Android system startup process simple record

This document documents the Android system boot process, including the process from Linux Kernerl to luancher boot completion:

1, after the Linux kernel completes the system setup, it will look for the ' init ' file in the system files, then start the root process or the first process of the system;

2, the INIT process is the Linux kernel to complete the system setup after the first process started or the root process, it is the parent process of all other processes, it has two functions, one is mount directory, such as/sys,/dev, etc., Second, run the init.rc script or the init.xxx.rc script;

3. The init.rc script is Android's own set of initialization scripts, which run the init process in the previous step. RC script to build several basic services, the most important of which is the ServiceManager and zygote processes, the zygote process is established after the establishment of real Android running space;

4, zygote process will fork out a systemserver process, in the process will start all Android services, such as pms,ams, etc.;

5. After all Android services are started in the Systemserver in the previous step, the Xxx.systemready (callback) method is called to notify each service system that it is ready. Where the Launcher app is launched in a call to Activitymanagerservice.systemready ()

Android system startup process simple record