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/[email protected]... [ 22.592402] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.603000] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.612471] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.622456] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.631375] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.640973] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.650100] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.659732] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.669427] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.678653] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.689081] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.699269] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.708675] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.718172] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.727480] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.737140] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.746312] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.755606] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.764512] c3 init: Parsing file /vendor/etc/init/[email protected]... [ 22.773805] c3 init: Parsing file /vendor/etc/init/[email protected]...
想着以前都是在init.rc中把这些脚本import解析执行，搜了一大圈没找到，又去SystemServer.java中找，也没找到，回过头分析log，“Parsing directory” 找到
./core/init/init_parser.cpp: LOG(INFO) << "Parsing directory " << path << "...";
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 = 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<std::string>& args, size_t start_index, size_t end_index) {
Parser& parser = Parser::GetInstance();
if (end_index <= start_index) {
// Fallbacks for partitions on which early mount isn'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？
接口和软件包
HIDL 是围绕接口进行编译的，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，例如 package.subpackage。已发布的 HIDL 软件包的根目录是 hardware/interfaces 或 vendor/vendorName（例如 Pixel 设备为 vendor/google）。软件包名称在根目录下形成一个或多个子目录；定义软件包的所有文件都位于同一目录下。例如，package [email protected] 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：
| 软件包前缀 | 位置 |
|---|---|
android.hardware.* |
hardware/interfaces/* |
android.frameworks.* |
frameworks/hardware/interfaces/* |
android.system.* |
system/hardware/interfaces/* |
android.hidl.* |
system/libhidl/transport/* |
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（如果存在）并不定义接口，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，经常会提到HIDL，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，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，会通过hidl-gen转换成out/soong/.intermediates/hardware/interfaces/power/1.0/[email protected]_genc++/gen/android/hardware/power/1.0/PowerAll.cpp文件，为了深入了解，介绍相关原理,首先分析hidl-gen。
hidl-gen源码路径：system/tools/hidl，是在ubuntu上可执行的二进制文件。
使用方法：hidl-gen -o output-path -L language (-r interface-root) fqname
例子：
hidl-gen -Lmakefile -r android.hardware:hardware/interfaces -r android.hidl:system/libhidl/transpordiff --git a/update-base-files.sh b/update-base-files.sh
index 1eb6b51..b5b1a99 100755
--- a/update-base-files.sh
+++ b/update-base-files.sh
@@ -22,9 +22,9 @@ options="-Lexport-header \
hidl-gen $options \
-o hardware/libhardware/include/hardware/sensors-base.h \
[email protected]
-hidl-gen $options \
- -o hardware/libhardware/include/hardware/nfc-base.h \
- [email protected]
+#hidl-gen $options \
+# -o hardware/libhardware/include/hardware/nfc-base.h \
+# [email protected]
hidl-gen $options \
-o hardware/libhardware/include/hardware/gnss-base.h \
[email protected]
参考：
https://source.android.com/devices/architecture/hidl/interfaces
https://blog.csdn.net/xiaosayidao/article/details/75577940