Android is an open-source, Linux-based operating system developed by Google and the Open Handset Alliance. It was originally developed by Android Inc. which was acquired by Google in 2005. Some key features of Android include its open nature which allows customization and third-party applications, regular updates to incrementally improve the OS, and the ability to run on a variety of hardware configurations. The Android software stack consists of applications running on top of native libraries and Android runtime, which uses the Linux kernel.

1. Android OS
by
Serhan Özbey
A project submitted
in requirements for
EENG 363
COMPUTER
ARCHITECTURE
Department of Engineering
YAŞAR UNIVERSITY
21.01.14

2. INTRODUCTION
World is contracting with the growth of
mobile phone technology. As the
number of users is increasing day by
day, facilities are also increasing.
Starting with simple regular handsets
which were used just for making phone
calls, mobiles have changed our lives
and have become part of it.

3. INTRODUCTION
Now they are not used just for making
calls but they have innumerable uses
and can be used as a Camera , Music
player, Tablet PC, T.V. , Web browser
etc. And with the new
technologies, new software and
operating systems are required.

4. INTRODUCTION
Mobile OS has greatly evolved from Palm
OS in 1996 to Windows pocket PC in
2000 then to Blackberry OS and
Android.

5. INTRODUCTION
One of the most widely used mobile OS these
days is ANDROID. Android is a software bunch
comprising not only operating system but also
middleware and key applications.

6. HISTORY
Android, Inc. was founded in Palo
Alto, California in October 2003 by Andy
Rubin , Rich Miner , Nick Sears , and Chris
White to develop, in Rubin's words "smarter
mobile devices that are more aware of its
owner's location and preferences"

7. HISTORY
The early intentions of the company were to
develop an advanced operating system
for digital cameras, when it was realised that
the market for the devices was not large
enough, and diverted their efforts to
producing a smartphone operating system to
rival those of Symbian and Windows Mobile.

8. Google acquired Android Inc. on August
17, 2005; key employees of Android
Inc., including Rubin, Miner and White, stayed
at the company after the acquisition Not much
was known about Android Inc. at the time, but
many assumed that Google was planning to
enter the mobile phone market with this move

9. On November 5, 2007, the Open Handset
Alliance, a consortium of technology companies
including Google, device manufacturers such
as HTC, Sony and Samsung, wireless carriers such
as Nextel and T-Mobile, and chipset makers such
as Qualcomm and Texas Instruments, unveiled
itself, with a goal to develop open standards for
mobile devices. That day, Android was unveiled as
its first product, a mobile device platform built on
the Linux kernel version 2.6.

11. ANDROID vs. iOS
As iOS is getting a lot of nice reviews and
improving everytime than it’s old versions .
But it still falls short of Android in several
areas like freedom of open-source editing and
third-party applications in Android made it
one-step forward from iOS in a short time .

13. If you want to customize your smartphone, the
sky's the limit with Android. End-users can alter
whatever they want.
Visible file system of Android unsures end-users a
comfortable file transferring system . It's as easy as
drag-and-drop. Apple doesn't give you that kind of
access to all your files .

14. Since 2008, Android has seen numerous
updates which have incrementally improved
the operating system, adding new features
and fixing bugs in previous releases.
DEVELOPEMENT & UPDATES

15. Android is developed in private by Google
until the latest changes and updates are
ready to be released, at which point the
source code is made available publicly..
This source code will only run without
modification on select devices, usually
the Nexus series of devices.

16. The source code is, in turn, adapted by OEMs
to run on their hardware. Android's source
code does not contain the often
proprietary device drivers that are needed
for certain hardware components

18. Each major release is named in alphabetical
order after a dessert or sugary treat; for
example, version 1.5 Cupcake was followed
by 1.6 Donut. The latest released version is
4.4.2 KitKat, which was released on 9
December 2013.

21. For devices not under
the Nexus brand, updates often arrive
months from the time the given version is
officially released. This is caused partly due to
the extensive variation in hardware of
Android devices, to which each update must
be specifically tailored, as the official Google
source code only runs on their
flagship Nexus devices.

22. Google Nexus is a line of mobile devices co-
developed by Google and
several OEM partners, that run
the Android operating system. Devices in the
Nexus series do not have manufacturer
or wireless carrier modifications to Android
(such as custom graphical user interfaces), and
have an unlockable bootloader to allow further
development and end-user modification.

23. FEATURES & SPECIFICATIONS
Android is a powerful Operating System
supporting a large number of applications
in Smart Phones. These applications make life
more comfortable and advanced for the
users. Hardwares that support Android are
mainly based on ARM architecture platform.

24. Components of Android Architecture
• Applications
• Apps Framework
• Libraries
• Android Runtime ( Dalvik )
• Kernel ( Linux )

26. KERNEL
As of January 2014, current Android
versions consist of a kernel based on
the Linux kernel's longterm 3.4
branch, varying in version numbers
depending on the actual Android device.
Android versions older than 4.0 Ice Cream
Sandwich were based on the Linux kernel
versions 2.6.x.

28. LIBRARIES
Some of the common libraries
available in Android are media
libraries, libc, SQLite, Surface
Manager, webkit, etc. LibC includes all
the major System C library files. SQLite
features all the relational database
system files.

29. On top of Linux kernel , there are the middleware
, libraries and APIs written in C , and application
software running on an application framework .
Android uses the Dalvik virtual machine with just-in-
time compilation to run Dalvik "dex-code" (Dalvik
Executable), which is usually translated from the Java
bytecode.
SOFTWARE STACK

31. Android applications are written in java
programming language. Android is
available as open source for developers
to develop applications which can be
further used for selling in android
market. There are around 200000
applications developed for android with
over 3 billion+ downloads.

32. Android relies on Linux
version 2.6 for core
system services such as
security, memory
management, process
management, network
stack, and driver
model. For software
development, Android
provides Android
SDK (Software
development kit).

33. Android comes with an Android market ( now
Google Play ) which is an online software
store. It was developed by Google. It allows
Android users to select, and download
applications developed by third party
developers and use them. There are around
2.0 lack+ games, application and widgets
available on the market for users.

36. Thank you for listening !