Android系统启动过程分析

本文主要介绍Android系统的启动过程，以Androidinit进程之后部分为主，init之前部分同标准Linux内核启动完全相同。于Android启动过程复杂，涉及C、C++及java部分内容，本文以流程分析为主线旨在让大家在分析Android系统时有个清晰的思路。鉴于本人水平有限，如有阐述不正之处，还请不吝指正，感激不尽！

系统启动大致可分为一下几个阶段：

• 　　bootloader---初始化、从Flash读取Kernel镜像及一些必须的配置信息，引导kernel启动

• 　　linuxkernel启动linux内核

• 　　init进程启动

• 　　init进程读取init.rc启动必要的daemon程序，如：adbd、vold、netd、等

• 　　init进程启动servicemanager---随后详细分析其过程

• 　　init进程启动zygote ---随后详细分析其过程

• 　　JAVA部分的Service启动

• 　　init进程启动mediaserver---多媒体本地服务启动

本文主要分析android部分的启动，涉及范围为servicemanager启动到android系统的Java部分的Service

-Android system starting procedure analyze .doc

This paper mainly introduces the Android system startup process, to Androidinit after process part is given priority to, init with standard Linux kernel part before start completely the same. In Android start-up process complex, involving C, C++ and Java part, this paper to process analysis to let everybody as the main analysis is a system in Android clear ideas. In view of the limited my level, if there is the place of paper is not straight, please not stingy correct, I appreciate!

The system can be roughly divided into a few start-up stage:

· bootloader-initialization, read from Flash Kernel image and some must configuration information, so as to guide the Kernel start

· linuxkernel start Linux kernel

· init process start

· init process read init. Rc start daemon necessary procedures, such as: adbd, vold, netd, etc

· init process start servicemanager-then detailed analysis of the process

· init process start zygote-then detailed