Android OS Architecture
This address: Http://blog.csdn.net/caroline_wendy
structure diagram :
1. Linux kernel (kernel space)portability, security, and utility features.
2. Local tier (user space)
(1) HAL (Hardware abstraction Layer):The hardware abstraction layer, which uses a shared local library to abstract each major device driver, is an object that supports the common interface of any major hardware driver.
(2) Local library :support for Android application framework layer.
(3) Local daemon :The daemon, which is usually called the daemon process, is the background service process in Linux. Service Manager, wireless Interface layer Daemon (Radio Interface layer Daemon), installation daemon (install Daemon), Media server, Android Debugger Daemon (Android debug Bridge Daemon), etc.;
(4) Local tools:Linux command-line tool that initiates the INIT process for all local daemons.
3. Delvik Virtual MachineAndroid Virtual machine, Java bytecode is compiled again into Delvik bytecode, mainly based on Java Standard Edition;
4. Application Frameworklots of libraries and services, rich documentation, Java libraries built for Android, and Java standard libraries;
5. Application
(1) Application Packages (apk,android application package):Android manifest files, Dalvik executables (. Dex), Resources (Resource), local libraries (libraries in other languages), signatures (application authors);
(2) application signature:Each application will have a signature, or use the default signature, location:. Android/debug.keystore.
(3) application distribution:Google market, other markets.
Android-android Operating System Architecture
