Operating systems
BBB up to version A5C and built before May 2014 comes with a preinstalled operating system, namely the Angstrom Linux distribution. Later versions come with the Debian Linux distribution. Texas Instruments provides two releases: an Android and a Linux operating system. All the examples in this book are based on the Ubuntu Linux distribution; however, it is a question of personal taste which Linux distribution you want to use. If you decide to use another distribution, you might have to figure out how to compile your software and install the required packages on your own. There is, however, a chance that packages used throughout this book for Ubuntu might also work with other Linux distributions. Android does not support general Linux software and cannot be used to build a cluster with the means described in this book.
ARMhf images
Linux operating systems are available for a vast variety of different computer platforms such as PowerPC, x86, IA-64, ARM, and many more. An interesting feature of the CPU used on BBBs is the implementation of floating point instructions. This means that mathematical operations based on non-integer values can be executed by hardware rather than software, and thus they are carried out much faster. ARMhf stands for ARM hard float architecture. To make use of this advantage, a special operating system image is used throughout this book, namely the Ubuntu-12.04-armhf image from John Clark.
The Ubuntu 12.04 ARMhf Linux system
The Ubuntu 12.04 Linux distribution, compiled for the ARMhf platform, can be obtained from the home page of John Clark's website at http://www.armhf.com/download/. Please keep in mind that Linux systems and software are updated a lot. If you are not able to get exactly the same software as that used in this book, you can try a newer one or download the version from the download section accompanying this book. You will find more details on how to download and install the operating system in Chapter 2, Building a Beowulf Cluster.
Tip
Downloading the example code
You can download the example code files from your account at http://www.packtpub.com for all the Packt Publishing books you have purchased. If you purchased this book elsewhere, you can visit http://www.packtpub.com/support and register to have the files e-mailed directly to you.
