Winter 2010 Posters/ARM Intro

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Project Name



Arlene Daniel

Our Goal

To enable the current version of Fedora to be used on low-power ARM computer systems. We will do this by setting up the Fedora build system, named Koji, on a cluster of ARM computers. These computers will build an ARM-compatible version of each of the approximately 15,000 Fedora software packages. The Koji-Shadow software will be used to monitor the main Fedora Koji system -- which builds software packages for PCs -- so that every time a new software package is prepared for PCs it will automatically also be built on our Koji system for ARM computers. The resulting packages will be placed in a publicly-accessible repository so that they can be used worldwide.

About The ARM Architecture

ARM chips are the most popular 32-bit RISC (Reduced Instruction Set Computer) microprocessors --the brain of the computer that carries out its most complex functions -- and is mainly used in low power applications -- not much power is needd to operate the device --. Approximately 1.6 billion are being made each year by different manufactures and are sold under a number of different brand names, brands like ARM, StrongARM, Armada, Cortex, OMAP, Sheeva, Snapdragon and XScale to name a few. The chips created are used in devices like cellphones, routers, NAS boxes, embedded controllers, tablets, netbooks and many others.

The ARM Hardware

The devices listed below are some of the devices that use a ARM processor:

   * One Laptop Per Child (OLPC) computers is a subnotebook -- a notebook that is smaller than the average notebook -- that's donated
     to developing countries, with the hope that, every primary school child could have their own laptop to explore the world. The OLPC is
     very inexpensive to produce, costing developers fifty dollars($50) for everyone produced.
   * The Touch Book - developed by Always Innovating -- is a lightweight portable device that has a detachable magnetic keyboard and
   * The SheevaPlug - a plug computer designed to run network-based software devices are some devices that use an ARM processor.

These devices also use a Linux based OS and since Fedora is used on the XO units, having a reliable ARM build of Fedora is increasingly important.

About Fedora

Fedora is an open source operating system using RPM-based -- linux distributions that use a tool to automate the process of installing, upgrading, configuring and removing software packages, built on top of the Linux kernel. Software packages -- are computer software that are stored in an archived format to install programs.-- Archived format -- a compressed format of storing files.-- There are presently over 15000 software packages availabe for download to linux community of users. It is developed and maintained by a community-support -- a group of programmers who contribute to the development of Fedora -- known as the Fedora Project which is sponsored by Red Hat. The Fedora Project's mission is "To lead the advancement of free and open source software and content as a collaborative community." Fedora’s main aim is to be a leader in the use and distribution on software designed as open source-- the source code the proogram is readily available. -- Fedora has a release every six months and a maintenance period of about thirteen months for each of its releases. Fedora 12 was released November 11, 2009 and Fedora 13 has an expected release date of May 18, 2010.

Supported Architecture

Fedora supports two primary architectures:

  i386 - 32-bit Intel/AMD-compatible
  x86_64 - 64-bit Intel/AMD-compatible

There are also a number of secondary archs:

 arm - A widely-used, low-power processor family commonly used for embedded and mobile applications
 ia64 - Itanium
 pa-risc - HP Precision Architecture
 ppc - 32-bit Power PC
 ppc64 - 64-bit Power PC
 s390 - IBM mainframes (including z90 and z9)
 sparc - Sun RISC architecture

Primary architectures are instrumental in the design and development of any fedora release. During the development of a fedora release if any of the primary architecture builds fail, the packages cannot be released. Fedora package maintainers are required to make sure that their package builds properly for this architecture. Users of any linux distrbutions use one of these primary architectures.

Secondary architectures are architectures where the hardware for the secondaries are maintained by the people producing the builds for those secondary architectures. Build failures on secondary architectures are not fatal, unlike builds in the primary architectures, the failure repairs on the secondary architectures are often released several months after the primary ones.

The ARM Architecture

The ARM architecture is increasingly important, but there's a lot more that could be done in terms of update frequency, number of packages successfully built, transparency of process, and integration with the other Fedora build processes.

Fedora policy requires that packages be natively compiled. We use a cluster of ARM hardware and QEMU virtual machines to build the packages natively for ARM.

The baseline ARM CPU architecture that we have chosen to support is ARMv5TE, Little Endian, Soft-Float, EABI. We believe that this provides a nice baseline and that the pre-built packages and root file system images. You should be able to use this on many of the modern ARM CPUs, including XScale, ARM926 and ARM-11, etc.

Although we do not provide such binaries, the sources also lend themselves for building for pre-ARMv5TE hardware. The same is true for big-endian CPUs.

We currently do not plan to provide an installer, ISO images, or a kernel. Unlike in the x86 world, different ARM CPU families require different kernel images. Likewise, it is not entirely clear whether it makes sense to provide an installer or ISO images.

Our Objective

The plan was to set up a Koji builder on a system of eight virtual ARM machines that is based on the CDOT system HongKong. The ARM builders are using QEMU emulation, -- a processor emulator -- which will be replaced by ARM Hardware when it arrives. The ARM Hardware that was purchased was an OpenRD platform. This platform is powered by the fastest ARM architecture available. The platform allows us to create and complete our designs.

The HongKong system also housed a PosegreSQL database and the Koji hub, Koji Web and Kojira. Other components like Apache and Mock also had to be installed on the system.


  • Chris Tyler