Raspberry Pi Android InstallationLinux User & Developer Magazine Issue 1202012

7/22/2019 Raspberry Pi Android InstallationLinux User & Developer Magazine Issue 1202012

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www.linuxuser.co.uk

8 PAGESPECIALRASPBERRY PI

FOR THE GNU GENERATIONTHE MONTHLY MAGAZINE

9 77 20 41 327 002

2 0

ISSUE 120 5.99

Build a smart TV Automate your homeRun Android appsMake a car-puter

ALSO INSIDEGNOME 3.6: our verdict

Create a network of RasPisWhat happened to GNU Hurd?Improve workflow with login scripts

Master Emacsake control with the Swissrmy chainsaw of FOSS

PyCon 2012Catch up with thehottest events

20 pages of reviewsDefinitive opinion ondevices, distros and apps

AndroidRaspberry PiInstall

on your

Make GNOME extensionsAdd new features andfunctionality to GNOME 3

Ultimate office

suite revealed!The best open sourcealternatives to MS Office

$99 SupercomputerAdaptevas founderintroduces us to the

of expertadvice30+pages


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W o r l d M a g s . n e t W o r l d M a g s . n e t

W o r l d M a g s . n e t
http://worldmags.net/http://worldmags.net/http://worldmags.net/


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Gareth Halfacree has been breaking, fixing,tinkering and voiding warrantieson electrical items for manyyears, without once receiving afatal electric shock. This monthGareth brings us the story of the$99 supercomputer (pages 48-51)and reviews the latest release innetwork-attached storage.

Joey Bernard is a true renaissance man,

splitting his time between buildingfurniture, helping researchers withscientific computing problemsand writing Android apps (whenthe kids let him have some time).This month Joey serves up twotutorials on server monitoring andEmacs, on pages 30-33 and 38-41.

Kunal Deo is a veteran open source developerleading multiple open sourceprojects. He is also a KDE dev andhas contributed to many projectsincluding KDE-Solaris, Belenixand Openmoko. In this issue Kunaldemonstrates how to build GNOMEShell extensions in his step-by-step tutorial on pages 52-55.

Jon Masters is a Linux kernel hacker who hasbeen working on Linux for almost17 years, since he first attendeduniversity at the age of 13. Jon livesin Massachusetts and works for alarge enterprise Linux vendor. Aswell as running kernelpodcast.orghe keeps us up to date on the Linuxkernel with his column on page 12.

Liam Fraser is the creator of theRaspberryPiTutorials YouTubeseries and is a Linux serveradministrator of the RaspberryPi Foundation. This month Liamshows us how to build a networkof Raspberry Pis with centralisedstorage. You can find his article

starting on page 56.

Rob Zwetsloot studied aerospace engineeringat university, using Python tomodel complex simulations andconfiguring Linux HTPCs. This issueRob reminds us why LibreOfficeis the greatest office suite in opensource (pages 70-74) and showsus how to install Android on theRaspberry Pi in our cover feature.

Issue 1203

Yourtea

mofLinuxex

perts

Get in touch with the team:[email protected]

Welcometo issue 120 of Linux User & Developer

Welcome to the latest edition of Linux User & Developer,the UK and Americas favourite high-end open sourceand Linux magazine.

The clocks have gone back and Christmas is fastapproaching. While weve got some special treats lined upto mark our final issue of 2012 next month, weve workedparticularly hard this issue to ensure youve got plenty of

projects to keep you out of trouble as the evenings draw in.The Raspberry Pi owners among you are in particular luck weve

got an eight-page special looking at how to get Android up andrunning, starting on page 22. While theres still plenty of work to doto get the drivers working smoothly with 3D and media applications,Android opens up a whole world of new possibilities for your $35computer and we cant wait to see what the community does with itover the coming months.

If youre feeling particularly adventurous you could join JoeyBernard over on page 38 as he uses Emacs to create to-do lists. Ifyouve never dabbled with Emacs before, youll probably want to dosome extracurricular homework first even the keyboard shortcutscan be demanding to the uninitiated.

Finally a quick mention to Parabella, a Kickstarter project thatscome to be known as the $99 supercomputer. Check out ourinterview with its creator starting on page 48 it looks like theRaspberry Pi might have some serious competition

Russell Barnes,Editor

Buy online

GetLinux User

for 4.19per issue

Page 20

Install Android on RasPiBuild GNOME extensionsMonitor your home serverOrganise yourself with Emacs

This issue

Visit us online for more news, opinion, tutorials and reviews:

www.linuxuser.co.ukW o r l d M a g s . n e t W o r l d M a g s . n e t

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Contents

Join us online for more Linux news, opinion and reviewswww.linuxuser.co.uk

www.linuxuser.co.uk4

06 News The biggest stories from the

open source world

12 OpinionsThe latest from our regularfree software columnists

94 Letters Your views on the magazine

and the open source scene

OpenSource

96Cover disc Test four of the latest distros:

On your free disc

Ubuntu 12.10, Kubuntu

Xubuntu

Lubuntu

Tutorials30 Monitor your server with tmux Remotely check your server in easy steps

34 Create and manage boot scriptsand startup applications

Automate your startup experience

38 Make an open source to-do listwith Emacs

Use Emacs to organise your workflow andtake control of your time

Developer tutorialsFeatures16 Get on board

with PythonReporting back from PyCon

22 Install Android onthe Raspberry Pi

A world of new possibilities

42 Wheres the Hurd? We investigate the true

kernel of the GNU OS

48 Supercomputing forthe massesWe talk to Andreas Olofssonabout Parallella

70 Office suite super-testFour of the best in opensource go head-to-head

86 Q & AYour problems solved!

FEATU

RE

16Get on board with PythonLinux Users Richard Smedley reports backfrom this years PyConUK event. Catch upon all the action and learn why Pythons

community is one of the best there is.

52 Build extensions for the GNOMEdesktop environmentExploring GNOME 3s best new capability

56 Create a network ofRaspberry Pis

Bring several Pis together on a network

with centralised storage and more

Reviews

Open up a world of newapps and projects in

just a few easy steps

22Install Android onthe Raspberry Pi

62 Samsung GalaxyNote 10.1

The Note migrates to the tabletform factor in fine style

64 Synology DS213airSynologys latest small andhome office NAS box

66 Archos 101XS

Archos adds keys to itslatest tablet

68 GNOME 3.6 GNOME moves further down

the path of simplification

70 Office suite group test Four of the very best open

source suites battle it out

76 CAINE 3.0 We rate the latest build of this

penetration-testing distro

78 Ubuntu 12.10 We score Canonical on Ubuntus

new (and controversial) features

80Fractal DesignDefine R4The perfect home server case?

82 GNOME Shell Remix Ubuntu with GNOME 3 Shell

Subscribetoday!

20 Save at least 30%on the shop price.US customerscan subscribe viapage 83




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06News | 12Opinion | 94Online

Samsung has announced another entry in

its Chromebook partnership with Google,

making the move away from x86-based

Intel processors with an ARM-based ultra-

compact device aimed at buyers on a budget

or, as Google itself would have it, a computer

for everyone.Based on Samsungs existing Chromebook

platform a cut-price family of low-power

laptops which use Googles Chrome OS, based

on the open source Chromium Linux cloud-

powered operating system the new Samsung

Chromebook replaces the typical lightweight

x86 Intel chip with a dual-core Exynos V ARM-

based processor, a quad-core version of which

can be found in Samsungs flagship Galaxy S III

Android smartphone.

Running at 1.7GHz, the chip includes a

quad-core ARM Mali-T604 graphics processor

which handles both the HDMI

display connector


is not

p r o v i d e d

to the public

under an open

source licence.

Much of the code,

however, is: ChromeOS itself is based on the open

source Chromium OS, while the embedded

Chrome browser is available as the open source

Chromium project.

For consumers, the cut-price Chromebook

could well be an entry point into Linux as a day-

to-day operating system. For those who know

their way around a shell already, the presence

of a development mode accessed by holding

Esc, Refresh and Power then pressing Ctrl+D

at the boot screen provides a way to boot from

external devices, replace the operating system

and turn the Chromebook into a low-cost ARM-

based laptop running almost any Linux-based

operating system.

Google, meanwhile, is positioning the

Samsung Chromebook as the answer to

Windows users prayers. Theres no need to

worry about security updates and maintenance

is easy; all you need to do is charge the battery,

boasted Googles Sundar Pichal, senior vice

president of the companys Chrome division at

the launch. It just works.

Without a Linux kernel at the new machines

heart, its unlikely Pichal would have been able

to make such a declaration.

The new Samsung Chromebook is available

through Google Play, Currys and PC World,

priced at 229.

Entry-level Linux-based laptop takesaim at the mass market

HARDWARE

Google &Samsung

launch ARMChromebook The Samsung-manufactured Chromebookuses an Exynos V ARM-

based processor and runs

the Linux-based Chrome OS

and the integrated 11.6-inch 1366x768 display.

Storage is handled by an eMMC 16GB solid-

state storage device helping the Chromebook

hit a headline-grabbing sub-10-second boot

time while 2GB of DDR3 memory is included

as standard.

A switch to an ARM processor morecommonly found inside smartphones provides

the Chromebook with impressive battery life,

with around six hours easily available during

web-connected usage. More importantly, the

use of web apps in Chrome OS which are

rendered through an embedded version of

Googles Chrome web browser avoids any

compatibility issues with legacy apps that

normally accompany a shift in architecture.

The specifications aside, Googles positioning

of the device as a computer for everyone is

interesting indeed. As well as selling the system

through the Google Play marketplace alongside

its Nexus 7 Android tablets, the company

has organised high-street placement for the

Chromebook in major chains throughout the

world and just in time for Christmas.

In other words, a major brand

is attempting to put Linux

on the laps of millions and

where Google leads, others

are likely to follow.

Detractors of the

Chromebook project often

point out that its not a truly

open platform: like Android,

Google develops Chrome OS

privately and often

includes code which




7/100

The latest in the Linux community

News

OPEN SOURCE

www.linuxuser.co.uk7 www.linuxuser.co.uk7

Linuxcalendar

29Nov2012

Android Magazine issue 19www.littlegreenrobot.co.ukAndroid Magazine, your best andonly print source for everythingAndroid, is coming out today. Checkout whats in store over on page 60.

CloudStackCollaboration

ConferenceThe Venetian, Las Vegas, Nevada

USA

http://collab12.cloudstack.org/The Apache-run conference willhave presentations from thedevelopers contributing to theApache CloudStack project, as welladmins who are using CloudStackto build clouds to scale.

30Nov-02Dec2012

Users testing the cutting-edge

build of Firefox for Android,

from the Aurora branch, are

now able to access Mozillas

Firefox Marketplace. Designed

as an answer to Googles Chrome

Store, the Firefox Marketplace

provides free and paid-for

web apps which are designed

specifically for the open source

Firefox browser.

While users have been able to

test the Marketplace on desktop

Firefox releases for some time,

the addition of support in the

Aurora Firefox for Android build

marks the first time it has been

available on mobile devices.

Sadly, the service is still closed

off from some: Mozillas decision

to focus exclusively on developing

for the ARM architecture means

Firefox for Android cant be

installed on devices with Intels

x86-based Atom processor, like

the Motorola Razr i smartphone.

The Aurora build of Firefox is at:

www.mozilla.org/mobile/aurora .

Canonical founder Mark Shuttleworth has

announced that selected aspects of Ubuntu

13.04, codenamed Raring Ringtail, are to

be developed in secret so as not to attract

criticism from the community.

Going against the open source ethos of

transparent development, some new featuresto be launched with Ubuntu 13.04 will be kept

under wraps at Canonicals HQ until the OS is

ready for release a move which appears to

have much to do with community backlash

over the switch to the Canonical-developed

Unity desktop environment and the numerous

glitches and bugs that followed.

Described by Shuttleworth as a few items

with high tada! value, the precise portions of

the OS which will be hidden until launch have

not been detailed. Those who are interested can

apply for access, however, with Shuttleworth

claiming that Canonical is happy to engage with

contributing community members that have

established credibility in Ubuntu.

The skunkworks approach has its

detractors, Shuttleworth admitted in astatement to the community. Weve tried it both

ways and, in the end, figured out that critics

will be critics whether you discuss an idea with

them in advance or not. Working on something

in a way that lets you refine it till it feels ready

to go has advantages: you can take time to

craft something, you can be judged when youre

ready, you get a lot more punch when you tell

your story, and you get your name in lights.

The secretive projects, which Shuttleworth

claims are all groundbreaking in free

software, cover areas such as web standards,

cryptography, and aesthetic and performance

improvements, with Canonical keeping eachunder close guard until launch and inviting only

pre-vetted members of the Ubuntu community

to help with their development. With Canonical

already under the spotlight for what is seen

as an increasingly negligent attitude to its

community of users and developers, and to the

open source community in general, this latest

announcement is likely to do little to cool the

flames gathering against the company.

OPEN SOURCE

Canonical hides Ubuntu 13.04development from the community

LISA 12 Sheraton San Diego Hotel and

Marina, San Diego, California

USA

h t t p s : / / w w w . u s e n i x . o r g / conference/lisa12In addition to the wide varietyof topics covered in the LISA 12programme, the programme

committee has created threespecific conference themes, ortracks, for those looking to focuson a key subject; these cover theareas of cloud computing, IPv6 andsysadmin skills.

09-14Dec2012

Shuttleworth blames critics for new secretive strategy

Marketplace is now

available on Android,

providing a new route

for installing web apps

ANDROID

Mozilla opens Firefox

Marketplace on Android

Mark Shuttleworth, seen here on board the

International Space Station, is hiding some

parts of Ubuntu 13.04 from the community




8/100

INDUSTRY

Your source of Linux news and viewsOpenSourceContact usRegister and post your commentswww.linuxuser.co.uk/forum/

Email us [email protected]

Windows 8 harms user freedomThe launch of Windows 8 occurred very

recently Microsofts new, one-size-fits-

all operating system for desktop, tablets,

and smartphones. Thanks to the Interface

Formerly Known As Metro, the folks at

Redmond plan to claw back their market sharein the PC space by finally cracking the portable

computing market. Or at least, thats the idea.

Microsoft is going through the same motions

that Canonical and GNOME have done in recent

years, trying to convince people that their

interfaces are fine for mouse and keyboard

even when the results seem to contradict this.

On the day of launch, Jim Zemlin, executive

director of the Linux Foundation, wrote a blog

on how Windows 8s hybrid approach is too

little too late:

A lot has changed in the three years since

the last major Windows announcement.

Netbooks were on the rise. The iPad wouldntbe introduced for another six months and

Nokia still had the lead for most smartphone

sales in the world that is no longer the case.

Googles Android OS only accounted for a

3.9% share of the smartphone market in 2009

(according to Gartner Group);

last year that rose to 64%

of the smartphone

market. In 2011,

smartphones for the

first time outsold PCs

(including tablets). With

hundreds of millions

of those smartphones

running Android, the

consumer market is

fully accustomed to Linux-

based software.

Zemlin argues that

we are living

s o m e w h a t

in a post-

desktop

wo r l d ,

or at

least


The recent release of Windows 8 has causedconcern for the leaders of the free software world

its basically Windows 7 with new surveillance

features and even more restrictions on users

freedom. Whether or not Microsoft wants you

to know it, its easy to switch to free software

instead of choosing a downgrade to your rights

as a computer user for example, your rights to

know what the system is doing and to change

behaviours you dont like. Were here because

we want people to know that they dont have to

buy Windows 8 this is a great time to upgrade

to free as in freedom software.

Libby Reinish says that Windows 8 cuts

down on user freedom

well into a transition period, and Linux is

helping to drive this as the base for Android and

Chrome OS.

Microsoft is stuck in the liminal space

between the desktop-driven, cost-per-

software licence world they dominated and

the era we are just now entering: a world

driven by open source software and services,

continued Zemlin, pointing out that the price of

Microsoft hardware is up to six times more than

hardware powered by Linux. He attributes this

to companies like Google not having to spend

so much on R&D, with the Linux kernel and its

estimated $10 billion (6.2 billion) worth of

development readily available, along with FOSS

such as WebKit.

The Free Software Foundation agrees with

this, and activists set out on the morning of

release to New Yorks Microsoft store to hand

out pamphlets to the people braving the cold

to attend the launch event. In it, they warned of

the dangers of proprietary software:

Microsoft has already spent almost 2 billion

dollars on slick advertisements to convince

people that Windows 8 will revolutionise the

way they use computers, said Libby Reinish,

campaigns manager at the FSF. The fact is,

The gnu is a symbolof software freedom

Jim Zemlin believes that

mobile computing is the future

CC:www.fsf.org

CC:www.fsf.org




9/100

The latest in the Linux communityNews

OPEN SOURCE

Imagine Publishings All About Space

magazine is available in print and digital

formats right now. Packed full of cosmic

content, All About Space delves into the

wonders of space exploration, astronomy

and space science every month, providing in-

depth knowledge from a team of experts on

an amazing array of topics. The magazine isunlike anything else out there and will appeal to

seasoned space fans and new explorers alike,

with a regular dose of amazing articles, exclusive

interviews and jaw-dropping images.

Inside youll find some mind-blowing articles

and features explaining the amazing universe

around us. The latest issue reveals how some of

the biggest explosions in the universe, namely

All About Space, the most excitingspace magazine ever, is out now!

PUBLISHING

supernovas, work. There are also excellent

articles on tracking hazardous asteroids, the

first moonwalk, NASAs first space station, the

groundbreaking Cassini mission and much

more. All About Space also makes astronomy

accessible to everyone with a host of stargazing

articles explaining how to buy a telescope and

what to look for in the night sky.All About Space is available online at the

Imagine eShop (www.imagineshop.co.uk)

and in all good newsagents and supermarkets

right now. You can also download the digital

version for iPhone, iPad and Android from

www.greatdigitalmagazines.com. Visit the

magazines website at www.spaceanswers.com

to get your online space fix.

Unsure what to get sysadmins, codersor FOSS advocates this Christmas? Wemight have an idea for youIts only a month until Christmas now, and while the more organised

folks may have already got gifts for all their family, friends and

secret Santas, the rest of us have probably been a bit too busy to

even figure out whos getting gifts. Well, Linux User is here to give

you a helping hand as were offering 10% off on all orders from the

ImagineShop until 24 December 2012.

This offer is valid on subscriptions to the magazine,

back issues of Linux User, bookazines such as

the Linux & Open Source Genius Guide Vol. 2,

and DVDs from Web Designer. There are

further discounts available on all of these

that you can find out about on page 75. You

should also keep an eye on our Twitter feed

we regularly tweet out links for fantastic

subscription deals that you can redeem on the

ImagineShop, such as getting the first three

magazines in a subscription for 1 each.

So if youre scrambling for a present

to give to a tech friend or colleague,

you can sit back and get them

some magazines from the

comfort of your desk chair,

and properly enjoy the

holiday season.

In case you missed it, Linux User magazine is

available to read on any digital format thanks

to the excellent digital editions super-site,

www.greatdigitalmags.com. The site

brings together Linux Users offerings

on Zinio and Newsstand, allowing you to

enjoy your favourite mag on your Mac, PC,

iPad, Android and a host of other devices.

There are some incredible subscriptionincentives up for grabs too, not just for Linux

User but for all Imagine Publishing titles.

To find these amazing deals, head over to

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PUBLISHINGGrab LinuxUser digitally atgreatdigitalmags.com

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10/100

Your source of Linux news and viewsOpenSourceContact usRegister and post your commentswww.linuxuser.co.uk/forum/

Email us [email protected]


There have been plenty of valid concerns

regarding the future of computing with regard to

UEFI Secure Boot, mainly with how it will lock out

people wanting to install a Linux distribution.The

Linux Foundation has been following the situation

and has decided to take action by purchasing

a key from Microsoft, and signing its own smallpre-bootloader that will be available to all users of

open source. The Linux Foundation explained the

reasoning behind this move in a blog post:

The Linux Foundation is committed to giving

users freedom of choice on their platforms.

Conforming to this stance, we have already

published a variety of tools to permit users to

take control of their secure boot platforms by

replacing the Platform Key and managing (or

replacing) the installed Key Exchange Keys

however, as one of the enablers of the Linux

ecosystem, the Foundation recognises that not

everyone is willing (or able) to do this, so it was

also necessary to find a solution that would

enable people to continue to try out Linux and

other open source operating systems in spite of

the barriers UEFI Secure Boot would place in their

way and without requiring that they understandhow to take control of their platforms. Therefore,

we also formulated a technical plan, which is

implemented in this pre-bootloader, to allow

distributions to continue functioning in a secure

boot environment.

The source code for the pre-bootloader is

available at the moment without the key, and you

can get it from the Git repo as Loader.c. The Linux

Foundation admits that it will take a little time for

the key and signature to be obtained, but it will

announce when it receives one.

Foundation takes action to ensure everybody can continueusing open source operating systems

OPEN SOURCE

The Linux Foundation obtains UEFI key

Ubuntu is a free operating system, free as in

speech and as in beer, and Canonical is keen

to reinforce this Richard Stallman ethos as it

announces a new way for users to optionally

contribute to Canonical before they download

the desktop version of Ubuntu.This comes in

the form of real money donations.

Its not just a fixed donation there are

eight categories that people can selectively

give money to. This will let Canonical know

which parts of Ubuntu people want improved.

Categories include Unity, performance

optimisation, hardware support, phone and

tablet versions, support of different Ubuntu

flavours, and a general tip to Canonical. You

dont have to give to each category, though,

and donations start at $1 per category.

Obviously you dont have to make any

contributions if you dont want to although

Users can now tell Canonicalwhat parts of Ubuntu needwork, for a price

Now that Ubuntu 12.10 is out and more

people will be downloading the distro, it will be

interesting to see what contributions are made,

and what they go towards. You can see the

page by selecting Ubuntu Desktop (and then a

version) at: www.ubuntu.com/download.

A screen Ubuntu users may have to get used to

The Linux Foundations goal is to

promote and protect the Linux kernel

The future

of firmware

interfaces is closed

the donation page shows up before you can

download the ISO, and has a recommended

$2 donation to each category already filled in

by default. Theres a link at the bottom of the

page to skip it entirely and go straight to the

download page.

OPEN SOURCE

Donate to Canonicaland steer Ubuntu




11/100

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12/100


Your source of Linux news and viewsOpenSource

Jon Masters summarises the latest goings-on inthe Linux kernel community, including a look at the

features being merged for the upcoming 3.7 release

Jon MastersTHE KERNEL COLUMN

Linus Torvalds announced the release of

the 3.6 kernel, saying that while the release

did not contain earth-shattering new

architectures or file systems, it did overall

represent solid progress. We summarised

some of the new features that landed in Linux

3.6 last issue. With the release of 3.6 came

the traditional opening of the merge window

for 3.7. This is the period of time during which

Linus is willing to pull potentially disruptive

patches (changes) into the kernel. This typically

lasts for two weeks and is followed by a period

of stabilisation, and multiple RC (release

candidate) kernels are made available for

testing. Linus gave a heads-up that he would

be travelling for much of the merge window, but

that didnt seem to pose much of a problem.

Features pulled in during the merge window

included a brand new architecture (AArch64,

also known as ARMv8 or arm64 in the kernel

community). This is the latest architecture

revision from ARM, the company that powers

about 90 per cent of all cellphones and has had

its designs shipped in billions of processors

so far this year alone. ARM has traditionally

been an embedded architecture. The billions

of ARM-powered processors in use worldwide

are typically found within gadgets, such as

this authors fitbit personal step counter, or in

washing machines and automotive control and

entertainment systems. In this context, there

are many different levels of ARM processor,

from the more deeply embedded simpler cores

without the ability to run a full OS, to higher-

end multiprocessor cores running Linux on

Android smartphones.

ARM is known for its focus on low energy, as

well as the licensed nature of the architecture.

ARM doesnt make processors it licenses its

designs for use by the many others who do makeprocessors. Linux has run on suitable 32-bit

ARM-based systems for well over a decade,

and in recent years has gained popularity

as the foundation upon which most Android

devices are built. And over the last few years,

organisations such as Linaro have helped to

drive the development of Linux support for

ARM by bringing together a wider community

of companies and ecosystem players involved.

Over the past few years, a new opportunity has

emerged to take advantage of the low-energy

DNA that drives ARM by using these processors

in server-class systems.

Servers can be 32-bit based, but many

workloads require 64-bit support. Thats where

the new AArch64 ARM architecture comes in.

It brings many new features to ARM, not least

of which is 64-bit addressing. The new support

within the Linux kernel, contained within

arch/arm64 (renamed after community debate

around the original aarch64 choice of directory)

enables the core architecture features but does

not yet have support for any real processors.

Those will come later. The initial support was

merged after several months of review on

the Linux Kernel Mailing List by upstream

maintainers such as Arnd Bergmann, who is

responsible for many of the de facto standards

required of new architecture code added to Linux.

Jon Masters is aLinux kernel hacker whohas been working onLinux for almost 17 years,since he first attendeduniversity at the age of 13.Jon lives in Cambridge,Massachusetts, and worksfor a large enterprise Linuxvendor. He publishesa daily Linux kernelmailing list summary atkernelpodcast.org




13/100


The kernel column Jon MastersOpinion

OPEN SOURCE

Another feature pulled into Linux 3.7 is

support for the supervisor mode access

prevention on Intel processors. This aims

to prevent kernel code from being able to

compromise the running system, even if it is

exploited by passing bad values in from user

space (such as were done by various example

NULL pointer kernel exploits several years

ago). By toggling a special bit in the CPU control

registers, the kernel can effectively instruct the

hardware to prevent the kernel from accessing

user space (regular user process) memory

except under explicit control. Therefore various

classes of exploit are removed because eventhough the kernel has the power to disable

the protection again, a simple pointer access

to user space cannot simultaneously disable

the SMAP protection, so exploit code has no

straightforward way to use such simple attacks.

One final feature of particular note in 3.7 is the

removal of udev from the critical path of loading

some system firmware. The kernels built-in

firmware loader will now always attempt to load

firmware files directly from user space (from

the file system) without invoking udev. Udev

(the user-space device management daemon)

typically handles firmware loading, as well

as device driver requests, and new hardwaredevice detection, by receiving messages from

the kernel over a special netlink socket and

reacting according to various customisable

rules. Unfortunately, recent changes to udev to

restructure its approach to parallelised loading

of drivers frustrated Linus into having the kernel

handle this itself by default. Udev can still

handle firmware loading, but the kernel will first

attempt to load files itself, from /lib/firmware.

Alignment faults in 3.6Linux supports many different architectures,

some of which behave quite differently from

the x86 Linus originally used way back in 1991.

In particular, many modern RISC architectures

embrace the notion of simple being better by

having limited support for misaligned memory

accesses. On these architectures (such as

ARM), it is not possible to directly perform an

operation on a memory location. Instead, the

architecture behaves in a load store fashion

such that all memory locations must be loaded

into a register, then manipulated, then the

result stored back.

Alignment is a natural property of all data

types. A 4-byte integer value, the default on

many systems, has a natural alignment on a

4-byte memory boundary. So, for example,

attempting to load or store such a value atan odd-numbered memory address would

be in clear violation of the natural alignment

requirement of this type. Many modern

architectures hide such alignment issues by

having the hardware perform expensive multi-

load operations behind the scenes under such

circumstances, while others will generate an

alignment fault and insist that the programmer

(or the compiler) do the right thing and fix the

underlying code. ARM is one such architecture

that started life with very strict requirements,

and has relaxed more recently.

Modern ARM systems do include (limited)

support for unaligned data access. Though they

are more expensive (in terms of performance

overhead), they are handled behind the scenes.

There are some circumstances under which this

is not possible due to specific instructions being

used. In such cases, the hardware will generate

an alignment fault, which will be handled by

the kernel. The kernel typically performs a

more expensive version of the intended load

or store transparently, optionally recording a

warning about the inefficient waste of processor

Linus said he would be travelling

for much of the merge window

resources. During this operation, it may make a

call to the kernels schedule() algorithm to give

another process time to run. Unfortunately,

there are some situations wherein the scheduler

must not be called. These include certain criticalatomic parts of the kernel itself. In the case

of Linux 3.6, it appeared as if this required was

being violated, with warnings of scheduling

while atomic being emitted.

It ultimately turned out that certain device

drivers were exposing a problem in the

alignment handler. By accessing misaligned IP

header fragments, the driver concerned was

triggering an alignment exception within an

atomic-critical section of kernel code, which

was then resulting in the scheduler being

called from within the alignment handler.

Although the driver was later fixed to improve

performance (by using only aligned data), the

problem with the alignment handler itself did

require fixing to prevent unwanted system

crashes. A patch has been successfully tested

and will be merged.

Finally this month, there has been an

ongoing discussion around ext4 file system

corruption that can occur under very specific

circumstances involving a system crash during

an update to an ext4 file system running with

journal checksums turned on. This is not the

default, and it is a rare situation, but all users are

advised to update their systems.

nLinus

Torvalds:

the 3.6 kernel

is solid

progress

CC

.GFDL

.Perm

iss

iono

fMar

tin

Stre

icher,

Editor-

in-

Chief,LINUXMAG

.com




14/100

THE OPEN SOURCE COLUMN


Your source of Linux news and viewsOpenSource

Apples latest product launch wasmet with disdain from many of itscustomers. But why, wonders Simon

Throwing awayan iPad

Simon Brew is a technologywriter and editor,working across theLinux, Windows andMac OS X platforms

Watching the live reactions to an Apple

announcement rarely tends to expose you to

some of the more considered thoughts on a

product launch. Yet the response to Apples

unveiling on 23 October of a pair of new iPad

products was a testament to just how warped

the technology business has become.

Appreciating its traditional to bash Apple at

every opportunity, I find myself admiring the firmin some ways. Granted, its closed gate approach

to computing is something that continually

needs fighting, but its marriage of software and

hardware remains pretty much unparalleled

over the past decade or so.

At Apples event in October, though, it sprung

a surprise. It had widely been expected that the

firm would showcase the iPad mini, and thats

exactly what it did. But then it had something

else up its sleeve: a fourth generation of the

iPad. This was just over half a year after it had

launched the third generation of the iPad to

similar fanfare. And people were not happy.

To paraphrase what, at one stage, was

appearing to be something of a consensus,

the feeling seemed to be but I only bought one

of those half a year ago, and now theyve gone

and changed.

So lets think about that for a second.

What Apple has successfully propagated is a

feeling among its customers and many in the

technology world that you absolutely have to

have the latest and greatest. Notwithstanding

the fact that the original iPad is still doing the

job that it was designed for perfectly well,

there appears to be abject horror in places at

the thought that people will have to upgrade a

product that was only new on the shelves earlier

in the year.

The mini wasnt the only new iPad launched

The Androidfightback?

But where did this craving come from? What

new feature does the fourth-generation iPad

possess that the third didnt, that people cant

possibly live without? Within minutes of the

announcement, eBay was no doubt filling up

with pretty much brand spanking new iPads,

as the disposal culture of modern technology

continues to take hold.

That in itself is a burgeoning problem. Firmslike Apple like to lock us out of upgrading

products, and even the likes of HTC is now

making phones where youre not even allowed to

change the battery yourself (when did we start

to accept this insanity as the norm, I continue

to wonder). The ramification of this, longer term,

is that more and more people will just throw

something away after a year, in order to get the

latest model. People will change their phone just

because its less hassle than sending it off to get

a new battery put in. Thats madness, isnt it?

What Apples announcement showed is that

you dont actually need to add that much for

people to instantly decide to spend another

500 or so on another piece of technology, just

to keep up with the proverbial Joneses. Wouldnt

it be refreshing, though, if a firm such as Apple,

that has so blazed the trail for persuading

people to replace their technology on an annual

basis, actually made a stand to say enough is

enough. Itll never happen, but just how long

can the world at large support a culture where

intricate technologies are so disposable?

Looking at the reaction to the aforementioned

Apple launch, its going to have to do so for a

great deal longer, sadly

In the smartphone sector, Android continuesto lead the way over Apple and its iOS-basedproducts. In tablets, its success has beenless significant, but might there now be signsthat Android-based competitors are makinginroads? Certainly products like the Nexus 7and to a lesser extent the Kindle Fire help.But theres a long way to go to topple Appleand its all-conquering (so far) iPad.




15/100


The free software columnOpinion

OPEN SOURCE

THE FREE SOFTWARE COLUMN

As everybody knows by now, the Raspberry

Pi is the perfect geek toy, a credit-card-sizedcomputer that costs very little and comes with

its own operating system, Raspbian, which is

an optimised reworking of Debian GNU/Linux.

The Raspberry Pi can be plugged into a TV and

a keyboard, and will do most of the useful things

a PC can do. An SD card is used for booting and

storage of data. Raspbian defaults to an LXDE

desktop, and comes with development tools

and most of the basic applications and utilities

for working and playing on a computer. The

Raspberry Pi is also shockingly cheap $35.

But the interesting part of the Raspberry Pi

is the ambition of its caretakers that it should

become an ultra-low-cost tool for introducingschoolchildren to the lost idea that computer

programming can be fun, as it was for the kids

who grew up with the Sinclair QL, ZX Spectrum

or BBC Micro three of four decades ago. The

early home computers were cheap and cheerful,

but you could get inside and look at the source,

take them apart and learn.

Some of the kids who grew up with BBC Basic,

Dungeons & Dragons and Pac-Man became the

first generation of developers to work on Linux

and other free software. Jeremy Allison, for

instance, had a Sinclair QL, which was a 32-bit

The Raspberry Pi can be the affordable routeto teaching schoolchildren the lost idea thatcomputer programming can be fun

Raspberry Pi for schools

machine, even though it had an 8-bit bus. The

source code of the operating system, QDOS, wasincluded, perfectly legally.

The assembler source, the commented

source, you could buy and look at, and take

apart and understand, says Allison. It was

burnt into ROM, but you could modify it there

was a company that had disassembled it for me,

legally and then along came the IBM PC and

Microsoft and crushed all the creativity out of it,

just ground over it with a tank tread.

So the kids growing up these days dont know

any of that stuff. They dont know the basics of

how the thing works. Theyve got black boxes

that rattle because theyre broken, and they

cant look inside. You cant learn from that.I want anyone in the world to have the

same opportunities that I had when I was

growing up, adds Allison. The early Eighties

was a period of intense creativity in the

computer industry in Britain.

But ICT in schools went backwards in the UK

and has been locked in to a costly Microsoft-

only world, where children have been educated

as users rather than doers. Lock-in and the

upgrade cycle have resulted in the same

escalating costs that have afflicted other

sectors of the IT industry, forcing increased

expenditure for smaller and smaller returns.

For most children, ICT in schools has been

little more than a training programme for

using Windows and Microsoft Office useful

for secretaries and filing clerks, but not

helpful for getting to know how the technology

works. A common complaint has been that no

ICT course has a programming or a systems

module, instead students are taught to be

mere consumers of technology, and operators

of applications.

Programming can be fun, and the principles

are easy to learn. The Raspberry Pi can be the

affordable route to learning this lesson.

Richard Hillesley writes aboutart, music, digital rights,

Linux and free software fora variety of publications

nProgramming can be

fun and easy to learn for

schoolchildren, and the

ultra-low-cost Raspberry Piis an ideal tool for teaching




16/100


Despite masterpieces of medieval and 20th Century

architecture, and a fascinating industrial heritage,

Coventry isnt everyones ideal long weekend getaway. That

changed for the last four days of September, when the city

hosted PyConUK the annual gathering of the countrys

enthusiastic and growing Python community for the

second time.

Regular readers will know that, while LUD maintains

an even-handed approach to open source languages and

technologies, we find ourselves reporting a lot of cool Python

projects, and its increasingly the language of choice for

everything from education and banking to research and big

data. Many programming languages have a strong community

around their use, but Pythonistas seem to have a sense of

belonging as if theyve somehow, in finding Python, come

home that is normally reserved for Lisp programmers, and all

without the smugness occasionally seen in the latter group.

This is a confident community, and one not without a sense

of humour as you would expect from a language named in

honour of the surreal Monty Python show. Music and fun

were on offer at PyConUK, alongside some serious hacking,

very cool projects and some productive coding in worthy

causes. Lets start with the cool tech.

Last years PyConUK Blitz themereappeared as the PyCon poster

Get on board with PythonFeature

From medieval Coventry, via theclassroom, to Africa, and even

operetta and the high seas,PyConUK represents the best of

the Python community

Get on board

with Python




17/100

The PyConUK 2012 conferenceGet on board with Python


FEATURE

Slice of PiPython is the official programming language of the Raspberry

Pi, and Alex Bradbury the lead Linux software developer at

the Raspberry Pi Foundation gave the story so far, and the

challenges ahead. The Raspberry Pi was created as a low-

cost educational tool, but hackers have taken it to their heart,

even running breweries and data centres with it.

The community has contributed many improvements

to the core stack, such as dynamic overclock, and great

software like the 3D Penguins Puzzle game. Theres

much more to be done and Bradbury was frank about

the limitations of the current software while optimistic

about future developments, the possibilities of more edu-

specific software releases and the potential for the Pi in thedeveloping world.

Shoaib Sufi of the Software Sustainability Institute spoke

of his mission to promote better software engineering and

management for better research outcomes. As software

is everywhere, and all-pervasive in science, Sufi demands

better software [to produce] better research.

Intelligent approachBig A, little i was a well-illustrated talk by

games programmer Tendayi Mawushe, pleadingthe case for more use of AI algorithms by developers.

Software provides a better user experience when programs

display awareness of their context, and with good use of

examples like the familiar farmer/fox/goose/corn puzzle

(represented as states and transitions) and moving blocks

games, Mawushe demonstrated making a program give

answers about its own behaviour by tracing method calls.

Various heuristics were examined, giving attendees ideas of

how to bring some AI goodness to their own code.

Dealing with a more mundane annoyance, Vladimir

Keleshev introduced docopt, to build beautiful command-

line interfaces. Replacing the current opaque systems with

a mere 384 lines of code, docopt works from simple rules

to allow the program to take the POSIX standard of usagepattern and turn it into your UI.

As well as the Python reference implementation,

docopt has been implemented in Ruby, CoffeeScript/

Simply pass usage to docopt in this familiar form, and your command-line UI is built

Stephen Hawkes came up with the Victoriantheme of the publicity which also extended to a

Gilbert & Sullivan song

Coders and teachers learnt from each other in a rewarding education sprintCC: @tdobson

We get to introduce free &open source to a widercommunity of childrenand older peopleAlex Bradbury, Raspberry Pi Foundation

Python is the officialprogramming language

of the Raspberry Pi

Catch upVideos of most of the PyConUK 2012 sessions, with

synchronised slides, are up on the PyConUK website,

thanks to the dedicated filming by Birmingham LUGs

Tim Williams:

http://autoview.autotrain.org/course/view.php?id=15

Get involved with creating resources for the nextgeneration of coders at the Python Edu Google Group:

http://goo.gl/BXBLu




18/100


Get on board with PythonFeature

Teaching the teachersBringing the education community to the Python community

nFarmer, grain, goose, fox the AI way represented as states and transitions

Making strenuous efforts to reach the teachingcommunity, the PyCon organisers invited severalteachers to attend a special education track at theconference, led by teacher-turned-coder NicholasTollervey. It included introductory Python tuition,and coders sprinkled around the class to helpthe teachers with their questions. Hearing of thelocked-down conditions of schools IT, fixed onstone-age technology like Internet Explorer 6, wasa shocking discovery for many of the programmers.

Groups of programmers worked with teachersin a coding sprint to produce educational materialaround programming tasks including a text-basedgame and a maze solver. The event introduced

teachers to the collaboration, debate, openness,

meritocracy, sharing of resources and learningfrom the examples of others, as Tollervey put it.

Following the sprint, and a lightningtalk by Miss P (Carrie Philbin, a Google-certified teacher), theres now a mailing listfor Pythonistas who want to contribute toresources for teaching: http://t.co/M7ViLkcP.Additionally, theres an education summit atnext Marchs PyCon in California https://us.pycon.org/2013/events/edusummit/ and,according to Philburn, who was a guest atthe weekends Python Software Foundationmeeting: Happily, it looks like an educationportal will become part of the scope for the

redesign of the python.org website.nTeachers and coders found common causein the education sprint

CC:AlanODonoh

oe

JavaScript, PHP and Bash, with ports to Lua and a C

code generator on their way.

With so many competing talks on the three tracks,

were grateful to the PyConUK organisers for making many of

the talks available as online videos (see Catch up, page 17).

Those who could only make the weekend missed some

informative sessions on the opening Friday, including the

TiddlyWeb architecture originally created as an open

source, reference implementation of an HTTP API for server-

side storage of TiddlyWiki tiddlers, the revolutionary one-

page app giving a reusable nonlinear personal web notebook.

Follow the rabbit

Starting with the Alan Perlis quote, The best book aboutprogramming for the layperson is Alice in Wonderland. But

thats because the best book about anything for the layperson

is Alice in Wonderland, programmer and philosopher David

Miller entertained while drawing lessons from the book.

nMiss P: bringing Python into the classroom

Sarah Mount gave an eloquent summary of the problems of

parallelism and concurrency in Python, and the case for using

Communicating Sequential Processes (CSP). This is an area

of many competing philosophies, and it was good to hear a

knowledgeable opinion put so clearly.

Plenty of space was given for lightning talks over the

two main days, with Lightning Talk Man Harald Massas

Gesamtkunstwerk of anecdotes to fill each gap as speakers

changed laptops and PowerBook VGA dongles. In these five-

minute sessions, delegates learned about mixing dynamic

and static typing; errors and complexity in finding musical

temperaments; prescons, an effective presentation console

for Python demonstrations; using Python for digital forensics;

and easy roll-outs of your own cloud.

Ask the duckFurther highlights included typing to yourself an IRC for

one to log your thoughts with timestamps, and even put

them into version control in a talk that introduced rubber

duck debugging (if you can explain the problem to a rubber

duck, then youre on the path to understanding: try it!);




19/100


The PyConUK 2012 conferenceGet on board with Python

FEATURE

Evidence for DevelopmentUsing Python to deliver effective, evidence-based overseas aid

Much overseas aid is spent inappropriately

at best wasteful, at worst undermining

local markets and farmers self-sufficiency.

Evidence for Development aims to see

that aid gets to where its really needed, by

backing evidence-based decisions with an

understanding of local economics to build

capacity in organisations and institutions

in Africa, Celia Petty, the project founder,

told Linux User & Developer. The World

Bank data is problematic, so the PyConUK

Evidence for Development sprint aimed to

extract something meaningful from it.

Were using the technology to apply

household economy methodology, Petty told

us. This takes a sophisticated view of how

people can meet their food energy needs,

rather than measuring money income alone.

School attendance, lack of access to start-up

capital and many other factors are measured

to see what help people need to achieving

their own economic self-sufficiency.

nDoctor KorovicsFlying Atomic Squid

Daniel Popes Pygame

programming demo

along with a Django-based P2P food market from TransitionCambridge, SustainableSouk.com, which encourages good-

quality local food by allowing anyone to sell or swap what

they produce.

Writing Code for Fun and Profit presented the joys of the side

project, in this case luzme.comwhich offers price comparisons

for eBooks. In further pursuit of fun, Nicholas Tollervey and

Ben Croston (whose day job is Python-automated brewing!)

performed a tuba duet of the Sousa march well-known as the

theme tune toMonty Pythons Flying Circus.

The link between musicianship and coding is a well-known

one, but the opening Sunday lightning talk of an energetic

hip-hop rap, screened Pythonically, was a real surprise. More

conventional, but no less delightful, was the PyConUK song

to the G&S tune used in Tom Lehrers Elements song, with

words (Python keywords in fact) by Tollervey and Stephen

Hawkes, who came up with the Victorian theme of this years

publicity materials.

Quo vadis?Saturday had ended with the keynote Remaking the PSF: The

next ten years of Python by the Python Software Foundations

Van Lindberg, covering the challenges for the language

community and the role of the PSF. As Python has become the

glue language of the movie-making industry, is replacing Perl in

bio-informatics, is beginning to dominate the financial space,

and is finally supplanting Java in the educational world, does it

really matter that it has lost its cool or underdog edge?

Lindberg praised the uniqueness of the Python community,

combining kindness and professionalism, and outlined where

the community and the PSF could go together, with more

local and regional activity. Theres certainly a lot of UK Python

activity already, with regional groups formed at PyConUK 2007

still going strong,

The conference organisers have gone out of their way to

attract as broad a spectrum of people as possible from IT

teachers who are new to Python (see Teaching the teachers,

page 18) to core developers with 100 early-bird tickets and

a budget hotel price offering astonishing value. Combined

with this were beginner and intermediate tutorial days, and

sprints that welcomed all levels of ability. There was even a

non-Python track, touring around Coventrys heritage, for non-

coding partners and offspring.

Future-facingDespite all this, and despite the speaker list containing some

talented and interesting female programmers, a look around

the venue showed more than 90 per cent of attendees were

male a continuing problem in IT generally, but particularly

in the free software community. PyConUK, ever ambitious,

is addressing this problem at source, with direct outreach to

schools to increase the numbers going into programming, both

generally and to Python.

The teachers who attended were taken through introductory

Python programming, then paired with Python programmers

for a development sprint for educational resources. Other

education sessions included a session on Turtle, the Python

version of Logo, and some surprisingly sophisticated uses

such as Sierpinski triangles and Lissajous figures with

very few lines of code. As well as giving the best introduction

to functions that weve heard We teach the computer a

new word discussion ranged over taking Turtle into the

physical world with Lego Mindstorms, to a planned Arduino/

Raspberry Pi DIY oscilloscope.

John Pinner, Zeth and the rest of the organisational team

were a tireless, friendly and helpful presence throughout the

event. Having organised UK PyCons since 2007, and a past

EuroPython, the organisers are not resting on their laurels

next year an additional event is planned around sprints aboard

a ship from Plymouth to Santander and back. If you

want to get involved with both a great community and

a fantastic language, all we can say is get on board!

PyConUK seems tohave hit the sweet spotbetween technicaltell-how and friendlycommunityTim Golden

CC:@ntoll


http://worldmags.net/http://worldmags.net/http://worldmags.net/http://worldmags.net/


20/100

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22/100


Android ports arenow available for

Raspberry Pi, openingup a whole new world ofpossibilities. Heres how

to get started

Raspberry Pi

on your

AdvisorRob Zwetslootmodels

complex systems andis a web developerproficient in Python,Django and PHP. He

loves to experimentwith computing

AndroidInstall




23/100


While one of the main reasons for the creation of the

Raspberry Pi was to offer a cheap way for people to get

into programming and using Linux, there are plenty of

people who see it being used as a replacement for other

forms of computing tasks. With the Pi being so small, the

concept of using it for purposes where space is a premium

is definitely not too far-fetched. Its form factor, weight and

low power requirements make it ideal for use in a number

of situations; however, the software may not always be

the best for the task. Where Linux may be lacking, though,

Android is there to cover it.

Android ports to Raspberry Pi have been in the works for

a little while now, but theyve only just been made a usable

reality thanks to the recent open-sourcing of the VideoCoreGPU driver code. This allows for full hardware acceleration

of Android, something that was previously having to be done

purely by the CPU.

Android can offer a very different experience and

interface than a standard Linux distribution, without having

to obtain custom distros so its optimised for a particular

use. This means you can experiment with the sort of

applications youd want to use Android for without carrying

around multiple SD cards in lieu of wiping them every time.

Thanks to an ever growing development community,

Google recently announced that there had been 25 billion

Android app downloads by the end of September, five

billion up from the number at the end of July, from its

675,000-strong selection. With this rate of expansion, thereare always a number of apps for pretty much anything youd

want an Android device to do. With access to this range of

possibilities on the Raspberry Pi, you can create a system

that has the advantages of using a mobile, user-friendly

OS, with the price of the Pi. And the addition of more I/O

ports from the Pi can make it fit in better than your standard

Android smartphone.

There are three types of projects were going to cover over

the next few pages: a smart TV, a home automation remote

and an in-car computer. While such distros like XBian and

OpenELEC exist for media centres and home theatre PCs

using the Raspberry Pi, the XBMC apps do not have the

same kind of range as Android. With apps going outside the

concept of plain media watching, and even the inclusion

of Android games, theres a lot more you can do with an

Android-run smart TV.

For home automation, there are very mature X10 and

Z-Wave remote control apps available on Android that are

optimised for the kind of interface youd want to use for a

remote control, unlike the mainly mouse-focused tweaking

tools used on Linux distros. Finally, with in-car computers,the touch-screen optimisations and grid array for apps

allow for easy navigation to music, podcast and other

media apps, as well as plenty of fantastic GPS and satellite

navigation applications native to Android.

All you needis a RaspberryPi set up andready to go!

Projects for smart TV, home automation and an in-car computer

Install Android on your Raspberry Pi

Meet RazdroidThe team makes the first project to

get Android on your Pi

Before the release of the VideoCore

drivers, some community members

decided they wanted to have a go

at porting Android to Raspberry Pi,

creating Razdroid. Based mainly onCyanogenMod, the project got far enough to have a couple

of working ports, only limited by the lack of hardware

acceleration. Since then, the Raspberry Pi Foundation

has created its own ports, and eventually released the

VideoCore driver to make ports of Android and other

software a lot smoother.

FEATURE




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Install Android on your Raspberry PiFeature

You can put Android on your Raspberry Pi

right now by visiting the Razdroid site at

www.razdroid.net. There are currently a couple

of images, based around both CyanogenMod 7.2

and 9, with different performance capabilities

and app compatibility. The images can be put on

an SD card using the same method as you would

a Linux distro image, and will run from bootwithout any extra setup needed.

If youre feeling a little more adventurous, you

can compile the images from source instead.

Youll be able to make changes, updates and

additions as well, if you want to improve the

build. The steps on this page will guide you

through a basic build of CyanogenMod 7.2,

based on Android 2.3, for the Raspberry Pi, using

the same files as the Razdroid image to getit working.

Using a standard dd operation, you can get your Raspberry Pi running Android

01 Install librariesYoull need to get the necessarylibraries for the build to work:

$ sudo apt-get install git-core

gnupg flex bison gperf build-

essential zip curl libc6-dev

libncurses5-dev:i386 x11proto-core-

dev libx11-dev:i386 libreadline6-

dev:i386 libgl1-mesa-glx:i386

libgl1-mesa-dev g++-multilib mingw32

openjdk-6-jdk tofrodos python-

markdown libxml2-utils xsltproc

zlib1g-dev:i386

$ sudo ln -s /usr/lib/i386-linux-

gnu/mesa/libGL.so.1 /usr/lib/i386-

linux-gnu/libGL.so

CC:JimK

illock

Its easy to install Android

When the Raspberry Pi was first created, there were some

very specific goals in mind for the finished product. Thanks

to the way it met these goals, it has blown up as the darling

of hobbyists and other tech enthusiasts for all manner of

projects. To further understand the relationship between

the original goals and this new concept of putting Android

on the Raspberry Pi, we spoke to the co-creator of the

Raspberry Pi himself, Eben Upton.

Upton told us that there had never really been any plans

originally for Android to be supported by the Raspberry

Pi. However, developments in recent times had changed

the view of the Foundation: A significant minority of our

customers want to see it, so that makes it important to us.

When the Foundation originally announced it was

working on Android compatibility, it already had a working

prototype. This implementation uses a different kernel

and VideoCore binary image from the one available on

GitHub, explained Upton, which is why weve been

keeping quiet about it so far. This was in late July, and it

took the Foundation a further three months to finally get

the VideoCore drivers open-sourced. Upton told us shortly

before its release why it had been delayed so long: The

issue around releasing the Broadcom Android version is

that wed need a separate microcode image for the GPU,

and we really dont want to fork the community.

Eben Uptonspeaks

Follow our step-by-step guide to get up and running

Without Eben Upton, the Raspberry Pi

would not have been possible. Coming

from a background of computing and

teaching, Upton is currently a technical

director at Broadcom and is responsible

for the overall software and hardware

architecture on the Raspberry Pi.

The co-founder of theRaspberry Pi Foundation




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Projects for smart TV, home automation and an in-car computer

Install Android on your Raspberry Pi

FEATURE

The Play Store willinitially be missingfrom any ports

03Build environmentNow well make a directory for thebuild environment and initialise it for the repo

sync. First:

$ mkdir ~/android_pi

Then move to it and initialise:

$ cd ~/android_pi

$ repo init -u git://github.

com/CyanogenMod/android.git -b

gingerbreadAnd finally sync:

$ repo sync -j16

04 Device treeAfter the sync has finished, create anew directory and download the device tree for

your build:

$ mkdir -p ~/android_pi/device/rpi

$ cd ~/android_pi/device/rpi/

$ git clone https://github.com/

Mathijsz/device_rpi.git

$ mv device_rpi rpi

06 The buildWere now ready to build our Razdroidimage. Make sure to do following to start

the build:

$ source build/envsetup.sh

$ lunch

$ make -j4

Be aware that this may take a while.

02 Working directoryWe need to download the source toa folder that we can make executable. First

create the directory:

$ mkdir ~/bin

Then add it to your path:

$ PATH=~/bin:$PATH

And finally, download and chmod:

$ curl https://dl-ssl.google.com/dl/googlesource/git-repo/repo > ~/bin/

repo

$ chmod a+x ~/bin/repo

05 Initial setupBefore we do the actual build, we needto run a little script to properly prepare the

source code:

$ cd ~/gingerbread_pi/device/rpi/rpi

$ ./initial_setup.sh

$ cd ~/gingerbread_pi

This will automatically make the changes.

Now the source code has been released, via the ARM

Userland on GitHub, and marks the first time a full ARM-

based, multimedia SoC has received vendor-provided open-

sourced drivers, and Broadcom is the first company to open

up its mobile GPU drivers in this way. With it, people can get

down to finishing Android ports and starting new ones.

Android is well known as being used on touch-screen

interfaces, but earlier devices included keyboards

and trackballs. While this has gone out of vogue for

smartphones and other handheld devices, for testing out

your Android-powered Pi it would be useful to have this

option. Is it available now, though?

Im not aware of any significant challenges in this area.

Upton told us when we asked about traditional inputs. We

expect most people would use Android with a mouse and

keyboard, and this seems to be a well-supported option

from ICS (Android 4.0) onward.

So with this native mouse and keyboard support,

youre going to be able to find a lot more applications for a

Raspberry Pi running Android than you could do with even

an Android smartphone. On top of that, you will likely get

the same kind of performance as a Linux distro according

to Upton: I would expect them to be very close in terms

of performance. There may be more UI acceleration in

Android, though, which we hope to bring into Linux.

Finally, one of the main reasons to use Android would be

to access the huge array of apps. We asked Upton about the

issue with Google Play those into the Android scene

might know that CyanogenMod had to remove this

from the standard build for legal reasons. Upton

told us there were currently no plans to obtain

a licence for the store; however, Android

allows you install the APK files

without the store, and these are

usually very easy to obtain.

The conceptof the Raspberry

Pi is a spiritualsuccessor to the

BBC Micro




26/100


Smart TV

Install Android on your Raspberry PiFeature

Use your Raspberry Pi tomake any TV smart

The RaspberrySAFE VESA

Mount add-onattaches the

Pi to mostflat-screen TVs

Game on!Why not turn your smart TV into agames console?

The MOGAcan also

cradle Androidphones, hence

the square

shape

If the buzz around the Ouya is anything to go by, a lot of

people are interested in how to turn Android into a games

console. With a Raspberry Pi running Android, youre

already part way there. While you could use a mouse and

keyboard for some games, others will probably work better

with a joypad, and this is where the MOGA controller comes

in. It connects via Bluetooth to Android and is able to

control a number of Android games.

Get OnLiveIf Android games dont really do it for you, how about full-

blown PC games? The OnLive streaming service allows you

Smart TV is a very recent and popular buzzword

for a more advanced media PC running inside

your TV, which add a whole host of different apps

as well as being able to stream your content

from around a network. Android itself does not

need any specific apps or skinning to turn it into

a functional smart TV the display is already

configured for easy access to all the installed

software, and using home replacement apps

such as Launcher Pro will allow you to increase

the number of on-screen apps if the stock

launcher displays too few for you.

This usage for Android has not gone

unnoticed by other people, with a few

companies already on board. Recently, a high-

profile Kickstarter project was successfully

funded, called Pocket TV by Infinitec, which

while definitely not the first Android-powered

smart TV device, is notable for running off a USB

stick. Like the Pocket TV, the Raspberry Pi is

capable of running 1080p video without an issue.The benefits of Android even go beyond the TV,

as Ahmad Zahran, founder of Infinitec, explains:

[You] get access to all your information,

games, TV streaming channels, work

documents and your entire digital life. Youll

have all the benefits that you get from carrying

your smartphone but with the ability to display

it on a much bigger screen. Imagine walking

into a meeting and doing a presentation

without a laptop.

As well as having access to simple

information apps such as the Weather and

Stocks, you can also use Android widgets to

add a news feed or social network streams, andyou can even connect to streaming websites

like Netflix or the BBC iPlayer, as well as

browsing the web.

Once youve got your Raspberry Pi set up as an

Android smart TV, you may be wondering where

to put it. Well luckily, there are a few cases out

there that support VESA mounts, the standard

used to attach flat-screen TVs to brackets and

walls. The Raspberry SAFE case by Solarbotics

is just the tool to tuck it out the way.

to buy and rent games and play them anywhere, thanks to

all the legwork being done in the cloud. Using the OnLive

Android app, you can access these games from your

Android-powered Raspberry Pi and play them directly

on your television without the need for a bulky PC in your

living room. And it also works out much cheaper than the

official OnLive console.

W o r l d M a

Documents

Raspberry Pi Android InstallationLinux User & Developer Magazine Issue 1202012