Software development and testing are considered to be two sides of the same coin. It is not surprising to see that a lot of focus is given to the testing phase and this only ensures better quality, thereby enhancing the customer satisfaction. Software testing plays a significant role in the success of any project. In simple words, software testing can be defined as a process of verifying and validating that a software application or program meets the business and technical requirements that guided its design and development, and works as expected. It is this testing phase that identifies defects, flaws or errors that need to be fixed.

Software testing has three main purposes:

1. Verification
2. Validation
3. Defect finding

The verification process confirms that the software meets its technical specifications. A specification is a description of a function in terms of a measurable output value given a specific input value under
specific preconditions.

The validation process confirms that the software meets the business requirements.  A defect is a variance between the expected and actual result. The defect’s ultimate source may be traced to a fault introduced in the specification, design, or development (coding) phases.

Software testing answers questions that development testing and code reviews can’t. Some of the questions answered by software testing are:

1. Does it meet the users’ requirements?
2. Does it really work as expected?
3. How does it scale when more users are added?
4. What about its performance?
5. How does it work when more users are added?
6. Is it ready for release?

When we are able to find answers to the above questions, it saves time and money by identifying defects early. It also reduces development downtime. We will be able to provide better customer service by delivering a better application. And the important thing is that it will help us to identify the areas where our programmers need trainings.

The value of software testing is that it goes far beyond testing the underlying code. It also examines the functional behaviour of the application. Behaviour is a function of the code, but it doesn’t always follow that if the behaviour is bad then the code is bad. It’s entirely possible that the code is solid, but the requirements were inaccurately or incompletely collected and communicated. It’s entirely possible that the application can be doing exactly what we’re telling it to do, but we’re not telling it to do the right thing. It is important to understand that the testing provides an opportunity to validate and verify things like the assumptions that went into the requirements, the appropriateness of the systems that the application is to run on etc.

The V-model has gained acceptance because of its simplicity and straightforwardness. If you look at the pictorial representation of V-model, the first test level is unit testing. It is also known as component testing. Unit testing can be considered as a method by which individual units are tested to see whether they are functioning as expected. Unit testing is typically done by software developers, as they are the only ones who understand how a specific unit or module works.

The problem with testing a unit is that it performs only a small part of the functionality of a system, and it relies on co-operating with other parts of the system which may not have been built yet. To overcome this, the developer either builds or uses special software to trick the component into believing it is working in a fully functional system.

The goal of unit testing is to isolate each part of the program and show that the individual parts are correct. Unit testing allows the programmer to refactor code at a later date. This will help in making sure the module still works correctly. It also simplifies integration testing – unit testing helps to eliminate uncertainty in the units themselves. By testing the parts of a program first and then testing the sum of its parts, integration testing becomes much easier.

In unit testing, a series of standalone tests are conducted. Each test examines an individual module that is new or has been modified. Each test validates a single module that, based on the technical design documents, was built to perform a certain task with the expectation that it will behave in a specific way or produce specific results.

Generally, unit tests focus on functionality and reliability, and the entry and exit criteria can be the same for each module or specific to a particular module. Unit testing is done in a test environment prior to system integration. If a defect is discovered during a unit test, the severity of the defect will determine whether or not it will be fixed before the module is approved. In summary, unit tests help developers to reduce the number of bugs, hours spent on debugging, and thereby contributing to more stable software.

Continue to the next page

Follow @LinuxUserMag

So how does a man with such a seemingly high-flying executive background become drawn to work in the world of free and open source software?

Finette came to Mozilla through his wife, Jane, who was running Mozilla’s European marketing. Through her, Finette met with Brendan Eich, Mozilla’s CTO, and Chris Beard, who was working at the time as the foundation’s chief innovation officer and heading up Mozilla Labs. Over dinner in a London restaurant, the three men got into conversation about what an incubator programme for Mozilla could look like.

The conversation continued via email until Chris Beard eventually asked Finette if he would help Mozilla to think the incubator plans through in a more structured way than a dinner conversation.

“From that, I started working for them, literally on the weekends. Because, well, I had a day job, I did run a venture capital firm.
“But the half a day a week turned into a day, then into two days, then three. I got so sucked into the Mozilla fold, and so fascinated by the Mozilla mission, open source, the people and the wider community. We came to this point where I sat down with Chris Beard and he basically said, ‘I really like what you are doing, why don’t you come and join us?’ ”

After a conversation with his partners at the venture fund, they all agreed that Finette should follow his new-found passion for Mozilla. So around three years ago, he started out in a new role heading up Mozilla Labs and working on projects such as Sync/Weave and Personas.

“Then around six months ago I picked up this topic which was in my head and in my heart all this time, which was: how can we help external projects?” explains Finette.
“I had long conversations with Mitchell Baker, our chairwoman, and Gary Kovacs, our new CEO, and a bunch of other people inside Mozilla and they basically all said ‘This is great! We should do this.’ And so, I did.”

So what is WebFWD?
WebFWD is a new unit within Mozilla, whose sole focus is to work with external projects and to help them in the form of an accelerator programme. It is part of a desire I tried to express when I was in Mozilla Labs, which is to work with external projects in a much more structured way than we have done before.

What kind of companies and projects are you looking for? Are there selection criteria?
We do have a theme, but this is malleable and it can and will evolve over time. Very broadly speaking, we look for projects which fit, as a prerequisite, into the Mozilla framework. This is defined by our mission, which is ‘Promote choice and innovation on the internet’, so we are definitely looking for projects which do something on the internet. If you do something really interesting with an Arduino chip, it’s probably not the right project for us. At least not at this point in time.

Secondly, there are a few requirements that we have. We obviously believe that open source is the right model for you to develop and deploy your software. And then we are broadly looking at two areas, the first being deep technology which pushes the web platform itself forward. This could be video in the browser or voice over IP in the browser, this is one of the interesting topics we are currently looking at. In these cases, these kind of projects very often do not have a business model, so I think this is one case where we as Mozilla can be very helpful.

Thirdly, I am also very interested in innovation on the user value side. Currently the two projects we have within WebFWD fall into this category. This is innovating, keeping the users’ interests deep at heart and building solutions for these users.

Which projects is WebFWD currently helping and what are the plans?

One of the companies we are currently working with is called OpenPhoto. And what they do is that they solve this problem: today you have your pictures which are often very close and dear to you; imagine the pictures of your kid growing up, you want to have those pictures around in 20 years time. You have this issue that you have these pictures on a multitude of online services today, so you have got them on Flickr, on Facebook, on Instagram, whatever.

What they do is that they wrote a piece of software that allows you to plug all of these service together, list the pictures and all the metadata: so all the comments and all the tags, and then put them into a storage bucket of your choosing. This could be Dropbox, your own website, Amazon S3, whatever. They make it easy for you to move them around, so that you become master of your own data.

You don’t need to rely on Instagram being around in 20 years time if you want to show your kid this is what you looked like when you were half-a-year old and you had your first spinach. For us this is a really interesting piece of technology, because it clearly solves a user need, in a specific niche where we believe the market has not yet produced the best response.

This is certainly a worthy cause. But if we look at things such as Google’s Data Liberation Front project or Facebook Friend Exporter, Facebook seems quite keen not to let you get to your data: certainly the metadata stemming from interactions on the site. Every time someone opens up a new method of doing this, Facebook seems to shut it down and it becomes a sort of arms race.

Yes this is surely a part of the challenge. But I think this shows you, even more, how much of a need there is for someone standing up and saying I will write a piece of software that allows you to do that. You don’t want to be at the whim of any entity when it comes to something as dear to you as your photos.

Continue to page 2

Follow @LinuxUserMag

Gerry Carr is a busy man. As director of communications at Canonical, it’s his job to make sure that everyone knows what to expect from the launch of Ubuntu 11.10 – also known, in classic Ubuntu fashion, by its animal codename Oneiric Ocelot.

“We’re describing it as an iteration rather than a revolution,” Carr explains of the release his company has spent the last six months shepherding towards release. “Really, it’s the first step towards this drive that we have to break down the separation between the operating system and the applications – the legacy of where Ubuntu’s come from – and the cloud, and the Internet, so basically where people get content and applications from outside of their local PCs.”

Carr, previously Canonical’s marketing manager, is used to having to sell Ubuntu releases to the Linux-using public. When he took responsibility for the Ubuntu.com site back in 2008, he spoke publicly of his desire to demonstrate what could be achieved with truly open tools – something which won him a great deal of respect in the community, even if he admitted to cheating occasionally with a copy of Adobe Photoshop.

Now, as communications director, Carr has the responsibility of keeping the community – and our readership – informed as to the goings-on at Canonical.

Talk us through the major new features of Ubuntu 11.10 ‘Oneiric Ocelot,’ compared to the previous release.

“One of the most significant steps forward is the work we’ve done on this release to the Ubuntu Software Centre. That changed in this release in three ways. First of all, on a basic level, just in the variety and range and the number of applications that we’re making available through the Ubuntu Software Centre now, which will only ramp up significantly across the lifetime of Ubuntu 11.10.

“The other significant step forward, which is a very recent one but we’re already starting to see the benefits from, is the release of developer.ubuntu.com. Basically, what developer.ubuntu.com does is make it much more transparent about how to make an application available on Ubuntu, and at the same time how to develop an application natively for the platform.

“Finally, we’ve done a fair amount of work to make it much more integrated into the Ubuntu experience itself, so for instance if I got to Dash and search for applications, it’ll prompt me with applications that are locally installed and also with applications that are available via the Ubuntu Software Centre. That’s a big step forward we’ve made for Ubuntu 11.10, and I think it will become a more popular yet less visible part of what we’re making available ongoing.”

When Ubuntu 11.04 launched with Unity, there was feeling in the community that it wasn’t quite ready for release. Is that something that’s been addressed in this latest release?

“You learn far more by releasing a product than you do by developing it under wraps. I mean, obviously, we believe that the product is and was ready for prime-time, if you like, for a vast majority of use cases and a vast majority of users. We knew we were running pretty tight towards the release date of that product, and we had stopgaps in place if we felt it wasn’t ready but we didn’t have to use them.

“It was ready, but there will be some faults. We knew we wanted to get it out at least a year before the LTS releases, to give it that time to iron out the edges. 11.10 has six months additional development in terms of making it smoother and faster and better than Ubuntu 11.04.

“The Dash has become much more mature in this release. It was its first release with Ubuntu 11.04, and I think with 11.10 users will start to realise the centrality of its place in how to navigate their way around this operating system. The Launcher, we’ve done a lot of work – and learnt a lot about this – with improving the algorithms for search.

“We’ve broken down more the difference of whether I’m searching for applications or whether I’m searching for files, that’s much more of a distinctive location for either. We’ve also, with this release, made clearer what the Lens concept is: you can consider it a subset of Dash, which allows us to focus on a single type of content.

“We released 11.04 because we thought it was ready then. We knew that there would be some faults, but we’ve had six months to iron out those faults and I think 11.10 is better, and 12.04 will be better again – but that’s the inevitability of development cycles in software.”

You mention making the concept of Lenses clearer – what are the best examples of real-world uses of Lenses in Ubuntu?

“For a few months now there’s been a Help Lens, which is a Lens that accesses Ask Ubuntu – an external site with lots of help and support queries and answers for Ubuntu. So, a Lens uses the same interface, more or less, as the Dash, so users don’t have to learn a new interface in order to access different types of content.

“With this release, we’re bringing out the Music Lens, which offers a Dash-like experience and allows you to use the search bar to search for, let’s say, Abba – it’ll display all the Abba that you have locally on your machine, and it’ll also display any Abba available in the Ubuntu One cloud, and then also it will – and I’m not quite sure if this is going to land at release, or just after – but basically it’ll also allow you to access all the Abba that’s available on the Amazon Music Store or on the Ubuntu One Music Store, so I can purchase that directly within the same Lens.

“Once purchased that music will be made available through to Ubuntu One Cloud so I can stream that music to my local Banshee player on Ubuntu or I can play it on my iPhone or on my Android device, or however I choose to listen to my music. So, that represents a breakdown of where my music is available, how I access this music – so basically we’re sort of elevating the content away from the operating system. We’re starting to see that in various real ways that we hope people will find convenient and useful.”

We couldn’t help but notice that the traditional Ubuntu mail client, Evolution, has been swapped out in favour of Mozilla’s Thunderbird. What prompted the change?

“The short answer: user preference. Basically, at each UDS – which is the developer summit we hold every six months – we run through a check of the default applications, and ask whether they’re the right default applications ongoing. We were aware that lots and lots of users were using Thunderbird as opposed to Evolution as their preferred email client, but that had certain inconveniences: for instance, if I click on an email address that’s in a document it’ll automatically start up Evolution, but most of our users seemed to be using Thunderbird.

“So, now, if I do the same thing it’ll start up Thunderbird, which is the email client I prefer. So, really, it wasn’t a case of fault with Evolution, it was really a case of preference for Thunderbird and the fact that reality seemed to be that most of our users were using Thunderbird over Evolution, so it seemed a natural switch. We’ll still make Evolution available through the Ubuntu Software Centre – I’m 90 per cent, 95 per cent sure of that – so it’s still a simple install for users who want to use it, but it’s not the default email client from 11.10 on.”

Are you concerned that the decision to remove Ubuntu Classic – which allowed Ubuntu 11.04 users to drop to a classic GNOME interface – in this release will get a negative reaction from the community?

“We’re concerned in a sense that we never want to do anything to deliberately lose users, and we’re obviously concerned about anything that people would have a negative reaction to – but we’ve been pretty open and consistent around the fact that we think that the new user interface for Ubuntu is the direction in which we’re moving. We know that that’s caused problems, let’s put it that way, for certain sections of users around Ubuntu.

“We brought out the two experiences – the default 3D experience, and then the GNOME experience – because we needed to give people the option. We’re more confident now that we don’t need to have that second option – the Unity 2D option is ready.

“What we said then, we continue to say: we are committed to Unity, we see Unity as – for a variety of reasons, and across a variety of form-factors – as the principle driving force for where Ubuntu is going, so it makes consistent sense for us, at least, to make Unity 2D the default secondary experience for users with graphic-restricted PCs.

“So, are we concerned? Yes. Do we hope that people will come with us? Yes. Are we going to change our minds on that? No. We know it’s an argument that we have to win, we know it’s an argument we have to win over time, we know it’s an argument we’re not going to win with absolutely everybody, but we think it’s the right thing to do and this is consistent with that decision.”

Canonical has been very vocal about its support for the ARM architecture in the past – how is that project progressing?

“With this release, we’re releasing a tech preview of Ubuntu Server for ARM as well – Ubuntu Server 11.10 will be available on the ARM architecture for the first time, I think, any general-purpose software system has been available as a server technology, so that’s a very significant feature.

“We’ve done a lot of work to make the LAMP stack available on the ARM server product, so there are real applications for people to run and test out the applicability of ARM for data-centre use. We’ve done work to make virtualisation container technology available on ARM, which allows us to make OpenStack or Ubuntu Cloud available on ARM for the first time.

“There’s a lot of firsts in there on the server side. It is a tech preview, there’s a limited range of architectures available out there – so it’s not for everyone, put it that way. We’re not expecting production on these devices for some time, but ourselves and ARM are extremely excited that we’re starting to see real movement over there.

“On the client side, we going to start seeing ARM devices appear like netbooks – we’ll start seeing those running Ubuntu pretty soon. There isn’t a legacy of applications out there that have been in the market for as long as an x86 PC-type experience, but that work is ongoing. There are, obviously, areas where it makes sense to port applications across to ARM, and it’s a case of the industry deciding which ones make the most sense to focus on.”

Ubuntu has long been made available as alpha and beta versions for community testing before each version gets an official release. How important is the community feedback in the development of the distribution?

“Well, it’s hugely important – that’s why we do it. I can’t characterise how important it is, but as you know we have an alpha programme which is out very soon after the release of the previous product, we have an extended beta programme, we have many, many, many thousands of participants in that – the bug reports are probably the most essential part of making sure that our stability is right, and the features are working.

“It’s certainly something that our development teams pay huge attention to, the entire community pays huge attention to. It’ll become even more important with the next release, which is the 12.04 release, which is all about stability and precision as Mark [Shuttleworth] announced. So, the beta programme, the extended beta programme, the entire development process which you could call a beta programme – it’s what Ubuntu is about, it’s how we crowdsource and how we make sure that the product is quality is by getting feedback around where we’ve fallen down and to try and fix it.”

Thanking Carr for his time, we ask him if he has a message he’d like to pass on to our readership. “It’s not for me to lecture people about how they should or shouldn’t react to releases,” he explains, “but I think that they should understand that what we’re trying to do.

“The best of our efforts, and what we talk about all the time, is basically ‘how do we get free software into the hands of more people?’ We take decisions around interface design, product design and application integration, but they’re all designed for a single purpose: to put more free software into the hands of more people.”

It’s clear from his words that it’s a topic Carr feels passionate about, and one he believes is fully supported by his employer. “While we may disagree in terms of tactics,” he admits wryly, “the strategy is shared between us and the broader community in open source and elsewhere.”

Ubuntu 11.10 ‘Oneiric Ocelot’ is a launch which Carr and his colleagues is hoping will win back support lost during the transition to Unity with 11.04, and will be followed in April next year with the company’s latest Long Term Support – LTS – release, Ubuntu 12.04 ‘Precise Pangolin.’

Read out our review of Ubuntu 11.10

Follow @LinuxUserMag

It’s time to set the record straight, and we here at Linux User think the best way of doing that is with a good old-fashioned head-to-head challenge. We’ve taken the reference implementations of both GNOME 3 and Unity – the official Live CD and Ubuntu 11.04 respectively – and given them a good going over, ranking them on familiarity for existing GNOME users, performance, compatibility, features, and extensibility.

We’ve also spoken to those in the know to get the insider view on matters. For GNOME there’s Federico Mena, co-founder of the project and GNOME 3 developer. Fighting for Unity we have Neil Patel, Canonical’s technical lead for desktop experience. Both will be offering their own insights and opinions to help settle the matter once and for all…

We’ve broken down the feature into the key areas of usability GNOME 3 and Unity move away from the GNOME 2.x (not to mention KDE) ‘norms’. You can use the links below to jump through sections…

Familiarity - Both GNOME 3 and Unity are very different beasts to GNOME 2, but which takes the most learning?
Performance and Compatibility - Having a whizz-bang user interface is great, but not if it comes at the cost of performance…
Features – With the problems out of the way, which of the two offers the most feature-rich user experience?
Extensibility – Devs and advanced users will be pleased to hear that both offer possibilities for customisation – but which wins out?
And the winner is… – we’ll round-up the pros and cons of each, but there’s got to be a winner. This is it…

Continue to Page 2: GNOME 3 vs Unity – Familiarity

The terminal emulator grew beyond its original purpose and by August 1991 Torvalds was able to announce to the comp.os.minix newsgroup on Usenet that he was “doing a (free) operating system (just a hobby, won’t be big and professional like GNU) for 386(486) AT clones.” The first iteration of the Linux kernel was written explicitly to explore the workings of the 80386 chip on Torvalds’s computer using GCC, the GNU C Compiler, and would “probably never support anything other than AT-hard disks, as that’s all I have.”

The kernel was machine-specific and monolithic, and quickly attracted followers and critics. GNU and Linux fulfilled a need among a growing band of enthusiasts and hobbyists, academics and coders, who had grown up in the age of the Sinclair QL and BBC Microcomputer and saw a computer as something you could open up and play with, break down and program – and, when push comes to shove, improve.

Others saw it differently. As early as January 1992 Tanenbaum declared Linux to be ‘obsolete’ on the grounds that Linux was tied to the quirks of the Intel chip and represented “a giant step back into the 1970s” – monolithic kernels were a thing of the past and would be replaced by microkernels, such as the GNU Hurd, which would give much greater performance, security, freedom and flexibility.

As events were to prove, the microkernel imposed problems on the Hurd developers that were hard to surmount, and a monolithic kernel made it easier to fulfil the first imperative of all free software developers, which was a working free operating system.

The Hurd slipped by the wayside, and in a few short years Linux, the kernel that wasn’t portable, was available on more devices across a wider range of hardware than any other operating system that has ever existed.

What might have been
However, all this might never have happened if the Hurd, or a version of BSD for Intel chips, had been in place by the middle of 1991. Work on the GNU operating system – “a complete UNIX-compatible software system called GNU (for ‘GNU’s Not UNIX’)” – had been started back in the early Eighties, and it had been seven or eight years in the making by the time that Linux came along.

“If the GNU kernel had been ready last spring,” Linus Torvalds wrote in January 1992, “I’d not have bothered to even start my project: the fact is that it wasn’t and still isn’t.”

Richard Stallman had founded the GNU project in September 1983, but before a kernel could come into being, the bits and pieces that made the kernel possible had to be written – the editors and compilers, Bash, Make, Autoconf, Emacs, GCC and all the others. The story of their evolution, and Stallman’s experience of the obstacles he encountered, especially during the development of GNU Emacs, led to a hardening of the philosophical concepts behind free software and their encapsulation in the GPL, which didn’t come into being until 1989. By then the tools were falling into place. The kernel was to be the last part of the jigsaw.

Continue to page 2

em>This article originally appeared in issue 98 of Linux User & Developer magazine. Subscribe and save more than 30% and receive our exclusive money back guarantee – click here to find out more.

These days, many consumer electronics devices run some form of embedded Linux-based environment. There are popular home Wi‑Fi routers from companies like Linksys, Android phones from Google, and TV set-top boxes galore. These devices tend to have two things in common: they run an embedded form of Linux intended for more resource-constrained hardware (less RAM etc), and they often use ARM-based system-on-chip (SoC) processors – combining a CPU with various peripheral devices on a single chip – in place of the Intel x86-based processors found in most consumer PCs.

While popular, many enthusiasts find these devices inaccessible from a development viewpoint, being content to try some well-tested ‘alternative’ firmware in their home router (such as DD-WRT or OpenWRT) but not really feeling empowered to build their own embedded Linux devices or get involved with embedded kernel development. After all, building such a device from scratch is outside of the resources available to or capability of most enthusiasts. Few of us have access to the software and tools required to make complex multi-layered circuit boards, even if we do have the necessary understanding to put it all together. In addition, because consumer electronics hardware is not generally intended to be modified by consumers, many people don’t want to risk ‘bricking’ their expensive gadgets in the process of learning more about how they work, or to enhance their design.

Enter BeagleBoard. This is the brainchild of a small group of volunteers (many of whom are Texas Instruments employees – TI’s chips are used in the design) who were frustrated at the lack of affordable development boards, and with the kinds of concerns faced by those seeking to get involved with embedded development. Their attempt to remove these barriers led to a small, (relatively) low-cost, durable (hard to ‘brick’) ARM-based development platform that couples an open source hardware design that anyone can look at with open source software. The project is supported by a strong community of users and developers who support each other and welcome newcomers. That it also benefits TI to have developers using its parts is obvious, but that in itself isn’t necessary a bad thing as such a project does need some kind of backing.

Physically, the latest ‘xM’ version of the BeagleBoard is an 8.25 x 8.25cm (3.25” x 3.25”) circuit board that includes a powerful 1GHz ARM Cortex-A8 SoC processor, 512MB of DDR RAM, microSD card slot, 4-port USB hub, 100MBit Ethernet, audio input and output, S-video and DVI-D output, and a lot of developer-friendly connections we’ll get on to later in this article. You can pick up a BeagleBoard from a number of suppliers by visiting the project website at beagleboard.org and clicking on the link for a distributor covering your particular world region. The boards retail for around $150 USD, which is a tremendous bargain considering the kinds of application it empowers you to build. These latest-generation ARM Cortex-A8 cores are fundamentally the same design as that used in the Google Nexus S, iPhone (Apple’s A4 processor is effectively a derivative), as well as many other gadgets, and even a new generation of ARM netbooks.

Setting up BeagleBoard
Developing with BeagleBoard, like working with other embedded devices, generally involves the use of two systems: a desktop development system and the board itself. The BeagleBoard is fast by embedded standards. It’ll give your phone a run for its money, but not your fancy desktop or recent laptop.

Therefore, the general established practice for working with embedded Linux devices is to develop and build software on a ‘host’ PC system (on which all of the general tools you are used to having are available) and then copy the results to the BeagleBoard using its network connection, or by removing and directly updating its microSD card. Many developers will use a mixed approach, installing a general-purpose OS onto the BeagleBoard and interfacing with it over the network, running some commands on the device itself, but offloading bigger tasks (like a kernel compile) to a faster desktop development system.

To get going, you will attach the BeagleBoard to a 5V power source. This can be either the 5V connection directly, or the USB OTG mini port from which it can draw enough power just to run the board without external peripherals. In my case, I use an externally powered USB hub and purchased the optional 5V power cable that simply plugs into the external hub for power. You will also need to attach a serial cable to the serial port on the board. This will be used to interact with BeagleBoard on its console, much as you would on a regular desktop not running a graphical environment. Many PCs don’t come with serial ports any more, but an inexpensive USB adaptor can be bought from any PC store. After attaching the serial dongle (which fits directly onto the port on the board without cables), you can configure software such as minicom, screen, or any other terminal emulator that came with your choice of OS on the host system. By default, you will want to use a 115200 baud rate, 8 bits, no parity and one stop bit. The serial device path may vary, but on Linux it will be similar to /dev/ttyUSB0.

BeagleBoard comes with a 4GB microSD card containing validation software that you can use (actually, a release of the Angstrom distribution) and which should boot after you insert the card and power on the board. If you have set things up correctly, you will see a simple banner and be able to type shell commands. There are various alternative images available on the BeagleBoard website, so you can replace the ‘validation’ factory image with a version of Android built for BeagleBoard, or Ubuntu, and so on. I chose to install Debian Squeeze on my BeagleBoard, following instructions on the BeagleBoard wiki and using the updated kernel images available from Robert Nelson to get started. At this point, the latest upstream kernels (from 2.6.38 onwards) support most of the hardware out of the box without requiring patching or modification.

Continue to: Page 2 – Porting the kernel and ARM architecture explained

Click here for your chance to win a 12 month LCN.com Linux VPS Enterprise Package worth £500!

Return to the homepage
See what else features in issue 98

This article originally appeared in issue 94 of Linux User & Developer magazine. Subscribe and save more than 30% and receive our exclusive money back guarantee – click here to find out more.

Distilling down the hundreds of possible virtualisation tips and tricks to a mere 20 is a good trick in itself. Many of these techniques are generic in nature and can apply to any vendor’s virtualization; however, some are specific to VMware. In all cases, the tips and tricks emerged by experience with a variety of virtualization technologies.

Virtualization is about placing workloads into virtual machines, and perhaps the most often asked questions about virtualization have to do with performance of those virtual machines. Therefore, most of the tips given here relate to virtual machine performance enhancement and making the user’s experience richer and less problematic than traditional hardware-based, physical systems.

Other than performance, the remainder of the tips are associated with virtualization best practices for medium to large implementations. Although those with smaller environments will also benefit from these tips, many of the problems they solve arise as virtual machine numbers increase to 50 or more.

Use VMs for disposable systems
VMs are the perfect environment for creating honeypots, for malware test systems and for exploring the effects of virus payloads. VMs created from templates (see Keep Host Systems Patched) and then isolated for such systems are an excellent way to explore dangers on production systems without exposing the latter to the threat. Disable network interfaces when dealing with viruses or malware so that the threats remain on the VM and don’t affect other systems, virtual or physical. When using Windows VMs for this purpose, turn off System Restore so that any files altered or destroyed during testing won’t be kept when the system is powered on again.

Use VM templates
Virtual machine templates allow the virtualisation administrator to deploy new virtual machines quickly and consistently with a standard operating system image. Templates are converted VMs that include patches, updates and guest additions and are ready for deployment. A template is equivalent to a ‘gold’ image, from which most or all of your production, development and test systems are created. A template can be converted to a virtual machine to receive new patches and then converted back to a template.

Building VM hosts
Virtual host hardware must consist of multi-processor, 64-bit CPUs; adequate RAM for several VMs; ample disk space that allows for growth; and Gigabit network interfaces. Multiple network interfaces are needed to handle VM traffic and to provide an isolated backup interface. Most server-grade hardware meets these requirements. If older equipment is used for this purpose, verify that the systems meet the minimum requirements of 64‑bit, multi-processor and RAM that can expand above 8GB. 8GB is considered a bare minimum for a virtual host system.

Thick provisioning for virtual disks
When provisioning a new virtual machine (VM) or creating a new disk for a VM, use thick provisioning when performance is important or when disk contents change often. Thick provisioning refers to the static allocation of disk space to a virtual disk. So if you create a 30GB virtual disk, it consumes exactly 30GB of storage from your storage pool. The alternative to thick provisioning is thin provisioning, or dynamically expanding disks. When created, a thin-provisioned disk consumes a minimal amount of space and expands as required by data. The disk will grow to its predetermined size on demand. Thin provisioning saves disk space, but performance is the trade-off. The rule is that if your virtual disk needs optimal performance or will have data regularly written to it, opt for thick provisioning.

Separate disk image locations for heavy workloads
VMs experiencing performance problems should have their disk images separated to different storage locations. For example, a database system with problems that uses one virtual disk for the operating system, a second one for data storage and a third for logs has its disks on the same LUN. Move the OS virtual disk to a different LUN and move the logs virtual disk to a LUN that doesn’t contain either the OS or the data for that VM. Performance will increase for the VM, potentially mitigating the associated complaints.

Follow physical machine security rules
Virtual machines are no more or less secure than their physical counterparts. With that information in mind, patch, service-pack, update and protect VMs in an equivalent manner to that for physical systems. Anti-virus software, anti-spyware software and firewalls are all still needed in a virtual environment. Remove or disable unused services and only allow secure protocols into and out of systems. Where possible, use the secure version of all services. For example, use SSH, SCP, SFTP and HTTPS instead of the less secure Telnet, RCP, FTP and HTTP.

SAN storage
Large virtualisation implementations couldn’t thrive without SAN storage. SAN, or Storage Area Network, is how contemporary server systems use disk space. Large drive arrays connect to your systems via host bus adapters (HBAs), fibre cables and SAN switches. SAN systems provide fast disk access suitable for databases, logs and other write-intensive applications. SCSI disks are the better performers, with SATA drives running a distant second. Often used simultaneously, but for different needs, SCSI-based SAN and SATA-based SAN is preferred over local disk storage because of the dual-fibre channel setup, the various RAID possibilities and the lack of a single point of failure.

Continue to page 2

Linux User & Developer is the magazine for the GNU Generation
Click here to try 3 issues for £1

Ubuntu 10.10 Netbook Edition

Canonical, the firm behind Ubuntu, has been experimenting with an interface designed specifically for netbooks for some time…

The current release of the netbook-oriented version of Ubuntu is the company’s second major attempt to develop a netbook-friendly graphical layer sitting on top of the Ubuntu base. The latter means that Ubuntu Netbook Remix (UNR) provides all the creature comforts Ubuntu is known for, including a user-friendly installer and excellent hardware support.

Similar to the latest Ubuntu release, UNR 10.10 comes with a redesigned installer that makes the process even more straightforward than before. The wizard asks a few simple questions and zips through the installation in 15-20 minutes. As you’d expect, UNR does a great job at detecting and configuring hardware. On our test machine, pretty much everything worked out of the box, including the wireless interface, the webcam, the Bluetooth module, and the sound and graphics cards. There were a few exceptions, though: neither the microphone nor the function key worked out of the box.

Although supposedly UNR (and the desktop version of Ubuntu for that matter) sports improvements in booting times, you probably won’t notice any difference on a system with a conventional hard disk. However, UNR boots mind-bogglingly fast on netbooks with solid-state drives. On our test system, UNR zoomed through the boot sequence in about 10 seconds.

Of course, UNR’s main attraction is the brand-new Unity interface, designed to make the most of a netbook’s limited screen estate. While the netbook interface in the previous version of UNR took over the entire desktop, Unity represents a more subtle approach. It adds a scrollable vertical task management panel to the left side of the screen which provides quick access to frequently used applications and destinations. In addition to that, the Application icon gives you access to the screen containing big colourful shortcuts to the most essential applications, such as a web browser and Ubuntu Software Center, as well as folders and software sections. Unity also offers a few convenient features that can boost your efficiency. The Search bar, for example, lets you quickly locate the application of the document you need. Start typing the name of the application or file and the system narrows the result in real-time.

While the Unity interface works surprisingly well, it does have a few annoying quirks. The vertical placement of the launcher makes a lot of sense, but it doesn’t seem to be possible to hide it when it’s not in use, so you can’t reclaim this portion of screen for use with other applications. You can remove and add applications to the vertical task management panel, but you can’t add folders. And you can neither add nor remove items from the shortcut screen.

Despite these minor shortcomings, Unity is an impressive feat of software design which, combined with the solid Ubuntu foundation, makes UNR a prime candidate for your netbook.

Scores
Here’s how  Ubuntu 10.10 Netbook edition measures up…

Installation & hardware support: 9/10
UNR’s installer is hands down the most user-friendly installation tool out there

Ease of use: 8/10
The new Unity interface is slick and easy to get to grips with. It does have a couple of shortcomings, though

Cloud & social features: 8/10
Similar to the desktop version of Ubuntu, UNR provides integration with the Ubuntu One service. The Me menu acts as a hub for all your social activities, but the default Gwibber social client is not
the best choice for the netbook

Software: 9/10
A couple of odd choices (Cheese webcam tool but no Skype?). However, they can be easily fixed using the excellent Ubuntu Software Center tool

Overall:
The new Unity interface works surprisingly well, but it does have a few annoying quirks

Page 2 – Jolicloud 1.0

Goup test reviews:
Page 1: Ubuntu 10.10 Netbook Edition
Page 2: Jolicloud 1.0
Page 3: Easy Peasy
Page 4: Kubuntu Plasma Netbook desktop
Page 5: Final verdict

Return to the Linux homepage

This article originally appeared in issue 93 of Linux User & Developer magazine. Subscribe and save more than 30% and receive our exclusive money back guarantee – click here to find out more.

This article is designed to look at a large range of tips and techniques – here’s a breakdown of what this article touches on and where:

Page 2
Running commands from C
Creating and applying patches
Conditional compilation

Page 3
Developing for the Text User Interface
Building multimedia applications

Page 4
Using an embedded SQL database

Page 5
Developing multicore applications
CMaking instead of just Making
Eclipse CDT tips

Page 6
KDevelop 4 Playground plug-ins
Best practices for writing cross platform applications

Deciding your path
There are multiple ways by which you can program in Linux. Linux supports most of the modern types of programming environment available today. Based on your interest and objective, you can choose from the following programming methods…

Shell programming: A shell is the userland portion of Linux which provides the command-line interface for UNIX-like operating systems, including Linux. In addition to providing a command-line interface, shells are also capable of executing scripts called shell scripts. These scripts can be used for a wide variety of tasks, such as system configuration, file manipulation and troubleshooting. Shell scripting supports basic programming constructs such as maths, looping variables etc, but what makes it different from a traditional programming language is its ease of use and availability. Incidentally, shell programming is required for any Linux certification program, or for that matter any UNIX certification program.

Interpreted languages: A significant portion on Linux is made up of interpreted languages such as Perl, Python and Ruby. The same can also be used by you to program Linux. These languages are often dynamic and are less restrictive than the traditional programming languages, while providing the same level of functionality. Hence they became popular in many fields, such as system administration and web programming.

High-level compiled languages: They are the big boss of Linux development environments. More than 95% of the Linux OS and its applications are built using compiled languages. Linux supports most of the compiled languages – including the most popular, C and C++. Use this route if you want to conqueror the Linux development world the good old traditional way.

This article is more inclined towards C/C++ due to the enormous open source adoption.

Finding programming languages supported by GCC
GCC (GNU Compiler Collection) is the mother of all compilers that is also native to the Linux programming environment. As the name suggests, GCC is not just a compiler for a language but rather a compiler collection that supports many programming languages. Depending upon the specific Linux distribution you are using, GCC’s support for languages could vary. To find out which languages are supported, perform the following command:

$ gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion=’Ubuntu 4.4.3-4ubuntu5’ --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared --enable-multiarch --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4 --program-suffix=-4.4 --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-plugin --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i486 --with-tune=generic --enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)

This command gives a bunch of information, including the configure options used when building this compiler. ‘–enable-languages’ indicates the languages supported by this compiler. In this case it is ‘–enable-languages=c,c++,fortran,objc,obj-c++’, so the supported languages are C, C++, FORTAN, Objective-C and Objective-C++.

Coloured GCC output
GCC provides excellent information when your code is not compiling or linking properly. But when you are compiling a large project, GCC’s output may not be very helpful. The colorgcc tool can come very handy in this situation. It is a Perl script to colourise the terminal output of GCC, making it easier for you to locate error messages, syntax errors and linking errors within longer compiler outputs. Search for ‘colorgcc’ in your distribution’s package manager, or you can download it from http://schlueters.de/colorgcc.1.3.2.txt. If you want to use colorgcc for all of your GCC-based projects, you will need to set an alias mapping GCC to colorgcc.

Be alarmed
By default GCC prints a rather restrictive set of warnings and errors that inform you about the potential and fatal issues with your code. To get an even better perspective of the code, you can increase the level of warnings generated by GCC, by using the option ‘-Wall’ .

For example, for the following code :
@code: System.c

//#include <stdio.h>
//#include <stdlib.h>
void main()
{
 printf (“Files in Directory are :\n”);
 system(“ls -l”);
}

when compiled without -Wall option
kunal@ubuntu-vm-kdeo:~/tips$ gcc system.c -o system
system.c: In function ‘main’:
system.c:6: warning: incompatible implicit declaration of built-in function ‘printf’

when compiled with -Wall option
kunal@ubuntu-vm-kdeo:~/tips$ gcc -Wall system.c -o system
system.c:4: warning: return type of ‘main’ is not ‘int’
system.c: In function ‘main’:
system.c:6: warning: implicit declaration of function ‘printf’
system.c:6: warning: incompatible implicit declaration of built-in function ‘printf’
system.c:7: warning: implicit declaration of function ‘system’

Be disciplined
Experienced programmers will tell you that ignoring warnings is a bad practice. One way to get rid of warnings from your code is to pay attention to the warnings and fix the code. But if you get too lazy, this may method may not work for you. Meet the second option… You ask the compiler to treat warnings as errors. Hence, the compiler won’t even compile your program until you make your code warning-free. This compiler forces a discipline of writing warning-free code.
To treat warnings as errors, you can use the GCC option ‘-Werror’.

Example:

kunal@ubuntu-vm-kdeo:~/tips$ gcc -Wall -Werror system.c -o system
cc1: warnings being treated as errors
system.c:4: error: return type of ‘main’ is not ‘int’
system.c: In function ‘main’:
system.c:6: error: implicit declaration of function ‘printf’
system.c:6: error: incompatible implicit declaration of built-in function ‘printf’
system.c:7: error: implicit declaration of function ‘system’

This article originally appeared in issue 93 of Linux User & Developer magazine. Subscribe and save more than 30% and receive our exclusive money back guarantee – click here to find out more.

While most folks have forgotten about the company’s origin in AOL’s Netscape acquisition, and perhaps even the name of the non-profit itself, everyone knows Firefox. And Linux users, in particular, depend on this non-profit’s products just as much as they rely on any other piece of open source software.

Firefox 4 has been in development now for almost three years. The folks at Mozilla have had some clear goals for version 4: faster JavaScript performance, easier AJAX debugging and full HTML 5 support. The official ship date, however, is still ‘when it’s done’.

But Firefox 4 is not the only browser on the block any more. The days of Mozilla fighting the good fight alone against the Borg-ish Microsoft are gone. Google’s Chrome and Apple’s Safari have utilised WebKit to become compelling and nimble browsers in their own right. Microsoft’s Internet Explorer 9 is touted as a standards-compliant liberator of the ‘Beautiful Web’. And upstart browser Opera has succeeded in drawing away some of the most vitriolic of browser lovers, the same people who used to make web videos asking strangers on the street why they used Firefox.

Indeed, the days when the giant orange lizard stood shoulder to shoulder with Tux and the BSD devil seem to be gone. Mozilla is still a great company with plenty of interesting projects, like Thunderbird, Sunbird and Bugzilla. But Firefox is no longer the only standards-compliant choice for the open web.

Mike Shaver, vice president of engineering at Mozilla, said he is actually impressed by much of the work being done in the other browsers. He joked that he was formerly most proud of the Internet Explorer 7 release, because it showed that Microsoft was playing catch-up after the abysmal IE6 release. But today, he’s unable to take simple potshots at the competition, because the competition has finally come around to the power of standards.

Page 2 – Standards issues

You might also like:
Firefox 4 beta review by Joe Brockmeier
Linux User homepage

This article originally appeared in issue 92 of Linux User & Developer magazine. Subscribe and save more than 30% and receive our exclusive money back guarantee – click here to find out more.

Not since Moses came down from Mount Sinai has there been such excitement about a tablet. Launched in April, the Apple iPad was an overnight sensation. Anyone would think that it was the first tablet device ever made, but in fact they have been around for ages. Not that most people were aware of them. The first commercially available tablet, the GRiDPad (based on MS-DOS) appeared back in 1989. Other devices followed and by the early 2000s the tablet was being touted as the ‘next big thing’. It didn’t happen then, possibly because the technology of the time wasn’t up to creating the sort of user-friendly internet media tablets envisioned. And so the tablet market continued to be a niche one: before the launch of the iPad, it accounted for a mere one per cent of the personal computer market.

The iPad launch changed all that. All that frenzied media coverage has finally made consumers aware of the tablet form factor. Surveys by Forrester Research showed that by June, 95 per cent of consumers were aware of the iPad. They might not have known they needed, or wanted, a tablet before, but plenty have been buying them.

With over 3.5 million iPads sold to date – Apple CEO Steve Jobs boasting “we’ve sold one every three seconds since we launched it” – and ABI Research forecasting a total of 11 million media tablet shipments in 2010, it’s no wonder that most OEMs (original equipment manufacturers) want a slice of the action. Some may also be fearful of the iPad’s effect on their own netbook sales: a report from DisplaySearch noted, “In the second half of the year, as additional slates are launched, the clamshell-style mini-note PC [netbook] could continue to lose share.”

So it is that most major OEMs – and lots of lesser-known enterprises worldwide – are working on their own tablet devices, mainly based on the Android platform. Barely a week goes by without another one being announced or rumoured, and major OEMs such as Samsung, Toshiba, Archos and ViewSonic used the recent IFA technology show in Berlin to showcase their forthcoming Android tablets. Google itself is rumoured to be working with Motorola on its own branded Android tablet.

Variety is the spice
Microsoft CEO Steve Ballmer may have previously dismissed them as a “weird collection of Android machines”, but one advantage of Android tablets is the sheer variety of devices that will shortly be available – as is already the case in the smartphone market, in which Android is enjoying a huge surge in market share. Unlike the iPad, Android tablets will come in all sizes, from the 5‑inch Dell Streak smartphone-cum-tablet, right up to the 15.6-inch Vega from T-Mobile.

Ben Bajarin, director of consumer technology practice at Creative Strategies, told Linux User & Developer: “One major advantage I think [Android] will have is variation in hardware, specifically in form factors. Since so many different manufacturers can use Android, it presents the opportunity for a lot of innovation at the hardware level.”

Jack Gold, director of J Gold Associates, concurred: “I think the biggest thing is the diversity [Android tablets] will represent, giving users the ability to choose what features/functions they want.”

Price will also be a key factor. A survey by the Retrevo website saw 53 per cent of respondents citing a lower price when asked ‘What would make you buy an Android-based tablet over an iPad?’.

Jon Love, business development manager at Clove Technology, commented: “The Android tablets should see success through those users who do not want to be restricted by the Apple OS and pay large sums for hardware and technology which can realistically be acquired at prices more sensible and attractive to the average user who would like to benefit from the new technologies and form factor.”

There may not be as much scope to discount devices on a 3G data contract with network operators as in the smartphone market, however. Rhoda Alexander, director of monitor research at iSuppli, told LUD: “Pricing is going to be interesting to watch, especially for those entrants coming from the phone environment, where they are accustomed to working with service contractors to offset some of the device pricing. With the data limitations on most of those service plans, the majority of users are likely to go with a Wi-Fi only solution, as they have with the iPad, meaning the device providers will have to carry their own weight on the device cost.”

Still, there should be Android tablets to suit all pockets, including budget devices – although you tend to get what you pay for, as Victoria Fodale, senior analyst at ABI Research, cautioned: “Attractive pricing will be important, but not if it reduces the performance too greatly (as we saw with the Augen tablet that was offered by Kmart in the US).” Selling for the amazing price of $150, the Augen Gentouch78 7-inch tablet disappointed. Like some other budget tablets, the main drawback was an unresponsive resistive touch screen rather than the finger-friendly capacitive one on the iPad (and most smartphones).

Android devices need to be of much higher quality than that to compete head-to-head with the iPad, and it’s clear that those from the major OEMs will be. For instance, Samsung’s GT-P1000 will feature a 7-inch, 1024×600 capacitive display and a powerful ARM Cortex-A8 1GHz CPU coupled with a PowerVR GPU.

iPad drawbacks
The Android devices can also target some of the iPad’s weaknesses. While the iPad is an impressive piece of kit, it isn’t without its flaws. And the biggest omission, without doubt, is the lack of Flash video support for web browsing – something that isn’t likely to be addressed by Apple, according to Steve Jobs: “Sometimes you have to pick the things that look like the right horses to ride going forward. And Flash looks like a technology that had its day and is waning. And HTML5 looks like the technology that is really on the ascendancy right now.”

It may well be the case that the growth of HTML5, and its built-in video tag, will eventually make Flash largely redundant, but it hasn’t happened yet and a lot of web video still relies on Adobe’s software. This represents a major opportunity for Android tablets to provide the full internet experience that the iPad cannot, since from version 2.2 (Froyo) onwards, the Android OS incorporates native support for Flash 10.1.

Other iPad weaknesses include the lack of expandable memory, whereas most Android tablets will feature a microSD memory card slot. Instead you have to opt for 16, 32 or 64GB of internal storage. There’s no camera either, not even a front-facing webcam for video chat – as featured on the iPhone 4 for FaceTime. There’s no standard micro-USB or USB port for device or data connection, instead sticking to Apple’s proprietary one. Although the battery will last a good ten hours with normal use, it’s non-removable so you can’t carry a spare and if it wears out, you’ll have to visit an Apple store to have it replaced.

Also, 3G and GPS are only available on some iPad models, costing £100 extra. Finally, there’s the lack of portability of a 9.7-inch device; to address this, Apple is rumoured to be working on a smaller 5- or 7-inch iPad for 2011, according to DigiTimes Research senior analyst, Mingchi Kuo.

As well as targeting the iPad’s weaknesses, the Android tablet market should see further innovation in hardware, including a dual-boot device from ViewSonic. Samsung has also patented a double-sided, dual-screen tablet, while Toshiba might well adapt the folding dual-screen design from its Libretto W100 Windows device.

Continue to page 2…

Click here for more top stories from Linux User & Developer

This article originally appeared in issue 90 of Linux User & Developer magazine. Subscribe and save more than 30% and receive our exclusive money back guarantee – click here to find out more.

What’s your favourite open source project? Tell us and you could will a £500 state-of-the-art VPS package from LCN.com/vps!

There was a time when UNIX desktops were developed by big corporations. It took not just one but many large firms to come together to build a desktop for the UNIX OS. The end result was CDE (Common Desktop Environment), developed jointly by Sun Microsystems, HP, IBM and UNIX Systems Laboratories. To its credit, it was a popular desktop environment used in almost all UNIX systems, but it was (and still is) not even close to being a decent desktop for most users. CDE was announced in June 1993. Windows was already available and CDE looked quite primitive by comparison. In 1996, the KDE project was started, followed a year later by GNOME, and the world of UNIX desktops changed for ever. It was quite surprising back then because neither KDE nor GNOME was a commercial project. Both started as open source, and both shared the same goal: to make Linux the best desktop operating system. But the philosophy was different. The KDE project wasn’t concerned with open source idealism – which is why GNOME was born, to create a desktop environment with fully GPLed software. This philosophical disagreement led to two completely different and innovative desktop environments for Linux.

For your convenience the article has been broken down into a number of sub-sections which weighs up the various pros and cons for GNOME and KDE in various situation for both users and developers. Turn the page to get started…

Want to make sure your applications play nicely on both KDE and GNOME DE’s? Check out our quick guide here…