Information Technology Reference
In-Depth Information
The Linux kernel layer
Android OS is built on top of the Linux kernel with some architectural changes made by
Google. There are several reasons for choosing the Linux kernel. Most importantly, Linux
is a portable platform that can be compiled easily on different hardware. The kernel acts as
an abstraction layer between the software and hardware present on the device. Consider the
case of a camera click. What happens when you click a photo using the camera button on
your device? At some point, the hardware instruction (pressing a button) has to be conver-
ted to a software instruction (to take a picture and store it in the gallery). The kernel con-
tains drivers to facilitate this process. When the user clicks on the button, the instruction
goes to the corresponding camera driver in the kernel, which sends the necessary com-
mands to the camera hardware, similar to what occurs when a key is pressed on a keyboard.
In simple words, the drivers in the kernel command control the underlying hardware. As
shown in the preceding figure, the kernel contains drivers related to Wi-Fi, Bluetooth,
USB, audio, display, and so on.
The Linux kernel is responsible for managing the core functionality of Android, such as
process management, memory management, security, and networking. Linux is a proven
platform when it comes to security and process management. Android has taken leverage
of the existing Linux open source OS to build a solid foundation for its ecosystem. Each
version of Android has a different version of the underlying Linux kernel. The current
KitKat Android version is rumored to use Linux kernel 3.8 (
http://www.phonearena.com/
