Android Internals

Android is a based on Linux 2.6 kernel. Android internal provide the core idea of how the Android operating system works.

Android Startup Process: Android startup process is a sequence of executions start from boot loader.

In startup of the Android system the Linux kernel calls the process "init".  Then init process calls the “Zygote” process. Zygote loads the core java classes and after initialization of Zygote is done the process start listens to a socket and waits for requests.

A special driver called "Binder" allow an efficient inter-process communications (IPC)) in which allow references to objects are passed between processes. The real objects are stored in Shared Memory. This way the communication between the processes is optimized as less data must be transferred.

The bellow diagram illustrates the execution flow of the Android Startup Process.   

For Example a new app is started on android as follows

● onClick (Launcher)

● startActivity (Activity.java)

● <Binder>

● ActivityManagerService

● startViaZygote(Process.java)

● <Socket>

● Zygote