android8.x的HIDL众多服务启动时的优化

在Andorid8.x系统之前&＃xff0c;Android系统的服务不是在SystemServer.java中启动&＃xff0c;就在init进程初始化xxx.xxx.rc中启动。

而Android8.x开始&＃xff0c;会发现像/vendor/etc/init/android.hardware.*&＃64;2.0-service.rc这种类型的服务和初始化不知道在什么地方加载起来&＃xff0c;本文主要这个这种情况进行分析和优化。

本文转自&＃xff1a;https://blog.csdn.net/touxiong/article/details/80537777

优化开机速度--抓log发现很多用不着的service

[ 22.577559] c3 init: Parsing directory /vendor/etc/init...
[ 22.583263] c3 init: Parsing file /vendor/etc/init/android.hardware.audio&＃64;2.0-service.rc...
[ 22.592402] c3 init: Parsing file /vendor/etc/init/android.hardware.biometrics.fingerprint&＃64;2.1-service.rc...
[ 22.603000] c3 init: Parsing file /vendor/etc/init/android.hardware.bluetooth&＃64;1.0-service.rc...
[ 22.612471] c3 init: Parsing file /vendor/etc/init/android.hardware.camera.provider&＃64;2.4-service.rc...
[ 22.622456] c3 init: Parsing file /vendor/etc/init/android.hardware.cas&＃64;1.0-service.rc...
[ 22.631375] c3 init: Parsing file /vendor/etc/init/android.hardware.configstore&＃64;1.0-service.rc...
[ 22.640973] c3 init: Parsing file /vendor/etc/init/android.hardware.drm&＃64;1.0-service.rc...
[ 22.650100] c3 init: Parsing file /vendor/etc/init/android.hardware.dumpstate&＃64;1.0-service.rc...
[ 22.659732] c3 init: Parsing file /vendor/etc/init/android.hardware.gatekeeper&＃64;1.0-service.rc...
[ 22.669427] c3 init: Parsing file /vendor/etc/init/android.hardware.gnss&＃64;1.0-service.rc...
[ 22.678653] c3 init: Parsing file /vendor/etc/init/android.hardware.graphics.allocator&＃64;2.0-service.rc...
[ 22.689081] c3 init: Parsing file /vendor/etc/init/android.hardware.graphics.composer&＃64;2.1-service.rc...
[ 22.699269] c3 init: Parsing file /vendor/etc/init/android.hardware.health&＃64;1.0-service.rc...
[ 22.708675] c3 init: Parsing file /vendor/etc/init/android.hardware.keymaster&＃64;3.0-service.rc...
[ 22.718172] c3 init: Parsing file /vendor/etc/init/android.hardware.light&＃64;2.0-service.rc...
[ 22.727480] c3 init: Parsing file /vendor/etc/init/android.hardware.media.omx&＃64;1.0-service.rc...
[ 22.737140] c3 init: Parsing file /vendor/etc/init/android.hardware.memtrack&＃64;1.0-service.rc...
[ 22.746312] c3 init: Parsing file /vendor/etc/init/android.hardware.sensors&＃64;1.0-service.rc...
[ 22.755606] c3 init: Parsing file /vendor/etc/init/android.hardware.usb&＃64;1.1-service.rc...
[ 22.764512] c3 init: Parsing file /vendor/etc/init/android.hardware.vibrator&＃64;1.0-service.rc...
[ 22.773805] c3 init: Parsing file /vendor/etc/init/android.hardware.wifi&＃64;1.0-service.rc..

想着以前都是在init.rc中把这些脚本import解析执行&＃xff0c;搜了一大圈没找到&＃xff0c;又去SystemServer.java中找&＃xff0c;也没找到&＃xff0c;回过头分析log&＃xff0c;“Parsing directory”  找到

./core/init/init_parser.cpp:    LOG(INFO) <<"Parsing directory " <

./core/init/init_parser.cpp
bool Parser::ParseConfig(const std::string& path) {if (is_dir(path.c_str())) {return ParseConfigDir(path);}return ParseConfigFile(path);
}

继续搜索

std::string bootscript &＃61; GetProperty("ro.boot.init_rc", "");if (bootscript.empty()) {parser.ParseConfig("/init.rc");parser.set_is_system_etc_init_loaded(parser.ParseConfig("/system/etc/init"));parser.set_is_vendor_etc_init_loaded(parser.ParseConfig("/vendor/etc/init"));parser.set_is_odm_etc_init_loaded(parser.ParseConfig("/odm/etc/init"));} else {parser.ParseConfig(bootscript);parser.set_is_system_etc_init_loaded(true);parser.set_is_vendor_etc_init_loaded(true);parser.set_is_odm_etc_init_loaded(true);

static void import_late(const std::vector& args, size_t start_index, size_t end_index) {Parser& parser &＃61; Parser::GetInstance();if (end_index <&＃61; start_index) {// Fallbacks for partitions on which early mount isn&＃39;t enabled.if (!parser.is_system_etc_init_loaded()) {parser.ParseConfig("/system/etc/init");parser.set_is_system_etc_init_loaded(true);}if (!parser.is_vendor_etc_init_loaded()) {parser.ParseConfig("/vendor/etc/init");parser.set_is_vendor_etc_init_loaded(true);}if (!parser.is_odm_etc_init_loaded()) {parser.ParseConfig("/odm/etc/init");parser.set_is_odm_etc_init_loaded(true);}

那请问 /vendor/etc/init 是在上面蓝色还是红色出解析的呢&＃xff1f;

接口和软件包

HIDL 是围绕接口进行编译的&＃xff0c;接口是面向对象的语言使用的一种用来定义行为的抽象类型。每个接口都是软件包的一部分。

软件包

软件包名称可以具有子级&＃xff0c;例如 package.subpackage。已发布的 HIDL 软件包的根目录是 hardware/interfaces 或 vendor/vendorName&＃xff08;例如 Pixel 设备为 vendor/google&＃xff09;。软件包名称在根目录下形成一个或多个子目录&＃xff1b;定义软件包的所有文件都位于同一目录下。例如&＃xff0c;package android.hardware.example.extension.light&＃64;2.0 可以在 hardware/interfaces/example/extension/light/2.0 下找到。
下表列出了软件包前缀和位置&＃xff1a;

软件包目录中包含扩展名为 .hal 的文件。每个文件均必须包含一个指定文件所属的软件包和版本的 package 语句。文件 types.hal&＃xff08;如果存在&＃xff09;并不定义接口&＃xff0c;而是定义软件包中每个接口可以访问的数据类型.

现在删除部分serveice:

hidl-gen工具

在Treble架构中&＃xff0c;经常会提到HIDL&＃xff0c;首先介绍和HIDL相关的一个工具hidl-gen,系统定义的所有的.hal接口&＃xff0c;都是通过hidl-gen工具转换成对应的代码。比如hardware/interfaces/power/1.0/IPower.hal&＃xff0c;会通过hidl-gen转换成out/soong/.intermediates/hardware/interfaces/power/1.0/android.hardware.power&＃64;1.0_genc&＃43;&＃43;/gen/android/hardware/power/1.0/PowerAll.cpp文件&＃xff0c;为了深入了解&＃xff0c;介绍相关原理,首先分析hidl-gen。

hidl-gen源码路径&＃xff1a;system/tools/hidl&＃xff0c;是在ubuntu上可执行的二进制文件。

使用方法&＃xff1a;hidl-gen -o output-path -L language (-r interface-root) fqname

列子&＃xff1a;

hidl-gen -Lmakefile -r android.hardware:hardware/interfaces -r android.hidl:system/libhidl/transpor


diff --git a/update-base-files.sh b/update-base-files.sh
index 1eb6b51..b5b1a99 100755
--- a/update-base-files.sh
&＃43;&＃43;&＃43; b/update-base-files.sh
&＃64;&＃64; -22,9 &＃43;22,9 &＃64;&＃64; options&＃61;"-Lexport-header \hidl-gen $options \-o hardware/libhardware/include/hardware/sensors-base.h \android.hardware.sensors&＃64;1.0
-hidl-gen $options \
- -o hardware/libhardware/include/hardware/nfc-base.h \
- android.hardware.nfc&＃64;1.0
&＃43;#hidl-gen $options \
&＃43;# -o hardware/libhardware/include/hardware/nfc-base.h \
&＃43;# android.hardware.nfc&＃64;1.0hidl-gen $options \-o hardware/libhardware/include/hardware/gnss-base.h \android.hardware.gnss&＃64;1.0

参考&＃xff1a;https://source.android.com/devices/architecture/hidl/interfaces

           https://blog.csdn.net/xiaosayidao/article/details/75577940