android on x86

Shelve in

Mobile Computing

User level:

Beginning–Advanced

BOOKS FOR PROFESSIONALS BY PROFESSIONALS®

Android on x86

Android on x86: an Introduction to Optimizing for Intel® Architecture serves two

main purposes. First, it makes the case for adapting your applications onto Intel’s

x86 architecture, including discussions of the business potential, the changing

landscape of the Android marketplace, and the unique challenges and opportunities

that arise from x86 devices. The fundamental idea is that extending your applications

to support x86 or creating new ones is not difficult, but it is imperative to know all

of the technicalities. This book is dedicated to providing you with an awareness of

these nuances and an understanding of how to tackle them.

Second, and most importantly, this book provides a one-stop detailed resource

for best practices and procedures associated with the installation issues, hardware

optimization issues, software requirements, programming tasks, and perfor￾mance optimizations that emerge when developers consider the x86 Android

devices. Optimization discussions dive into native code, hardware acceleration,

and advanced profiling of multimedia applications. The authors have collected

this information so that you can use the book as a guide for the specific require￾ments of each application project.

This book is not dedicated solely to code; instead it is filled with the information

you need in order to take advantage of x86 architecture. It will guide you through

installing the Android SDK for Intel Architecture, help you understand the differ￾ences and similarities between processor architectures available in Android

devices, teach you to create and port applications, debug existing x86 appli￾cations, offer solutions for NDK and C++optimizations, and introduce the Intel

Hardware Accelerated Execution Manager. This book provides the most useful

information to help you get the job done quickly while utilizing best practices.

Krajci

Cummings

9 781430 261308

ISBN 978-1-4302-6130-8

53999

www.it-ebooks.info

For your convenience Apress has placed some of the front

matter material after the index. Please use the Bookmarks

and Contents at a Glance links to access them.

www.it-ebooks.info

v

Contents at a Glance

About the Authors��������������������������������������������������������������������������� xxi

Acknowledgments������������������������������������������������������������������������ xxiii

Introduction������������������������������������������������������������������������������������xxv

■Chapter 1: History and Evolution of the Android OS����������������������� 1

■Chapter 2: The Mobile Device and Operating System Landscape������9

■Chapter 3: Beyond the Mobile App—A Technology Foundation ��� 17

■Chapter 4: Android Development—Business Overview

and Considerations����������������������������������������������������������������������� 25

■Chapter 5: The Intel Mobile Processor ����������������������������������������� 33

■Chapter 6: Installing the Android SDK for Intel

Application Development�������������������������������������������������������������� 47

■Chapter 7: Creating and Porting NDK-Based

Android Applications �������������������������������������������������������������������� 75

■Chapter 8: Debugging Android ��������������������������������������������������� 131

■Chapter 9: Performance Optimizations for Android

Applications on x86�������������������������������������������������������������������� 185

■Chapter 10: x86 NDK and C/C++ Optimizations ������������������������� 259

■Chapter 11: Using Intel Hardware Accelerated Execution

Manager on Windows, Mac OS, and Linux to Speed Up

Android on x86 Emulation ���������������������������������������������������������� 285

www.it-ebooks.info

■ Contents at a Glance

vi

■Chapter 12: Performance Testing and Profiling Apps

with Platform Tuning������������������������������������������������������������������ 303

■Appendix A: References�������������������������������������������������������������� 331

Index���������������������������������������������������������������������������������������������� 343

www.it-ebooks.info

xxv

Introduction

We wrote Android on x86: an Introduction to Optimizing for Intel® Architecture to

provide a one-stop, detailed resource for the topic’s best practices and procedures.

The book encompasses the installation issues, hardware optimization issues, software

requirements, programming tasks, and performance optimizations that emerge when you

consider programming for x86-based Android devices. Having worked on related projects

ourselves, we committed to collecting our experience and information into one book

which could be used as a guide through any project’s specific requirements. We dove into

fine-tuned optimizations, native code adjustments, hardware acceleration, and advanced

profiling of multimedia applications.

The book is not dedicated solely to code, although you’ll find plenty of code samples

and case studies inside. Instead, we’ve filled Android on x86 with the information you

need in order to take advantage of the x86 architectures. We will guide you through

installing the Android Software Development Kit for Intel Architectures, help you

understand the differences and similarities between the processors available for

commercial Android devices, teach you to create and port applications, debug existing

x86 applications, offer solutions for NDK and C++ optimizations, and introduce the

Intel Hardware Accelerated Execution Manager. The information we’ve pulled together

provides the most useful help for getting your development job done quickly and well.

Why Android on x86?

In 2011, we experienced a paradigm shift in how we communicate. Smart device sales

outpaced personal computer sales for the first time. This changing of the guard emerged

from three sources:

• Our increasing professional and social need for open, constant

communication

• The lower cost and compelling new features of smartphones and

tablets

• The increased ease of use and availability of mobile apps

In the next few years, mobile access to the Internet is likely to exceed access via

laptops and desktops; the hardware we use to communicate may change, but our passion

for connectivity anytime, anywhere is sure to continue.

www.it-ebooks.info

■ Introduction

xxvi

Holding more than 80% of the market share for smartphone shipments worldwide,

Google’s Android operating system has proven to be the leader of this mobile revolution.

The key reasons for the success of Android are its open platform and flexible partnerships.

The wealth of open-source resources available for Android developers spurs the creation

of more apps, giving consumers more choices. In addition, the open platform supports a

competitive and diverse hardware environment.

As the market for high-performing mobile devices widens, Google has teamed up

with Intel to envision the next frontier for Android: getting the OS to run on devices with

Intel architectures inside. The journey towards Android on Intel architectures began

unofficially in 2009, when a group of developers started the open source Android-x86

initiative in order to port Android onto devices running on Intel x86 processors. Soon

after, with the official Android on Intel architecture project, Intel started contributing

code and resources to the Android Open Source Project (AOSP). In 2012, the first Android

smartphones featuring Intel processors were released to market worldwide; by late 2013,

Android smartphones and tablets with unprecedented processing power were entering

United States’ markets. Most recently, the two groups committed to getting Android to

run on 64-bit devices, including netbooks, laptops, and traditional desktop PCs, meaning

that in 2014, Android will break into a market historically dominated by Microsoft

Windows and Apple OSX. Android will bring its enormous, thriving community of

application developers forward to a wide range of devices and hardware architectures.

The collaboration brings a number of benefits from both groups. Intel’s x86

architecture comes with 35 years of well-documented processing excellence, a

mature developer ecosystem, and a sophisticated set of development tools. In terms

of performance, Intel’s latest chips strike a balance between high performance and

low power consumption that is ideal for smartphones, tablets, and netbooks. Native

x86 emulator support is a key feature of the latest Android SDK versions, and Intel is

dedicated to providing developers with a host of tools for optimizing Android application

performance for their chips.

By expanding onto both 32-bit and 64-bit architectures, the Android landscape is

opening wide. More Android-equipped mobile devices with Intel processors are hitting

shelves and our fingertips every day, and the upcoming addition of Intel-powered

netbooks and laptops will shape the environment into something amazing. A new

Android experience will take shape, one that remains diverse and becomes optimized for

larger screens, robust multi-windowing, and ever-faster processor speeds. It’s an exciting

time, and we hope that developers will seize this new opportunity to expand Android’s

horizons.

Who Is This Book For?

This book is aimed at two general categories of people: developers and those interested

in choosing Android x86 as a platform for their applications. With this in mind, the

beginning chapters focus on much more high-level, nontechnical questions, so that

people from all technical backgrounds can make informed choices. The later chapters

focus heavily on the developers’ side of the world, starting with a basic foundation of

microprocessor architectures and Android development environments and then building

www.it-ebooks.info

■ Introduction

xxvii

to very advanced, performance-focused content. Our goal is to reach the entire spectrum

of people who are interested in Android on x86, and to do our best at getting you the

answers you need.

We really hope you enjoy the book. We certainly have enjoyed exploring this

topic, and look forward to seeing what will happen in this rapidly-expanding field in

the upcoming years. We would also like to note that while we may know a thing or

two about Android, we recognize that we are certainly not the most knowledgeable

about everything. Feel free to challenge any information that you find in this book – we

encourage you to use outside resources and really involve yourself in the communities

that surround this technology!

www.it-ebooks.info

1

Chapter 1

History and Evolution of

the Android OS

I’m going to destroy Android, because it’s a stolen product. I’m willing to

go thermonuclear war on this.

—Steve Jobs, Apple Inc.

Android, Inc. started with a clear mission by its creators. According to Andy Rubin, one of

Android’s founders, Android Inc. was to develop “smarter mobile devices that are more

aware of its owner’s location and preferences.” Rubin further stated, “If people are smart,

that information starts getting aggregated into consumer products.” The year was 2003

and the location was Palo Alto, California. This was the year Android was born.

While Android, Inc. started operations secretly, today the entire world knows

about Android. It is no secret that Android is an operating system (OS) for modern day

smartphones, tablets, and soon-to-be laptops, but what exactly does that mean? What did

Android used to look like? How has it gotten where it is today? All of these questions and

more will be answered in this brief chapter.

Origins

Android first appeared on the technology radar in 2005 when Google, the multibillion￾dollar technology company, purchased Android, Inc. At the time, not much was known

about Android and what Google intended on doing with it. Information was sparse until

2007, when Google announced the world’s first truly open platform for mobile devices.

The First Distribution of Android

On November 5, 2007, a press release from the Open Handset Alliance set the stage for

the future of the Android platform. The alliance stated some of the goals of Android

as, “fostering innovation on mobile devices and giving consumers a far better user

experience than much of what is available on today’s mobile platforms.”

www.it-ebooks.info

CHAPTER 1 ■ History and Evolution of the Android OS

2

At that time, more than 2 billion mobile phones were used worldwide, compared to

the 4.6 billion used as of 2010. However, there was no coordination of platforms between

the various companies that provided mobile devices. With the introduction of Android,

a single operating system removed the need for reimplementation of phone applications

and middleware. The companies creating new devices could now focus much more

intently on the hardware and underlying components.

But these companies weren’t the only ones who benefited from the launch of

Android; software developers could now release applications to multiple devices with

very few changes to the underlying code base. This allowed developers to spend more

time working on the applications these phones were running and create the rich and

impressive applications that we are all used to. This was in part due to the open source

philosophy behind Android, and the Apache license, which is the license used on most of

the Android source code.

Open Source Apache License

The Apache License is just one of many different licenses that exist in the open source

community. While there are differences in all of these licenses, they all facilitate the same

open source mindset that is best summed up as follows:

“Free software” is a matter of liberty, not price. To understand the concept,

you should think of “free” as in “free speech,” not as in “free beer.”

—Richard M. Stallman

The Apache License specifically grants freedom to use the software for any

purpose, as well as the ability to distribute, modify, or distribute modified versions.

The Apache License is also permissive, meaning that modified versions do not have to

succumb to the Apache License. For more information about the Apache License, go to

http://www.apache.org/licenses/LICENSE-2.0.

What Is Android?

So what exactly is Android? Android OS is the open source technology stack that runs

on over 400 million devices worldwide. This technology stack consists of various

components that allow developers and device manufacturers to work independently.

This can be broken into five primary pieces—applications, application frameworks,

native libraries, Android runtime, and the Linux kernel—as shown in Figure 1-1.

www.it-ebooks.info

CHAPTER 1 ■ History and Evolution of the Android OS

3

Applications

The applications exist at the highest level. These are the tools that everyone who uses

Android is most familiar with. Android comes with various robust applications that

support everyday phone needs, such as messaging, e-mail, Internet browsing, and

various third-party applications. These applications are primarily written in the Java

programming language. In a recent legal case with Oracle, Google’s Android chief Andy

Rubin explained why he chose Java as the language of use for developers. Rubin’s primary

points were that Java had a well-known brand name and that Java is taught in almost all

universities worldwide.

These applications are distributed through various means, most commonly from

the Google Play Store (formerly Android Marketplace); however, the Android OS also

supports installation of applications over a USB connection and from an SD card.

Figure 1-1. The Android System Architecture

Android OS (Wikipedia) http://en.wikipedia.org/wiki/File:Android-System￾Architecture.svg

www.it-ebooks.info

CHAPTER 1 ■ History and Evolution of the Android OS

4

Application Frameworks

Android provides developers the ability and tools to create extensive, interactive, rich

graphical applications to users, and is targeted to deploy these applications to the

Google Play Store. Developers have access to the same APIs that are used inside of core

applications, as well as access to almost all existing Java libraries. For the development

process of Android applications, consult Chapter 6: Installing the Android SDK for Intel

Application Development.

Native Libraries

The next level is where the road diverges. The native libraries and the Android runtime

exist in roughly the same space. The native libraries are compiled and preinstalled

C/C++ binaries that the Android system depends on. These include all of the libraries in

the green section of Figure 1-1. The following sections contain descriptions of some of the

more prominent native libraries and their functions inside of Android.

Surface Manager

This is often referred to as Android’s Window Manager. Surface Manager is used for

composing what any individual screen will look like. It also does some more subtle things

that help Android run smoothly, such as off-screen buffering and transitions.

SQLite

This is a database used to persist information across sessions of an Android device. On

Android, the SQLite database is stored inside of the device’s internal memory so SD cards

can be interchanged without losing device-specific information.

WebKit

WebKit allows for HTML to be rendered and displayed to Android very quickly and

efficiently. This is the default browser engine in the Android system and is available to

system and third-party applications.

OpenGL/ES

The OpenGL engine processes graphics in Android. OpenGL can render both 2D and 3D

objects on Android. This also supports hardware acceleration on devices with dedicated

graphic chips.

Android Runtime

Inside of the Android runtime are two primary components: the core Java libraries that

Android provides, and the Dalvik virtual machine. The Dalvik virtual machine is Google’s

implementation of Java that is optimized to be used on mobile devices. The more specific

differences within Dalvik are very technical and aren’t covered in this book.

www.it-ebooks.info

CHAPTER 1 ■ History and Evolution of the Android OS

5

Linux Kernel

The last of the layers is the Linux kernel. Android was initially based on the Linux 2.6

kernel, with some optimizations for mobile use. Current versions of Android are based

on the Linux 3.1 kernel. The Linux kernel provides access as close to the hardware as

possible. As a result, drivers are written in the kernel space to operate as fast and as

efficiently as possible. These include things like controlling the internal radios, turning

on the stereo and camera, dealing with power and battery charging, and operating the

physical keyboard or buttons on the device. The Linux kernel, like Android, is an open

source project and is used widely, particularly on servers in enterprise environments.

The Open Handset Alliance

In November 2007, the Open Handset Alliance (OHA) was established by 34 founding

members dedicated to development of open mobile standards, including Google,

mobile device manufacturers, application developers, embedded systems developers,

and commercialization companies. The goal of this alliance as described in the web site

is as follows:

The Open Handset Alliance™, a group of 84 technology and mobile

companies who have come together to accelerate innovation in mobile and

offer consumers a richer, less expensive, and better mobile experience.

As it stands today, OHA has 84 firms who are developing and working on the

consortium’s main and only project to date, Android. Thanks to the services and products

offered by members of the OHA, devices and related services are produced at higher

quality for a lower price.

Android Open Source Project

After the purchase of Android, Inc., the Android Open Source Project (AOSP) was

created and has since been led by Google. The AOSP is in charge of the development and

maintenance of the Android software stack. As stated by Google, the goal of the project is

as follows:

The goal of the Android Open Source Project is to create a successful real￾world product that improves the mobile experience for end users.

Android is designed and maintained with backward capability in mind. This

means that new devices can run applications developed all the way back to Android’s

Cupcake (1.5). Official support for the Android SDK only goes back to Cupcake (1.5),

so applications written for pre-Cupcake devices aren’t guaranteed to run on the latest

Android devices.

Through the course of the AOSP, there have been many different versions of Android

released for mobile devices. When new Android versions are released, mobile device

www.it-ebooks.info

CHAPTER 1 ■ History and Evolution of the Android OS

6

owners are allowed to choose whether to upgrade their OS. With every iteration of

Android, a new SDK is made available to developers and various new features are added

to supported devices. Software developers need to stay mindful of the legacy features

from previous versions when developing new applications.

Astro (1.0)

Astro is where Android started, released as a beta in November 2007, and released to the

public in September of 2008 on the HTC Dream. Astro showed off various core features

of the Android OS and included many of the apps that Android users now know and love.

These include Android Market, a web browser, e-mail/Gmail, Google Maps, Messaging,

Media Player, YouTube, and various others.

Cupcake (1.5)

Cupcake, released April 30, 2009, was the next major version of Android to hit the

commercial markets. Cupcake was based on the Linux kernel 2.6.27 and included

many new features to users and developers. The major changes were support for virtual

keyboards, support for widgets on the home screen, animations added in various places,

and auto-pairing and stereo support for Bluetooth-capable devices. On a humorous side

note, from Cupcake and onward all Android versions to date have been named after

desserts.

Donut (1.6)

On September 15, 2009, Google released Android version 1.6, named Donut. With Donut

came an updated Linux kernel from 2.6.27 to 2.6.29, as well as some new features and

supported devices. Major features included voice and text search of contacts/web/

bookmarks, support for WVGA screens, and improvements to camera functionality and

speed. Donut was the last version of Android in the 1.x series to be released.

Éclair (2.0/2.1)

Éclair was released October 26, 2009, which continued to be built on the Linux kernel

version 2.6.29. With SDK version 2.0 came many new features and capabilities for

both developers and consumers. Large changes were made to the way that Android

looked and felt on capable devices, including significant speed improvements in many

different applications. The premier device for Android 2.0 was Motorola’s Droid on

Verizon Wireless.

On December 3, 2009, Google updated Android to version 2.0.1 in efforts to fix

some small bugs and update the API for developers. It wasn’t until January 12, 2010

that Android was moved to version 2.1. Similar to the update in December, version 2.1

primarily included updates to the underlying API and bug fixes.

www.it-ebooks.info

CHAPTER 1 ■ History and Evolution of the Android OS

7

Froyo (2.2.x)

On May 20, 2010, the Android SDK version 2.2 (Froyo) was released with Linux kernel

2.6.32. Google’s Nexus One was the first device on the market to show off Froyo and its

new capabilities. Very significant features were added to Froyo, including Adobe Flash

support, Android Cloud to Device Messaging, Wi-Fi hotspot functionality, and significant

performance optimizations. It’s important to note that the Android SDK recommends

choosing Froyo as your base development version to hit the largest current user base of

Android users.

Three subsequent updates were released for the Android 2.2 SDK: 2.2.1 on January

18, 2011, 2.2.2 on January 22, and 2.2.3 on November 21. These updates were primarily

bug fixes and security updates to Android.

Gingerbread (2.3.x)

Gingerbread was released on the December 6, 2010 and was based on the Linux kernel

2.6.35. Similar to the Froyo release, Google’s Nexus S was introduced to show off

Gingerbread. Features of Gingerbread include support for WXGA and other extra-large

screen sizes, improvements to the virtual keyboard, support for more internal sensors

(namely gyroscopes and barometers), support for multiple and front-facing cameras, and

the ability to read Near Field Communication (NFC) tags.

Five updates were released to Gingerbread, 2.3.3–7, from February to September

of 2011. With these updates came various features, security updates, and bug fixes. One

of the most significant features introduced was Open Accessory support, which lets a

compatible device function as an USB peripheral to compatible software platforms.

Honeycomb (3.x)

In February of 2011, Honeycomb, the first tablet-only Android version, was released on

the Motorola Xoom. Because Honeycomb was created specifically for tablet devices,

Android was tweaked to allow for a more enjoyable experience with larger screen real

estate. This included a redesign of the onscreen keyboard, a system bar to allow for quick

access to notifications and navigation, multiple browser tabs to allow for easier use of the

web, and support for multi-core processors.

Honeycomb has had six updates, two of which were major, through its current life

cycle. The first update was Android SDK version 3.1 on May 10, 2011, and it namely

added support for USB accessories such as keyboards, joysticks, and other human

interface devices (HIDs). The second major SDK update was 3.2 on July 15, 2011. The

most significant feature of 3.2 was compatibility display mode for Android applications

that were not designed for tablets. The last four updates to Honeycomb have been minor

improvements, bug fixes, and security updates.

Ice Cream Sandwich (4.0.x)

Ice Cream Sandwich (ICS) was released on October 19, 2011 and was based on the

Linux kernel 3.0.1. Samsung’s Galaxy Nexus was the device released with ICS as it hit

www.it-ebooks.info

CHAPTER 1 ■ History and Evolution of the Android OS

8

public markets. ICS was packed with a multitude of features and improvements to the

Android user interface (UI). Some features include a customizable launcher, a tabbed

web browser, facial recognition to unlock the device, a built-in photo editor, hardware

acceleration of the UI, and software buttons originally introduced in 3.x (Honeycomb).

It is important to note that ICS merged version 3.x (Honeycomb) and 2.3.x (Gingerbread)

into a single OS supporting both phones and tablets.

Four minor updates have since been released for ICS devices from November

of 2011 to March of 2012. These updates focused on stability improvements, camera

performance, and bug fixes.

Jelly Bean (4.1.x)

Jelly Bean was released on July 9, 2012 and is based on the Linux kernel 3.1.10. Asus’

Nexus 7 tablet device was the flagship user of Jelly Bean. Jelly Bean released a number of

improvements and performance upgrades to the UI and audio within Android. Version

4.2, released on November 13, 2012 and based on Linux kernel 3.4.0, added accessibility

improvements. Version 4.3 was released on July 24, 2013, and added OpenGL ES 3.0

support for better game graphics, security enhancements, and upgraded digital rights

management APIs. Other features of the Jelly Bean versions include customizable

keyboard layouts, expandable notifications, application-specific notification filtering, and

multichannel audio.

KitKat (4.4.x)

The last version of Android as of this writing, KitKat, was released on September 3, 2013.

Its features included performance optimizations for devices with less RAM, expanded

accessibility APIs, wireless printing capability, and a new experimental runtime virtual

machine, called ART, which may come to replace Dalvik. KitKat debuted on Google’s own

Nexus 5 smartphone on October 31. 2013.

Overview

With all of these versions of Android, the features and changes to the OS have led to a rich

and user-centered experience. The average user, who knows little to nothing about the

technical aspects of the device, can operate the device like it is second nature. Now that

you have acquired more insight into the underlying systems and architectures that make

this possible, the only thing left to ask is, what’s next?

www.it-ebooks.info