123/CN=123/emailAddress=test@123.com
issuer= /C=CN/ST=NanJing/L=NanJing/O=123/OU=13/CN=123/emailAddress=test@123.com

adb root;adb remount
adb shell
cd system
getprop | grep ro.build.tags

#可以看到一行 ro.build.tags=release-keys

# Start bootcharting as soon as possible after the data partition is
 # mounted to collect more data.
 mkdir /data/bootchart 0755 shell shell encryption=Require
 bootchart start
 ...
on property:sys.boot_completed=1
bootchart stop

#切横屏:
su
settings put system user_rotation 3
settings put system accelerometer_rotation 0
#切竖屏:
settings put system accelerometer_rotation  1/2/ 3 随便改

adb shell
# 同时适用于linux系统
df -ah
#或者
df -h

[core]
    editor=vim

~$ sudo dpkg-reconfigure dash
debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable

查询进程：
sudo lsof /var/cache/debconf/config.dat

杀进程：
sudo kill PID进程号

******************************************************
error: VNDK library: android.hardware.light@2.0's ABI has INCOMPATIBLE CHANGES Please check compatiblity report at : out/soong/.intermediates/hardware/interfaces/light/2.0/android.hardware.light@2.0/android_arm64_armv8-a_cortex-a53_vendor_shared/android.hardware.light@2.0.so.abidiff
******************************************************
 ---- Please update abi references by running platform/development/vndk/tools/header-checker/utils/create_reference_dumps.py -l android.hardware.light@2.0 ----

//执行该脚本后报错：
Traceback (most recent call last):
  File "development/vndk/tools/header-checker/utils/create_reference_dumps.py", line 224, in <module>
    main()
  File "development/vndk/tools/header-checker/utils/create_reference_dumps.py", line 210, in main
    targets = [Target(True, product), Target(False, product)]
  File "development/vndk/tools/header-checker/utils/create_reference_dumps.py", line 29, in __init__
    self.arch = build_vars[1]
IndexError: list index out of range

执行: ls -l /bin/sh，查看用的是什么来解释执行Python脚本

$ ls -l /bin/sh
lrwxrwxrwx 1 root root 4 4月   2  2019 /bin/sh -> dash

如果用dash来解释执行Python脚本，得切换成bash
执行： sudo dpkg-reconfigure dash  选择no

Android$ development/vndk/tools/header-checker/utils/create_reference_dumps.py -l android.hardware.light@2.0
Removing reference dumps...
removing /home/workspace/Android/prebuilts/abi-dumps/vndk/28/32/arm_armv7-a-neon/source-based/android.hardware.light@2.0.so.lsdump.gz
removing /home/workspace/Android/prebuilts/abi-dumps/ndk/28/32/arm_armv7-a-neon/source-based/android.hardware.light@2.0.so.lsdump.gz
making libs for product: aosp_arm_ab

//即自己编译的product name（out/target/product/test_product）
Android$ development/vndk/tools/header-checker/utils/create_reference_dumps.py -l android.hardware.light@2.0 -product test_product
Removing reference dumps...
removing /home//workspace/Android/prebuilts/abi-dumps/vndk/28/64/arm_armv8-a/source-based/android.hardware.light@2.0.so.lsdump.gz
removing /home//workspace/Android/prebuilts/abi-dumps/ndk/28/64/arm_armv8-a/source-based/android.hardware.light@2.0.so.lsdump.gz
removing /home//workspace/Android/prebuilts/abi-dumps/vndk/28/64/arm64_armv8-a/source-based/android.hardware.light@2.0.so.lsdump.gz
removing /home//workspace/Android/prebuilts/abi-dumps/ndk/28/64/arm64_armv8-a/source-based/android.hardware.light@2.0.so.lsdump.gz
making libs for product: test_product
Creating dumps for target_arch: arm and variant  armv8-a
Created abi dump at  /home//workspace/Android/prebuilts/abi-dumps/vndk/28/64/arm_armv8-a/source-based/android.hardware.light@2.0.so.lsdump.gz
Creating dumps for target_arch: arm64 and variant  armv8-a
Created abi dump at  /home//workspace/Android/prebuilts/abi-dumps/vndk/28/64/arm64_armv8-a/source-based/android.hardware.light@2.0.so.lsdump.gz

msg: Processed 2 libraries in  2.2664194742838544  minutes

# 项目代码根目录
adb root;adb remount
adb sync
adb shell sync
adb reboot

make plat_file_contexts -j9;
make plat_sepolicy.cil -j9;
make vendor_sepolicy.cil -j9;
make vendor_property_contexts -j9;

adb push out/target/product/product/vendor/etc/selinux/* vendor/etc/selinux/*
adb push out/target/product/product/system/etc/selinux/* system/etc/selinux/*

/out/target/common/obj/JAVA_LIBRARIES/android.car_intermediates$ ll
total 1988
drwxr-xr-x   2 user domain users   4096 Nov 26 16:34 ./
drwxr-xr-x 161 user domain users  12288 Nov 23 10:13 ../
-rw-r--r--   1 user domain users 578273 Nov 26 16:16 classes-header.jar
-rw-r--r--   1 user domain users 782057 Nov 26 16:16 classes.jar   ---------> 该文件作为app导入的jar包
-rw-r--r--   1 user domain users      0 Nov 12 11:24 exported-sdk-libs
-rw-r--r--   1 user domain users 648154 Nov 26 16:34 javalib.jar
-rw-r--r--   1 user domain users     14 Nov 12 11:24 link_type

$ cat ../../../payload_properties.txt 
#payload.bin升级包数据
FILE_HASH=Kw0egs8dY9Qm1sULkpkAPF+0PiKx14Uo0fHGZO3vNAk=
FILE_SIZE=2515281637
#压缩后的 manifest 数据
METADATA_HASH=z+5Qz8UIBrhCtMDgo+5IG4/rQqFUqmN/FMFyIWhaIEU=
METADATA_SIZE=179557

$ ls -l payload.bin 
#文件大小对应
-rw-r--r-- 1 user domain users 2515281637 Jan  1  2009 payload.bin
$ sha256sum payload.bin | awk '{print $1}' | xxd -r -ps | base64
#计算后的文件hash值对应
Kw0egs8dY9Qm1sULkpkAPF+0PiKx14Uo0fHGZO3vNAk=

#计算后的metadata hash值对应
$ dd if=payload.bin bs=1 count=179557 2>/dev/null | sha256sum | awk '{print $1}' | xxd -r -ps | base64 
z+5Qz8UIBrhCtMDgo+5IG4/rQqFUqmN/FMFyIWhaIEU=

sudo losetup -d /dev/loop0
sudo losetup -d /dev/loop1
sudo losetup -d /dev/loop2
sudo losetup -d /dev/loop3

/out/target/product/product/system$ find . -iname "*systemui*"
./product/priv-app/CarSystemUI
./product/priv-app/CarSystemUI/CarSystemUI.apk
./product/etc/permissions/com.android.systemui.xml

adb root
adb pull /data/misc/update_engine_log
adb pull /data/misc/update_engine/

adb shell
/data/misc/update_engine/prefs # ls -thl
total 38K
-rw------- 1 root root   1 2021-01-01 00:11 total-bytes-downloaded
-rw------- 1 root root  17 2021-01-01 00:11 system-updated-marker
-rw------- 1 root root   1 2021-01-01 00:11 delta-update-failures
-rw------- 1 root root  36 2021-01-01 00:11 update-completed-on-boot-id
-rw------- 1 root root   4 2021-01-01 00:11 post-install-succeeded
-rw------- 1 root root   4 2021-01-01 00:09 verity-written
-rw------- 1 root root   1 2021-01-01 00:08 update-state-next-data-length
-rw------- 1 root root   9 2021-01-01 00:08 update-state-next-data-offset
-rw------- 1 root root   4 2021-01-01 00:08 update-state-next-operation
-rw------- 1 root root 112 2021-01-01 00:08 update-state-sha-256-context
-rw------- 1 root root 264 2021-01-01 00:08 update-state-signature-blob
-rw------- 1 root root 112 2021-01-01 00:08 update-state-signed-sha-256-context
-rw------- 1 root root   6 2021-01-01 00:02 manifest-metadata-size
-rw------- 1 root root   3 2021-01-01 00:02 manifest-signature-size
-rw------- 1 root root   4 2021-01-01 00:02 dynamic-partition-metadata-updated
-rw------- 1 root root   1 2021-01-01 00:02 resumed-update-failures
-rw------- 1 root root  88 2021-01-01 00:02 update-check-response-hash
-rw------- 1 root root  36 1970-01-01 08:00 boot-id
-rw------- 1 root root  24 1970-01-01 08:00 previous-version
:/data/misc/update_engine/prefs # cat boot-id
e2ecfeb4-d097-449c-8c7b-e8aee5067cc6

:/data/misc/update_engine/prefs # cat previous-version
eng.user.20211201.031118

:/data/misc/update_engine/prefs # cat update-check-response-hash
LBhFc9jN99sOu9/VKy7COfkBXtXzlDt5fHdx1kQyU3c=vsNI/ZuKzDY0uOuXZIOjr42UHrzJ86isJSEtAwlFf9k=

//android/system/update_engine/common/error_code.h
// Action exit codes.
enum class ErrorCode : int {
  kSuccess = 0,   //升级成功
  kError = 1,  //升级失败
  kOmahaRequestError = 2, //请求action错误（action机制用于控制升级每个步骤）
  kOmahaResponseHandlerError = 3,   //返回handler action错误
  kFilesystemCopierError = 4,  //文件系统拷贝错误
  kPostinstallRunnerError = 5,   //预编译运行步骤错误（PostinstallRunner是一个升级步骤）
  kPayloadMismatchedType = 6,    //NOT NEED
  kInstallDeviceOpenError = 7, //安装设备打开错误
  kKernelDeviceOpenError = 8, //内核设备打开错误
  kDownloadTransferError = 9, //下载传输错误
  kPayloadHashMismatchError = 10, //升级包hash未匹配错误
  kPayloadSizeMismatchError = 11,   //升级包size未匹配错误
  kDownloadPayloadVerificationError = 12, //下载过程升级包校验错误
  kDownloadNewPartitionInfoError = 13, //下载过程新分区信息错误
  kDownloadWriteError = 14,   //下载过程数据写入错误
  kNewRootfsVerificationError = 15, //升级分区hash校验失败
  kNewKernelVerificationError = 16, //升级kernel校验失败
  kSignedDeltaPayloadExpectedError = 17,  //NOT NEED
  kDownloadPayloadPubKeyVerificationError = 18, //下载过程升级包public key公钥校验错误
  kPostinstallBootedFromFirmwareB = 19,   //NOT NEED
  kDownloadStateInitializationError = 20, //下载状态初始化错误
  kDownloadInvalidMetadataMagicString = 21, //NOT NEED
  kDownloadSignatureMissingInManifest = 22,  //下载过程manifest缺少签名错误
  kDownloadManifestParseError = 23, //下载过程manifest分析错误
  kDownloadMetadataSignatureError = 24,   //下载过程元数据签名错误
  kDownloadMetadataSignatureVerificationError = 25,   //下载过程元数据签名校验错误
  kDownloadMetadataSignatureMismatch = 26,   //下载过程元数据签名不匹配错误
  kDownloadOperationHashVerificationError = 27, //下载过程操作hash校验错误
  kDownloadOperationExecutionError = 28,  //下载过程操作执行错误
  kDownloadOperationHashMismatch = 29, //下载过程操作hash不匹配错误
  kOmahaRequestEmptyResponseError = 30,   //请求action无返回错误
  kOmahaRequestXMLParseError = 31,  //请求action分析xml错误
  kDownloadInvalidMetadataSize = 32,   //下载过程非法元数据大小
  kDownloadInvalidMetadataSignature = 33, //下载过程非法元数据签名
  kOmahaResponseInvalid = 34, //返回action非法错误
  kOmahaUpdateIgnoredPerPolicy = 35,   //NOT NEED（含义是接收已回滚版本，忽略此次升级）
  kOmahaUpdateDeferredPerPolicy = 36,  //NOT NEED（含义是因更新策略延迟，忽略此次升级）
  kOmahaErrorInHTTPResponse = 37,   //HTTP返回错误
  kDownloadOperationHashMissingError = 38,   //下载过程操作时缺失hash错误
  kDownloadMetadataSignatureMissingError = 39,  //下载过程元数据签名缺失错误
  kOmahaUpdateDeferredForBackoff = 40,    //NOT NEED（含义是忽略本次升级）
  kPostinstallPowerwashError = 41,  //NOT NEED（回滚报错，该版本已去除版本回滚限制）
  kUpdateCanceledByChannelChange = 42, //通道变化升级取消
  kPostinstallFirmwareRONotUpdatable = 43, //NOT NEED(需要升级固件firmware时才会取消，因为无法从FW B分区启动到FW A分区)
  kUnsupportedMajorPayloadVersion = 44, //获取manifest偏移量错误
  kUnsupportedMinorPayloadVersion = 45,   //未manifest可支持更小版本错误
  kOmahaRequestXMLHasEntityDecl = 46, //请求action xml hash非法错误
  kFilesystemVerifierError = 47, //文件系统校验错误（FilesystemVerifier是一个升级步骤）
  kUserCanceled = 48, //用户取消
  kNonCriticalUpdateInOOBE = 49, //NOT NEED（Ignoring a non-critical Omaha update before OOBE completion.）
  kOmahaUpdateIgnoredOverCellular = 50,   //NOT NEED（未设置设备策略，因此用户首选项需要覆盖是否允许通过蜂窝网络进行更新）
  kPayloadTimestampError = 51, //升级包时间戳错误 （payload.bin是OTA镜像打包文件）
  kUpdatedButNotActive = 52,  //升级分区非action状态错误
  kNoUpdate = 53, //无升级（There are no updates. Aborting.）
  kRollbackNotPossible = 54,  //NOT NEED
  kFirstActiveOmahaPingSentPersistenceError = 55,  //NOT NEED（用于旧设备的Omaha校验）
  kVerityCalculationError = 56,  //校验计算错误（在FilesystemVerifier步骤中进行分区校验时）

- art/  # Android runtime运行环境, java虚拟机art源码
- bionic/ # C库
- bootable/	# 启动引导和恢复系统相关代码（bootloader和recovery）
   - bootloader
      - dramk_2712/	
   	- lk/	 # liitle kernel，负责引导Linux的⼀个迷你⼩系统，启动顺序位于fastboot/uboot之后，Linux kernel之前，系统开机之后是进Android还是进recovery，即是这⾥负责
	   - lk_ext_mod/
   - recovery # 负责升级、恢复出⼚等⼀些⽐较重要⼜不是很复杂的⼯作，一般属于升级update子模块

- bootstrap.bash	
- build/	# 存放系统编译规则等基础开发包配置
   - blueprint # .bp的全程，由Go语⾔编写，是⽣成、解析Android.bp的⼯具，是Soong的⼀部分。Soong则是专为Android编译⽽设计的⼯具，Blueprint只是解析⽂件的形式，⽽Soong则解释内容的含义
   - kati # 基于Makefile来⽣成ninja.build的⼩项⽬。主要⽤于把Makefile转成成ninja file，⾃⾝没有编译能⼒，转换后使⽤Ninja编译
   - make
   - soong # Soong（go语言写的项目）构建系统是在Android 7中引⼊的，旨在取代Make。它利⽤Kati GNU Make克隆⼯具和Ninja构建系统组件来加速 Android 的构建；Soong在编译时使⽤，解析Android.bp，将之转化为Ninja⽂件

- compatibility/	# 兼容性计划文档目录，一些markdown文档
- cts/	# cts测试用例源码，但是一般cts跑测是从官网下载官方更新的cts测试包，如果跑测出现case faile，可以根据log在这边阅读源码分析
- dalvik/	# java dalvik虚拟机
- developers/	# demo源码和开发者参考文档
   - demo
   - samples
- development/	# 应用程序开发相关的实例/模板/工具
   - apps  # 开发者选项等app
   - tools

- device/	# 芯片厂商定制代码，包含AOSP自带的多家芯片厂以及芯片平台的代码，android O引入treble后，该目录下大部分关于厂商定制的源码移到vendor目录下
   - mediatek_projects # 此目录存放芯片平台平台下，几种不同的变种芯片项目编译定制化内容

- external/	# 开源第三方组件模块，存放着⼤量Google在创造、更新Android过程中，因实现某些功能⽽引⼊的开源第三⽅库，有些库是做了多系统适配（例如适配Android、Win、Linux），有些是only for Android
   - aac/ # aac解码库，AAC是高级音频编码（Advanced Audio Coding）
   - bsdiff/ # diff工具

- frameworks/	# framework层，应用程序框架层
   - av
      - camera # cameram模块
      - cmds 
         - screenrecord/	# 录屏工具源码
	      - stagefright/	   # 一个多媒体框架
      - media # audio、media源码
      - packages # 只有一个MediaComponents apk源码
      - services # audioflinger、cameraservice、mediacodec等核心源码
      - soundtrigger # audio模块的语音识别唤醒相关
   - base
      - api #Android对外暴露的API整体存放位置，make update-api命令更新的就是这里的文件
      - cmds # 命令/工具源码路径，例如am、pm、screencap等
         - bootanimation/	# 开机动画
      - core # android java和JNI核心库源码，例如framework.jar,hwbinder.jar,libandroid_runtime等
         - jni # libandroid_runtime
      - data # Android系统中字体、效果音等资源文件存放目录
      - graphics # graphic基础补充库，属于framework.jar
      - libs # display模块的hwui库位于这个目录下，以及其他的几个模块
      - media # media部分的java实现和jni实现源码，java部分属于framework.jar
      - opengl # opengl java api，隶属于framework.jar
      - packages # aosp core app源码路径，有DocumentsUI、Keyguard、MtpDocumentsProvider、SettingsProvide、SystemUI、Wallpaper等
      - services # service.jar源码，systemServer中启动的多数java service服务代码所在地
      - telecomm/	# tele模块，属于framework.jar
      - telephony/
      - wifi # wifi java api源码目录，属于framework.jar
   - native
      - cmds # bugreport、dumpsys等Android debug工具的c实现源码，以及serviceManager
      - libs # binder的Android中间件层实现源码，及libgui、libui、libsensor等中间件库源码
      - opengl # OpenGL的c/c++实现源码
      - services # 一些Android核心C进程的C/C++源码，例如surfaceFlinger、inputflinger、sensorservice等

- gerrit_config.sh
- hardware/	 # 硬件适配层hal层
   - interfaces/  # Android aosp定义的hidl interface实现，hal service实现源码
   - libhardware
      - moudles
         - audio
         - camera
         - input
   - mediatek  # 芯片平台 HAL实现代码，上层对接Google HIDL interface

- kernel/ # aosp的kernel适配目录
- kernel-4.9/	# kernel层源码，Android P之前使用，Q和R是4.14
- libcore/	# Java api核心库实现源码，dalvik、art部分java实现代码也在这里
   - dalvik
- libnativehelper/	# native层helper，即JNJ相关cpp源码
- Makefile	# 全局makefile
- packages/	# 大部分android apk源码
   - apps
      - Calendar #日历应用
      - Camera2/ # 官方camera
      - car
      - Email/
      - Gallery # 图库
      - SoundRecorder   # 录音机
   - providers # 存放着一堆provider的源码，media模块使用的MediaProvider，ContactsProvider等
   - services  # java service源码位置
      - car  # carservice源码

- pdk/	# platform development kit，平台开发工具
- platform_testing/	# 平台一些测试相关的源码
- prebuilts/	# 预编译资源
   - go # go语言环境，比如用于支持soong
- sdk/	# sdk工具源码
- system/	# 底层文件系统库、应用、组件，特殊功能模块
   - bt # 蓝牙相关
   - connectivity # wifi相关库
   - core # Android C/C++部分核心组件源码，有相当一部分是common类的组件
      - adb # adb进程源码
      - fastboot  # fastboot命令工具源码
      - healthd   # 电池服务守护进程源码
      - init      # init进程实现源码
      - libcutils # 工具库源码，例如property_set
      - ibion # ion内存管理工具类源码
      - liblog # ALOGX等相关函数实现源码
      - libusbhost # usbhost实现库
      - logcat # logcat实现源码
      - logd # 负责输出log的logd守护进程源码
      - sdcard # 外置存储卡挂载时会使用到的工具类
   - hwservicemanager   # hwservicemanager的实现源码，负责管理hidl service的，类似serviceManager
   - libhidl # hidl功能的c/c++层实现源码
   - libhwbinder # hwbinder功能的实现源码
   - sepolicy # aosp selinux配置文件所在目录
   - vold # 用于磁盘管理的守护进程

- test/	# vts测试源码
   - vts
- toolchain/ # Android工具链
- tools/	# android一些工具的源码，例如apk签名
   - apksig
- vendor/	# 厂商定制模块（芯片厂商以及我司定制化功能的实现代码）
   - mediatek  # 
      - external/	
	   - hardware/	
	   - kernel_modules/	
	   - packages/	# 芯片平台方案的私有app源码
      - proprietary/

1. root权限关闭，默认情况下⽆法adb root，⽆法adb remount，发货版本均为user版；
2. 仅标签为user的模块会参与编译；
3. app及jar包，及java源码的代码混淆被开启（除⾮显式指定关闭的模块会关闭）；
4. 不包含D级别log输出

1. root权限开启，可remount，开发常⽤版本；
2. 标签为user、userdebug的模块会参与编译

1. root权限开启；
2. 标签为user、userdebug、eng的模块参与编译

am_pss: Pid, UID, ProcessName, Pss, Uss
am_pss (Pid|1|5),(UID|1|5),(Process Name|3),(Pss|2|2),(Uss|2|2),(SwapPss|2|2),(Rss|2|2),(StatType|1|5),(ProcState|1|5),(TimeToCollect|2|2)

am_meminfo: Cached,Free,Zram,Kernel,Native
am_low_memory: NumProcesses

//内存含义
vss (virtual set size) 虚拟内存，从进程地址空间统计，包括未实际申请到物理内存的部分。
rss (resident set size) 实际物理内存+共享库。共享库如果映射多个进程，不均摊。
pss ( proportional set size) 物理内存+均摊的共享内存。
uss (unique set size) 独占物理内存，不包含共享库部分（进程所占用的私有内存（内存泄漏的最佳观察数据）不包含so库占用内存的）

//例如
Line 82266: 01-01 08:24:27.599  2697  2798 I am_pss  : [3541,1000,vendor.projection.androidauto,51497984,47623168,0,133905408,0,5,7]

Tasks: 227 total,   1 running, 226 sleeping,   0 stopped,   0 zombie
  Mem:      2.8G total,      2.1G used,      733M free,      4.0M buffers
 Swap:      1.4G total,       38M used,      1.3G free,      323M cached
400%cpu  42%user   0%nice 111%sys 233%idle   0%iow   8%irq   6%sirq   0%host
  PID USER         PR  NI VIRT  RES  SHR S[%CPU] %MEM     TIME+ ARGS
 4279 shell        20   0  35M 9.0M 2.4M R 55.5   0.3   0:00.15 top -d 3
 2316 system       -3 -20 165M  16M 5.0M S 27.7   0.5  17:25.76 android.hardware.graphics.composer@2.3-service
 2314 system       -2  -8 340M  30M  15M S 25.0   1.0  16:40.84 surfaceflinger

adb shell
# 如果该进程其值为0。0表示该进程是正在前台运行
cat proc/917/oom_adj

$ service list|grep Update
60      updatelock: [android.os.IUpdateLock]
61      system_update: [android.os.ISystemUpdateManager]
105     webviewupdate: [android.webkit.IWebViewUpdateService]
147     android.os.UpdateEngineService: []

symbols/vendor$ addr2line -f -e bin/test_service 000000000000ac40
_ZN12UpdateSocket9handleMsgEPv
vendor/..../test.cpp:87

ifeq ($(PRODUCT_MODEL),XXX_A)
LOCAL_CFLAGS += -DBUILD_MODEL
endif

#ifdef BUILD_MODEL
....
#endif

8|console:/dev/block/by-name # e2fsck -d vendor_a
e2fsck 1.44.4 (18-Aug-2018)
vendor: clean, 748/32768 files, 120659/131072 blocks
console:/dev/block/by-name #

console:/dev/block/by-name # e2fsck -a vendor_a
vendor: clean, 748/32768 files, 120659/131072 blocks
console:/dev/block/by-name #

console:/dev/block/by-name # e2fsck -c vendor_a
e2fsck 1.44.4 (18-Aug-2018)
sh: badblocks: inaccessible or not found
vendor: Updating bad block inode.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information

vendor: ***** FILE SYSTEM WAS MODIFIED *****
vendor: 748/32768 files (0.9% non-contiguous), 120659/131072 blocks

source ./build/envsetup.sh
lunch platform_name        ###(platform_name对应的sdk）
mmm external/e2fsprogs/misc/

//车机dd出来的img
Debug_OTA_0401_img$ file system_old.img 
system_old.img: Linux rev 1.0 ext4 filesystem data, UUID=4729639d-b5f2-5cc1-a120-9ac5f788683c (extents) (large files) (huge files)

//系统编译的img
$ file system.img 
system.img: Android sparse image, version: 1.0, Total of 1310720 4096-byte output blocks in 86 input chunks.

Debug_OTA_0401_img$ file system_old.img 
system_old.img: Linux rev 1.0 ext4 filesystem data, UUID=4729639d-b5f2-5cc1-a120-9ac5f788683c (needs journal recovery) (extents) (large files) (huge files)
Debug_OTA_0401_img$ mkdir 1
Debug_OTA_0401_img$ sudo mount system_old.img 1/ -o loop

system/core/libsparse/simg2img.c // 将sparse image转换为raw image;
system/core/libsparse/img2simg.c // 将raw image转换为sparse image;

$ .build/envsetup.sh
$ lunch aosp_hammerhead-userdebug
$ make img2simg_host

//车机dd出来的img
Debug_OTA_0401_img$ file system_old.img 
system_old.img: Linux rev 1.0 ext4 filesystem data, UUID=4729639d-b5f2-5cc1-a120-9ac5f788683c (extents) (large files) (huge files)

//系统编译的img
$ file system.img 
system.img: Android sparse image, version: 1.0, Total of 1310720 4096-byte output blocks in 86 input chunks.

Debug_OTA_0401_img$ file system_old.img 
system_old.img: Linux rev 1.0 ext4 filesystem data, UUID=4729639d-b5f2-5cc1-a120-9ac5f788683c (needs journal recovery) (extents) (large files) (huge files)
Debug_OTA_0401_img$ mkdir 1
Debug_OTA_0401_img$ sudo mount system_old.img 1/ -o loop

source build/envsetup.sh
make lpunpack

./lpdump super.img_raw(这里是用 simg2img 转换后的文件)

# 制作全量升级包
$ ./build/tools/releasetools/ota_from_target_files \
    dist-output/bcm7252ssffdr4-target_files-eng.ygu.zip \
    full-ota.zip

# 制作增量升级包
$./build/tools/releasetools/ota_from_target_files \
    -i dist-output/bcm7252ssffdr4-target_files-eng.ygu.zip \
    dist-output-new/bcm7252ssffdr4-target_files-eng.ygu.zip \
    incremental-ota.zip

/system/priv-app/CarSettings # dumpsys package|grep "car.settings"
        d1e0997 com.android.car.settings/.common.CarSettingActivity (2 filters)
        .....
/system/priv-app/CarSettings # dumpsys activity top|grep ACTIVITY
  ACTIVITY com.android.car.settings/.common.CarSettingActivity 154d0d8 pid=6296

/system/priv-app/CarSettings # am start com.android.car.settings/.common.CarSettingActivity
Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.android.car.settings/.common.CarSettingActivity }
Warning: Activity not started, intent has been delivered to currently running top-most instance.

.rc文件：
//服务定义：
service screencnap/system/bin/test_service
# class 包括core main late_start等，可以不设置。默认default
class main
# 用户属性，默认root，一般给root即可，权限最大
user root
# 所属组，默认root
group root
# disabled 即通过class不能启动，只能start screencap 这种name的方式启动
disabled
# 只运行一次
oneshot

//服务启动条件:
on property:sys.start_service=1
start test_service

//Android.mk
LOCAL_INIT_RC := test.rc

//因为该属性设成true表示vendor专属模块
//如果要移到vendor/bin，则注释掉proprietary : true

//Android.bp
init_rc: ["test.rc"],

# test service
PRODUCT_PACKAGES += \
    test_service

# test service
/vendor/bin/test_service u:object_r:test_service_exec:s0

# ls -al
total 36
drwxrwxrwx  4 system system  4096 2021-12-12 08:00 .
drwxr-xr-x 25 root   root    4096 2022-03-15 18:48 ..
drwx------  2 root   root   16384 1970-01-01 08:00 lost+found
drwx------  3 system system  4096 2021-12-12 08:00 usb

adb shell
/sdcard/Android/data # ls -lAZ
total 4
-rw-rw---- 1 root   sdcard_rw u:object_r:sdcardfs:s0    0 2021-01-01 08:00 .nomedia
drwxrwx--x 3 system sdcard_rw u:object_r:sdcardfs:s0 4096 2021-01-01 08:00 com.android.media

type=1400 audit(0.0:124): avc: denied { write } for name="com.engineeringmode-Ok7vxJdZR3gumPFFem-2fg==" dev="mmcblk0p43" ino=8777 scontext=u:r:system_app:s0 tcontext=u:object_r:apk_data_file:s0 tclass=dir permissive=0

01-01 08:03:22.410000   217   217 W applypatch: type=1400 audit(0.0:16): avc: denied { read } for name="mmcblk0p15" dev="tmpfs" ino=3364 scontext=u:r:install_recovery:s0 tcontext=u:object_r:block_device:s0 tclass=blk_file permissive=0

Line 43826: 01-01 09:44:32.220  5076  5076 W engineeringmode: type=1400 audit(0.0:540): avc: denied { search } for name="/" dev="mmcblk0p41" ino=2 scontext=u:r:system_app:s0 tcontext=u:object_r:unlabeled:s0 tclass=dir permissive=0
    Line 43826: 01-01 09:44:32.220  5076  5076 W engineeringmode: type=1400 audit(0.0:540): avc: denied { search } for name="/" dev="mmcblk0p41" ino=2 scontext=u:r:system_app:s0 tcontext=u:object_r:unlabeled:s0 tclass=dir permissive=0

/dev/block/by-name $ ls -al
...
lrwxrwxrwx 1 root root   21 1970-01-01 08:00 system -> /dev/block/mmcblk0p41

# 修改device/project/init.project.rc
 on fs
    restorecon_recursive /system

//system/sepolicy/README 
SYSTEM_EXT_PUBLIC_SEPOLICY_DIRS += device/acme/roadrunner-sepolicy/systemext/public
SYSTEM_EXT_PRIVATE_SEPOLICY_DIRS += device/acme/roadrunner-sepolicy/systemext/private
PRODUCT_PUBLIC_SEPOLICY_DIRS += device/acme/roadrunner-sepolicy/product/public
PRODUCT_PRIVATE_SEPOLICY_DIRS += device/acme/roadrunner-sepolicy/product/private

The old BOARD_PLAT_PUBLIC_SEPOLICY_DIR and BOARD_PLAT_PRIVATE_SEPOLICY_DIR
variables have been deprecated in favour of SYSTEM_EXT_*.

get-filehash usb_ota_update.zip -algorithm md5
Algorithm       Hash                                                                   Path
---------       ----                                                                   ----
MD5             5FD6FA7C9C9BCCE6A18102D8A1C4250D                                       D:\...

certutil -hashfile usb_ota_update.zip MD5
结果：
MD5 的 usb_ota_update.zip 哈希:
5fd6fa7c9c9bcce6a18102d8a1c4250d
CertUtil: -hashfile 命令成功完成。

tree [-aACdDfFgilnNpqstux][-I <范本样式>][-P <范本样式>][目录...]

-a 显示所有文件和目录
-d 显示目录名称而非内容
-D 列出文件或目录的更改时间。
-f 在每个文件或目录之前，显示完整的相对路径名称
-L level 限制目录显示层级，例如 -L 1

-s 列出文件或目录大小
-t 用文件和目录的更改时间排序

# 例子：把/test文件夹打包后生成一个/home/test.tar.gz的文件
tar -zcvf /home/test.tar.gz /test
tar -zcvf 打包后生成的文件名全路径 要打包的目录

# 解压：
tar -xvf test.tar.gz

压缩当前的文件夹 zip -r ./test.zip ./* -r表示递归
zip [参数] [打包后的文件名] [打包的目录路径]

system$ du -sh
1.7G	.
system$ du -sh -k
1746700	.
system$ du -sh -m
1706	

.....
Disk /dev/xvdc: 500 GiB, 536870912000 bytes, 1048576000 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

~$ sudo fdisk /dev/xvdc 

Welcome to fdisk (util-linux 2.27.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x990e1f81.

Command (m for help): n   //输入n，创建新逻辑磁盘
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p):     //回车

Using default response p.
Partition number (1-4, default 1): 1   //输入1
First sector (2048-1048575999, default 2048):   //回车
Last sector, +sectors or +size{K,M,G,T,P} (2048-1048575999, default 1048575999):    //回车

Created a new partition 1 of type 'Linux' and of size 500 GiB.

Command (m for help): ^C   //ctrl+c

~$ mkdir workspace
~$ sudo mount -t ext4 /dev/xvdc /home//workspace
~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            7.9G     0  7.9G   0% /dev
tmpfs           1.6G  9.7M  1.6G   1% /run
/dev/xvda1       83G  5.1G   74G   7% /
tmpfs           7.9G   20M  7.9G   1% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/xvdb1       13M  5.8M  7.3M  45% /mnt/iddisk
tmpfs           1.6G   32K  1.6G   1% /run/user/108
127.0.0.1:/     2.0G 1000M 1000M  50% /ctxmnt
tmpfs           1.6G  120K  1.6G   1% /run/user/16777216
/dev/xvdc       493G   70M  467G   1% /home//workspace

~$ sudo chown -R : workspace/    //用户冒号后面一个空格然后按tab选择挂载的文件夹
~$ ll
...
drwxr-xr-x  3  domain users 4096 Aug 10 14:35 workspace/  //原来是root

~$ cat /etc/fstab 
.....
# swap was on /dev/xvda5 during installation
UUID=8e68541c-22a5-4156-8bae-c4479adf10d4 none            swap    sw              0       0
/dev/xvdc /home/USER/workspace ext4 defaults 0 1   //新增行在最后

删除软件包 dpkg -r xxx.deb
连同配置文件一起删除 dpkg -r --purge xxx.deb
查看软件包信息 dpkg -info xxx.deb
查看文件拷贝详情 dpkg -L xxx.deb
查看系统中已安装软件包信息 dpkg -l
重新配置软件包 dpkg-reconfigure xxx

返回值:
　　> 0: 实际读到的字节数
　　= 0: 读完数据(读文件, 管道, socket末尾-->对端关闭, 对端未关闭会一直等待)
　　-1: 异常:
　　　　errno == EINTR被信号中断, 重启或者退出
　　　　errno == EAGAIN或者EWOULDBLOCK以非阻塞方式读, 并且没有数据
　　　　其他值: 出现错误perror eixt

root@compile03-Virtual-Machine:/etc# grep bash /etc/passwd
root:x:0:0:root:/root:/bin/bash
compile03:x:1000:1000:compile03,,,:/home/compile03:/bin/bash
uchej537:x:999:999::/home/uchej537:/bin/bash
usunw074:x:1001:1001::/home/compile03/workspace/usunw074:/bin/bash
root@compile03-Virtual-Machine:/etc#

sudo dmidecode|grep -P -A5 "Memory\s+Device"|grep Size|grep -v Range
[sudo] password for user: 
	Size: 16376 MB

# 或者使用
free -m

int fseek( FILE *stream, long offset, int origin );
第一个参数stream为文件指针
第二个参数offset为偏移量，正数表示正向偏移，负数表示负向偏移
第三个参数origin设定从文件的哪里开始偏移,可能取值为：SEEK_CUR、 SEEK_END 或 SEEK_SET
SEEK_SET： 文件开头
SEEK_CUR： 当前位置
SEEK_END： 文件结尾
其中SEEK_SET,SEEK_CUR和SEEK_END依次为0，1和2.
简言之：
fseek(fp,100L,0);把stream指针移动到离文件开头100字节处；
fseek(fp,100L,1);把stream指针移动到离文件当前位置100字节处；
fseek(fp,-100L,2);把stream指针退回到离文件结尾100字节处。

uint8_t char_2_hex(uint8_t *src)
{
    uint8_t desc;

    if((*src >= '0') && (*src <= '9'))
        desc = *src - 0x30;
    else if((*src >= 'a') && (*src <= 'f'))
        desc = *src - 0x57;
    else if((*src >= 'A') && (*src <= 'F'))
        desc = *src - 0x37;

    return desc;
}

uint8_t hex_2_char(uint8_t *src)
{
    uint8_t desc;

    if((*src >= 0) && (*src <= 9))
        desc = *src + 0x30;
    else if((*src >= 0xA) && (*src <= 0xF))
        desc = *src + 0x37;
    
    return desc;
}

enum
{
    DT_UNKNOWN = 0,
 # define DT_UNKNOWN DT_UNKNOWN
     DT_FIFO = 1,
 # define DT_FIFO DT_FIFO
     DT_CHR = 2,
 # define DT_CHR DT_CHR
     DT_DIR = 4,
 # define DT_DIR DT_DIR
     DT_BLK = 6,
 # define DT_BLK DT_BLK
     DT_REG = 8,
 # define DT_REG DT_REG
     DT_LNK = 10,
 # define DT_LNK DT_LNK
     DT_SOCK = 12,
 # define DT_SOCK DT_SOCK
     DT_WHT = 14
 # define DT_WHT DT_WHT
};

/*
* 文件名    ：    main.cpp
* 功能        ： 将字符串转换为大写，使用transform函数
*/
#include <iostream>
#include <algorithm>
using namespace std;

int main(int argc, char **argv)
{
    string strTest = "use test.";
    transform(strTest.begin(), strTest.end(), strTest.begin(), toupper);
    for (size_t i = 0; i < strTest.size(); i++) {
        cout << strTest[i];
    }
    cout << endl;
    return 0;
}

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    android:sharedUserId="android.uid.system"
    package="com.example.debugapp">
    ....

    signingConfigs {
        debug {
            storeFile file("../signApk/platform.jks")  //导入对应的keystore文件
            storePassword 'android'
            keyAlias 'androiddebugkey'
            keyPassword 'android'
        }
    }

release {
    storeFile file("platform.jks")
    storePassword 'android'
    keyAlias 'platform'
    keyPassword 'android'
    v1SigningEnabled true
    v2SigningEnabled true
}
debug {
    storeFile file("platform.jks")
    storePassword 'android'
    keyAlias 'platform'
    keyPassword 'android'
    v1SigningEnabled true
    v2SigningEnabled true
}

adb install -r -t -d Debug.apk
Performing Streamed Install
adb: failed to install Debug.apk: Failure [INSTALL_FAILED_UPDATE_INCOMPATIBLE: Package com.example.debugapp signatures do not match previously installed version; ignoring!]

buildscript {
    repositories {
        maven { url 'https://jitpack.io' }
        maven { url 'https://maven.aliyun.com/repository/public' }
        maven { url 'https://maven.aliyun.com/repository/central' }
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/public' }
        maven { url 'https://maven.aliyun.com/repository/gradle-plugin' }
        google()
        jcenter()
    }
    dependencies {
       .....
    }
}

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
        maven { url 'https://maven.aliyun.com/repository/public' }
        maven { url 'https://maven.aliyun.com/repository/central' }
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/public' }
        maven { url 'https://maven.aliyun.com/repository/gradle-plugin' }
        google()
        jcenter()
    }

 // 函数注释
    "fileheader.cursorMode": {
        // 默认字段
        "description":"",
        "param":"",
        "return":""