The document provides an overview of the history and architecture of the Android operating system. It discusses how Android was founded and later acquired by Google. It describes the Open Handset Alliance consortium and explains that Android is based on the Linux kernel and allows development using Java. It outlines Android's layered architecture and use of the Binder IPC mechanism. It also touches on Android security features like application signing, permissions, and sandboxing of apps.

1. Basic Android
Operating System
Yong Heui Cho @ Mokwon University
Some of slides are referred to:
[1] Nitin Ramchandani, Android OS, slideshare.

2. 2
Smart Device Structure
1. Introduction to Smart Devices
2. Android Studio Tutorial
3. Basic Android OS
4. Android – Application
Framework

3. 3
Android

4. 4
Android History
• Android Inc. was founded in Oct. 2003 by Andy
Rubin, Nick Sears, Chris White and Rich Miner.
• Google acquired it in August 2005.
• On November 5, 2007, the Open Handset
Alliance, a consortium of several companies which
include Broadcom Corporation, Google, HTC, Intel,
T-Mobile and Texas Instruments unveiled itself.
□ Courtesy to Nitin Ramchandani, Android OS, slideshare.

5. 5
What is the Open Handset Alliance (OHA)?
• Devoted to advancing open standards for mobile devices
• Develop technologies that will significantly lower the cost of developing and
distributing mobile devices and services.
License
Android is under of the Apache Software License (ASL).
Open Handset Alliance
□ Courtesy to Nitin Ramchandani, Android OS, slideshare.

6. 6
Android Operating System (OS)
• A software platform and operating system for mobile devices
• Based on the Linux kernel
• Developed by Google and later the Open Handset Alliance (OHA)
• Allows writing managed code in the Java language
• Possibility to write applications in other languages and compiling it to
native code.
• At least 2,000,000 Application available in 2016
• It run on java based and object-oriented based application
What is Android?
□ Courtesy to Nitin Ramchandani, Android OS, slideshare.

7. 7
Android Version List

8. 8
Android
Architecture

9. 9

10. 10
HW Abstraction Layer (HAL)

11. 11
Concept of OS
• Operating System
– System SW that manages computer HW and SW
resources and provides common services for
computer programs

12. 12
Why OS?
• Requirements of OS
– OS must shield the details of the HW from the application
programs, and thus from the user.
– OS has to substitute a set of abstract services to the
application programs, to replace the physical HW services.
When applications use these abstract services, the
operations must be translated into real HW operations.
– OS must act as a resource manager, optimizing the use of
the resources, and protecting them against misuse and
abuse. When a system provides multiuser or multitasking
capabilities, resources must be allocated fairly and
equitably amongst a number of competing requests.

13. 13
Linux Kernel
•Android is built on Linux kernel, but it is not the Linux.
•No native windowing system (X window system)
•No glibc (GNU C Library) support
•Does not support all set of standard GNU libraries
□ Courtesy to Nitin Ramchandani, Android OS, slideshare.

14. 14
Concept of Kernel
• A main part of OS that manages input/output
requests from software and translates them into
data processing instructions for the CPU and
other electronic components of a computer

15. 15
• Great memory and process management
• Great permissions based security model
• Proven driver model
• Support for shared libraries
• It’s already open source
Why Linux?
□ Courtesy to Nitin Ramchandani, Android OS, slideshare.

16. 16
• Based on the standard Linux Power
Management, Android has its own
component.
•Application uses user space library to inform the framework
about its constrains..
•Constraints are implemented using lock mechanism..
Power Management
□ Courtesy to Nitin Ramchandani, Android OS, slideshare.

17. 17
•Driver to facilitate inter-process communication
between applications and services..
• A pool of threads is associated to each application to
process incoming IPC (Inter-Process Communication)
•The driver performs mapping off object between two
processes
•“Binder” uses an object reference as an address in a
process’s memory space
Binder
□ Courtesy to Nitin Ramchandani, Android OS, slideshare.

18. 18
Android and Security
• Application signing
– Process of generating private and public keys and public-key
certificates, signing and optimizing the application
• Permission

19. 19
Concept of Sandbox
• Android uses Linux facilities such as process-level security,
user and group IDs that are associated with the
application, and permissions to enforce what operations
an application is allowed to perform

20. 20
Allowing Access
• You first must sign those applications using the same private key
and you then must assign to them the same Linux user ID using
the manifest file, by defining the manifest attribute
android:sharedUserId with the same value/name.