1066 lines
44 KiB
Text
1066 lines
44 KiB
Text
<!DOCTYPE article PUBLIC "-//FreeBSD//DTD DocBook V4.1-Based Extension//EN" [
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<!ENTITY % articles.ent PUBLIC "-//FreeBSD//ENTITIES DocBook FreeBSD Articles Entity Set//EN">
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%articles.ent;
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]>
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<article>
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<articleinfo>
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<title>Building Products with FreeBSD</title>
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<authorgroup>
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<author>
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<firstname>Joseph</firstname>
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<surname>Koshy</surname>
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<affiliation>
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<orgname>The FreeBSD Project</orgname>
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<address><email>jkoshy@FreeBSD.org</email></address>
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</affiliation>
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</author>
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</authorgroup>
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<pubdate>$FreeBSD$</pubdate>
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<legalnotice id="trademarks" role="trademarks">
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&tm-attrib.freebsd;
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&tm-attrib.general;
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</legalnotice>
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<abstract>
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<title>Abstract</title>
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<para>The FreeBSD project is a worldwide, voluntary, and
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collaborative project, which develops a portable and high-quality
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operating system. The FreeBSD project distributes the source
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code for its product under a liberal license, with the
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intention of encouraging the use of its code. Collaborating
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with the FreeBSD project can help organizations reduce their
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time to market, reduce engineering costs and improve their
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product quality.</para>
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<para>This article examines the issues in using FreeBSD code in
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appliances and software products. It highlights the
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characteristics of FreeBSD that make it an excellent substrate
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for product development. The article concludes by suggesting a
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few <quote>best practices</quote> for organizations
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collaborating with the FreeBSD project.</para>
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</abstract>
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</articleinfo>
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<sect1 id="introduction">
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<title>Introduction</title>
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<para>FreeBSD today is well-known as a high-performance server
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operating system. It is deployed on millions of web servers and
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internet-facing hosts worldwide. FreeBSD code also forms an
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integral part of many products, ranging from appliances such as
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network routers, firewalls, and storage devices, to personal
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computers. Portions of FreeBSD have also been used in
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commercial shrink-wrapped software (see
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<xref linkend="freebsd-intro">).</para>
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<para>In this article we look at the <ulink
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url="&url.base;/">FreeBSD project</ulink> as a software
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engineering resource—as a collection of building blocks
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and processes which you can use to build products.</para>
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<para>While FreeBSD's source is distributed freely to the public,
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to fully enjoy the benefits of the project's work, organizations
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need to <emphasis>collaborate</emphasis> with the project. In
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subsequent sections of this article we discuss effective means
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of collaboration with the project and the pitfalls that need to
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be avoided while doing so.</para>
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<formalpara>
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<title>Caveat Reader</title>
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<para>The author believes that the characteristics of the FreeBSD
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Project listed in this article were substantially true at the
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time the article was conceived and written (2005). However, the
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reader should keep in mind that the practices and processes used
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by open-source communities can change over time, and that the information
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in this article should therefore be taken as indicative rather
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than normative.</para>
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</formalpara>
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<sect2>
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<title>Target Audience</title>
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<para>This document would be of interest to the following broad
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groups of people:</para>
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<itemizedlist>
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<listitem>
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<simpara>Decision makers in product companies looking at
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ways to improve their product quality, reduce their time
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to market and lower engineering costs in the long
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term.</simpara>
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</listitem>
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<listitem>
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<simpara>Technology consultants looking for best-practices
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in leveraging <quote>open-source</quote>.</simpara>
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</listitem>
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<listitem>
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<simpara>Industry observers interested in understanding the
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dynamics of open-source projects.</simpara>
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</listitem>
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<listitem>
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<simpara>Software developers seeking to use FreeBSD and
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looking for ways to contribute back.</simpara>
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</listitem>
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</itemizedlist>
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</sect2>
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<sect2>
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<title>Article Goals</title>
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<para>After reading this article you should have:</para>
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<itemizedlist>
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<listitem>
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<simpara>An understanding of the goals of the FreeBSD
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Project and its organizational structure.</simpara>
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</listitem>
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<listitem>
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<simpara>An overview of the available technology in the
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project.</simpara>
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</listitem>
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<listitem>
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<simpara>An understanding of its development model and
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release engineering processes.</simpara>
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</listitem>
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<listitem>
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<simpara>An understanding of how conventional corporate
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software development processes differ from that used in
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the FreeBSD project.</simpara>
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</listitem>
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<listitem>
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<simpara>Awareness of the communication channels used by the
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project and the level of transparency you can
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expect.</simpara>
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</listitem>
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<listitem>
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<simpara>Awareness of optimal ways of working with the
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project—how best to reduce engineering costs,
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improve time to market, manage security vulnerabilities,
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and preserve future compatibility with your product as the
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FreeBSD project evolves.</simpara>
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</listitem>
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</itemizedlist>
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</sect2>
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<sect2>
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<title>Article Structure</title>
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<para>The rest of the article is structured as follows:</para>
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<itemizedlist>
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<listitem>
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<simpara><xref linkend="freebsd-intro"> introduces the
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FreeBSD project, explores its organizational structure,
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key technologies and release engineering
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processes.</simpara>
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</listitem>
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<listitem>
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<simpara><xref linkend="freebsd-collaboration"> describes
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ways to collaborate with the FreeBSD project. It examines
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common pitfalls encountered by corporates working with
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voluntary projects like FreeBSD.</simpara>
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</listitem>
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<listitem>
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<simpara><xref linkend="conclusion"> concludes.</simpara>
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</listitem>
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</itemizedlist>
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</sect2>
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</sect1>
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<sect1 id="freebsd-intro">
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<title>FreeBSD as a set of building blocks</title>
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<para>FreeBSD makes an excellent foundation on which to build
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products:</para>
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<itemizedlist>
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<listitem>
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<simpara>FreeBSD source code is distributed under a liberal
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BSD license facilitating its adoption in commercial products
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<citation>Mon2005</citation> with minimum hassle.</simpara>
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</listitem>
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<listitem>
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<simpara>The FreeBSD project has excellent engineering
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practices that can be leveraged.</simpara>
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</listitem>
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<listitem>
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<simpara>The project offers exceptional transparency into its
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workings, allowing organizations using its code to plan
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effectively for the future.</simpara>
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</listitem>
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<listitem>
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<simpara>The culture of the FreeBSD project, carried over from
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the Computer Science Research Group at The University of
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California, Berkeley <citation>McKu1999-1</citation>,
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fosters high-quality work. Some features in FreeBSD define
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the state of the art.</simpara>
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</listitem>
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</itemizedlist>
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<simpara><citation>GoldGab2005</citation> examines the business
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reasons for using open-source in greater detail. For
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organizations, the benefits of using FreeBSD components in their
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products include a shorter time to market, lower development
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costs and lower development risks. </simpara>
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<sect2>
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<title>Building with FreeBSD</title>
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<simpara>Here are a few ways organizations have used
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FreeBSD:</simpara>
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<itemizedlist>
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<listitem>
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<simpara>As an upstream source for tested code for libraries
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and utilities.</simpara>
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<simpara>By being <quote>downstream</quote> of the project,
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organizations leverage the new features, bug fixes and
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testing that the upstream code receives.</simpara>
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</listitem>
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<listitem>
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<simpara>As an embedded OS (for example, for an OEM router
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and firewall device). In this model, organizations use a
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customized FreeBSD kernel and application program set
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along with a proprietary management layer for their
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device. OEMs benefit from new hardware support being added
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by the FreeBSD project upstream, and from the testing that
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the base system receives.</simpara>
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<simpara>FreeBSD ships with a self-hosting development
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environment that allows easy creation of such
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configurations.</simpara>
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</listitem>
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<listitem>
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<simpara>As a Unix compatible environment for the management
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functions of high-end storage and networking devices,
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running on a separate processor <quote>blade</quote>.</simpara>
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<simpara>FreeBSD provides the tools for creating dedicated
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OS and application program images. Its implementation of
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a BSD unix API is mature and tested. FreeBSD can also
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provide a stable cross-development environment for the
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other components of the high-end device.</simpara>
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</listitem>
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<listitem>
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<simpara>As a vehicle to get widespread testing and support
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from a worldwide team of developers for non-critical
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<quote>intellectual property</quote>.</simpara>
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<simpara>In this model, organizations contribute useful
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infrastructural frameworks to the FreeBSD project (for
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example, see &man.netgraph.3;). The widespread
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exposure that the code gets helps to quickly identify
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performance issues and bugs. The involvement of
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top-notch developers also leads to useful extensions to
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the infrastructure that the contributing organization also
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benefits from.</simpara>
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</listitem>
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<listitem>
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<simpara>As a development environment supporting
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cross-development for embedded OSes like <ulink
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url="http://www.rtems.com/">RTEMS</ulink> and <ulink
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url="http://ecos.sourceware.org/">eCOS</ulink>.</simpara>
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<simpara>There are many full-fledged development environments
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in the &os.numports;-strong collection of applications ported and
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packaged with FreeBSD.</simpara>
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</listitem>
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<listitem>
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<simpara>As a way to support a Unix-like API in an otherwise
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proprietary OS, increasing its palatability for
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application developers.</simpara>
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<simpara>Here parts of FreeBSD's kernel and application
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programs are <quote>ported</quote> to run alongside
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other tasks in the proprietary OS. The availability of a
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stable and well tested <trademark>Unix</trademark> API
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implementation can reduce the effort needed to port
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popular applications to the proprietary OS. As FreeBSD
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ships with high-quality documentation for its internals
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and has effective vulnerability management and release
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engineering processes, the costs of keeping upto-date are
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kept low.</simpara>
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</listitem>
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</itemizedlist>
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</sect2>
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<sect2 id="freebsd-technologies">
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<title>Technologies</title>
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<para>There are a large number of technologies supported by the
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FreeBSD project. A selection of these are listed
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below:</para>
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<itemizedlist>
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<listitem>
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<simpara>A complete system that can cross-host itself for
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the following architectures: alpha (up to &os; version 6.X), amd64, ia64, i386,
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sparc64, powerpc (see &man.build.7;).</simpara>
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</listitem>
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<listitem>
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<simpara>Support for the following technologies, protocols
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and standards: <!-- Keyword soup. Urk. -->
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<acronym>ATA</acronym>, <acronym>ATAPI</acronym>,
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<acronym>ATM</acronym>, <trademark>Bluetooth</trademark>,
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<acronym>CAM</acronym>, <trademark>CardBus</trademark>,
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<acronym>DHCP</acronym>, <acronym>DNS</acronym>,
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<trademark>EISA</trademark>,
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<trademark>Ethernet</trademark>, <acronym>FDDI</acronym>,
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Fibre Channel, <acronym>GPIB</acronym>, IEEE 1394, IPv4,
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IPv6, <acronym>IPSEC</acronym>,
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<trademark>IPX</trademark>, <acronym>ISDN</acronym>,
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<acronym>MAC</acronym>, <acronym>NIS</acronym>,
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<acronym>NFS</acronym>, OpenSSH, <acronym>OPIE</acronym>,
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<acronym>PAM</acronym>, <trademark>PCI</trademark>,
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<acronym>PCMCIA</acronym>, <trademark>POSIX</trademark>,
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<acronym>PnP</acronym>, <acronym>RAID</acronym>,
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<acronym>RPC</acronym>, <acronym>SATA</acronym>,
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<acronym>SCSI</acronym>, <acronym>SMB</acronym>,
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<acronym>TCP</acronym>, <acronym>USB</acronym>,
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<acronym>VESA</acronym>, <acronym>VLAN</acronym>,
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<acronym>VLB</acronym>,
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<trademark>WebNFS</trademark>.</simpara>
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</listitem>
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<listitem>
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<simpara>A modular symmetric multiprocessing capable kernel,
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with loadable kernel modules and a flexible and easy to
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use configuration system.</simpara>
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</listitem>
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<listitem>
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<simpara>Support for emulation of
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<trademark>Linux</trademark> and SVR4 binaries at near
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machine speeds. Support for binary
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<trademark>Windows</trademark> (<acronym>NDIS</acronym>)
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network drivers.</simpara>
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</listitem>
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<listitem>
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<simpara>Libraries for many programming tasks: archivers,
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FTP and HTTP support, thread support, in addition to a
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full <trademark>POSIX</trademark> like programming
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environment.</simpara>
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</listitem>
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<listitem>
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<simpara>Advanced security features: Mandatory Access
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Control (&man.mac.9;), jails (&man.jail.2;),
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<acronym>ACL</acronym>s, and in-kernel
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cryptographic device support.</simpara>
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</listitem>
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<listitem>
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<simpara>Advanced networking features: firewall-ing, QoS
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management, high-performance TCP/IP networking with
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support for many advanced features.</simpara>
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<simpara>FreeBSD's in-kernel Netgraph (&man.netgraph.4;)
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framework allows kernel networking modules to be connected
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together in flexible ways.</simpara>
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</listitem>
|
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<listitem>
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<simpara>Support for advanced storage technologies: Fibre
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Channel, <acronym>SCSI</acronym>, software and hardware
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RAID, <acronym>ATA</acronym> and
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<acronym>SATA</acronym>.</simpara>
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<simpara>FreeBSD supports a number of filesystems, and its
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native UFS2 filesystem supports soft updates, snapshots and
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very large filesystem sizes (16TB per filesystem)
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<citation>McKu1999</citation>.</simpara>
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<simpara>FreeBSD's in-kernel <acronym>GEOM</acronym> (&man.geom.4;)
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framework allows kernel storage modules to be
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composed in flexible ways.</simpara>
|
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</listitem>
|
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<listitem>
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<simpara>Over &os.numports; ported applications, both commercial
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and open-source, managed via the FreeBSD ports
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collection.</simpara>
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</listitem>
|
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</itemizedlist>
|
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</sect2>
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<sect2>
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<title>Organizational Structure</title>
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<para>FreeBSD's organizational structure is
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non-hierarchical.</para>
|
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<para>There are essentially two kinds of contributors to
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FreeBSD, general users of FreeBSD, and developers with write
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access (known as <firstterm>committers</firstterm> in the
|
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jargon) to the source base.</para>
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<para>There are many thousands of contributors in the first
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group; the vast majority of contributions to FreeBSD come from
|
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individuals in this group. Commit rights (write access) to
|
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the repository are granted to individuals who contribute
|
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consistently to the project. Commit rights come with
|
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additional responsibilities, and new committers are assigned
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mentors to help them learn the ropes.</para>
|
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<figure>
|
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<title>FreeBSD Organization</title>
|
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<mediaobject>
|
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<imageobject>
|
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<imagedata fileref="freebsd-organization" format="PIC">
|
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</imageobject>
|
|
</mediaobject>
|
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</figure>
|
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|
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<para>Conflict resolution is performed by a nine member
|
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<quote>Core Team</quote> that is elected from the group of
|
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committers.</para>
|
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|
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<para>FreeBSD does not have <quote>corporate</quote> committers.
|
|
Individual committers are required to take responsibility for
|
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the changes they introduce to the code. The <ulink
|
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url="&url.articles.committers-guide;">FreeBSD Committer's
|
|
guide</ulink> <citation>ComGuide</citation> documents the
|
|
rules and responsibilities for committers.</para>
|
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|
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<para>FreeBSD's project model is examined in detail in
|
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<citation>Nik2005</citation>.</para>
|
|
</sect2>
|
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|
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<sect2>
|
|
<title>FreeBSD Release Engineering Processes</title>
|
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|
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<para>FreeBSD's release engineering processes play a major role
|
|
in ensuring that its released versions are of a high quality.
|
|
At any point of time, FreeBSD's volunteers support multiple
|
|
code lines (<xref linkend="fig-freebsd-branches">):</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<simpara>New features and disruptive code enters on the
|
|
development branch, also known as the
|
|
<firstterm>-CURRENT</firstterm> branch.</simpara>
|
|
</listitem>
|
|
<listitem>
|
|
<simpara><firstterm>-STABLE</firstterm> branches are code
|
|
lines that are branched from HEAD at regular intervals.
|
|
Only tested code is allowed onto a -STABLE branch. New
|
|
features are allowed once they have been tested and
|
|
stabilized in the -CURRENT branch.</simpara>
|
|
</listitem>
|
|
<listitem>
|
|
<simpara><firstterm>-RELEASE</firstterm> branches are
|
|
maintained by the FreeBSD security team. Only bug fixes
|
|
for critical issues are permitted onto -RELEASE
|
|
branches.</simpara>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<figure id="fig-freebsd-branches">
|
|
<title>FreeBSD Release Branches</title>
|
|
<mediaobject>
|
|
<imageobject>
|
|
<imagedata fileref="freebsd-branches" format="EPS">
|
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</imageobject>
|
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</mediaobject>
|
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</figure>
|
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|
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<para>Code lines are kept alive for as long as there is user and
|
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developer interest in them.</para>
|
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|
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<para>Machine architectures are grouped into
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<quote>tiers</quote>; <firstterm>Tier 1</firstterm>
|
|
architectures are fully supported by the project's release
|
|
engineering and security teams, <firstterm>Tier 2</firstterm>
|
|
architectures are supported on a best effort basis, and
|
|
experimental architectures comprise <firstterm>Tier
|
|
3</firstterm>. The list of <ulink
|
|
url="&url.articles.committers-guide;/archs.html">supported
|
|
architectures</ulink> is part of the FreeBSD documentation
|
|
collection.</para>
|
|
|
|
<para>The release engineering team publishes a <ulink
|
|
url="&url.base;/releng/">road map</ulink> for future
|
|
releases of FreeBSD on the project's web site. The dates laid
|
|
down in the road map are not deadlines; FreeBSD is released
|
|
when its code and documentation are ready.</para>
|
|
|
|
<para>FreeBSD's release engineering processes are described in
|
|
<citation>RelEngDoc</citation>.</para>
|
|
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="freebsd-collaboration">
|
|
<title>Collaborating with FreeBSD</title>
|
|
|
|
<para>Open-source projects like FreeBSD offer finished code of a
|
|
very high quality <citation>Cov2005</citation>. Previous
|
|
studies have examined the effect of source code availability on
|
|
software development <citation>Com2004</citation>.</para>
|
|
|
|
<para>While access to quality source code can reduce the cost of
|
|
initial development, in the long-term the costs of managing
|
|
change begin to dominate. As computing environments change over
|
|
the years and new security vulnerabilities are discovered, your
|
|
product too needs to change and adapt. Using open-source code is
|
|
best viewed not as a one-off activity, but as an
|
|
<emphasis>ongoing process</emphasis>. The best projects to
|
|
collaborate with are the ones that are
|
|
<emphasis>live</emphasis>; i.e., with an active community, clear
|
|
goals and a transparent working style.</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<simpara>FreeBSD has an active developer community around it.
|
|
At the time of writing there are many thousands of
|
|
contributors from every populated continent in the world and
|
|
over 300 individuals with write access to the project's
|
|
source repositories.</simpara>
|
|
</listitem>
|
|
<listitem>
|
|
<simpara>The goals of the FreeBSD project are
|
|
<citation>Hub1994</citation>:
|
|
<itemizedlist spacing="compact">
|
|
<listitem>
|
|
<simpara>To develop a high-quality operating system for
|
|
popular computer hardware, and,</simpara>
|
|
</listitem>
|
|
<listitem>
|
|
<simpara>To make our work available to all under a liberal
|
|
license.</simpara>
|
|
</listitem>
|
|
</itemizedlist>
|
|
</listitem>
|
|
<listitem>
|
|
<simpara>FreeBSD enjoys an open and transparent working
|
|
culture. Nearly all discussion in the project happens by
|
|
email, on <ulink url="&a.mailman.listinfo;">public mailing
|
|
lists</ulink> that are also archived for posterity. The
|
|
project's policies are <ulink
|
|
url="&url.base;/internal/policies.html">documented</ulink>
|
|
and maintained under revision control. Participation in the
|
|
project is open to all.</simpara>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<sect2 id="freebsd-org">
|
|
<title>Understanding FreeBSD culture</title>
|
|
|
|
<para>To be able to work effectively with the FreeBSD project,
|
|
you need to understand the project's culture.</para>
|
|
|
|
<para>Volunteer driven projects operate under different rules
|
|
than for-profit corporates. A common mistake that companies
|
|
make when venturing into the open-source world is that of
|
|
underplaying these differences.</para>
|
|
|
|
<!-- XXX using <formalpara> constructs is clunky, but I like using
|
|
<variablelist> even less -->
|
|
<formalpara>
|
|
<title>Motivation</title>
|
|
|
|
<para>Most contributions to FreeBSD are done voluntarily
|
|
without monetary rewards entering the picture. The factors
|
|
that motivate individuals are complex, ranging from
|
|
altruism, to an interest in solving the kinds of problems
|
|
that FreeBSD attempts to solve. In this environment,
|
|
<quote>elegance is never optional</quote>
|
|
<citation>Nor1993</citation>.</para>
|
|
</formalpara>
|
|
|
|
<formalpara>
|
|
<title>The Long Term View</title>
|
|
<para>FreeBSD traces its roots back nearly twenty years to the
|
|
work of the Computer Science Research Group at the
|
|
University of California Berkeley.<footnote>
|
|
<simpara>FreeBSD's <ulink
|
|
url="http://cvsweb.freebsd.org/">source
|
|
repository</ulink> contains a history of the project
|
|
since its inception, and there are <ulink
|
|
url="http://www.mckusick.com/csrg/">CDROMs
|
|
available</ulink> that contain earlier code from the
|
|
CSRG.</simpara>
|
|
</footnote> A number of the original CSRG developers remain
|
|
associated with the project.</para>
|
|
</formalpara>
|
|
|
|
<para>The project values long-term perspectives
|
|
<citation>Nor2001</citation>. A frequent acronym encountered
|
|
in the project is <acronym>DTRT</acronym>, which stands for
|
|
<quote>Do The Right Thing</quote>.</para>
|
|
|
|
<formalpara>
|
|
<title>Development Processes</title>
|
|
<para>Computer programs are tools for communication: at one
|
|
level programmers communicate their intentions using a
|
|
precise notation to a tool (a compiler) that translates
|
|
their instructions to executable code. At another level,
|
|
the same notation is used for communication of intent
|
|
between two programmers.</para>
|
|
</formalpara>
|
|
|
|
<para>Formal specifications and design documents are seldom used
|
|
in the project. Clear and well-written code and well-written
|
|
change logs (<xref linkend="fig-change-log">) are used in
|
|
their place. FreeBSD development happens by <quote>rough
|
|
consensus and running code</quote>
|
|
<citation>Carp1996</citation>.</para>
|
|
|
|
<figure id="fig-change-log">
|
|
<title>A sample change log entry</title>
|
|
<programlisting>
|
|
bde 2005-10-29 16:34:50 UTC
|
|
|
|
FreeBSD src repository
|
|
|
|
Modified files:
|
|
lib/msun/src e_rem_pio2f.c
|
|
Log:
|
|
Use double precision to simplify and optimize arg reduction for small
|
|
and medium size args too: instead of conditionally subtracting a float
|
|
17+24, 17+17+24 or 17+17+17+24 bit approximation to pi/2, always
|
|
subtract a double 33+53 bit one. The float version is now closer to
|
|
the double version than to old versions of itself — it uses the same
|
|
33+53 bit approximation as the simplest cases in the double version,
|
|
and where the float version had to switch to the slow general case at
|
|
|x| == 2^7*pi/2, it now switches at |x| == 2^19*pi/2 the same as the
|
|
double version.
|
|
|
|
This speeds up arg reduction by a factor of 2 for |x| between 3*pi/4 and
|
|
2^7*pi/4, and by a factor of 7 for |x| between 2^7*pi/4 and 2^19*pi/4.
|
|
|
|
Revision Changes Path
|
|
1.14 +22 -97 src/lib/msun/src/e_rem_pio2f.c
|
|
</programlisting>
|
|
</figure>
|
|
|
|
<simpara>Communication between programmers is enhanced by the
|
|
use of a common coding standard &man.style.9;.</simpara>
|
|
|
|
<formalpara>
|
|
<title>Communication Channels</title>
|
|
<para>FreeBSD's contributors are spread across the world.
|
|
Email (and to a lesser extent, IRC) is the preferred means
|
|
of communication in the project.</para>
|
|
</formalpara>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Best Practices for collaborating with the FreeBSD
|
|
project</title>
|
|
|
|
<para>We now look at a few best practices for making the best
|
|
use of FreeBSD in product development.</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term>Plan for the long term</term>
|
|
<listitem>
|
|
<para>Setup processes that help in tracking the development of
|
|
FreeBSD. For example:</para>
|
|
<formalpara>
|
|
<title>Track FreeBSD source code</title>
|
|
<para>The project makes it easy to mirror its CVS
|
|
repository using <ulink
|
|
url="&url.articles.cvsup-advanced;"><!--
|
|
--><application>CVSup</application></ulink>. Having
|
|
the complete history of the source is useful when
|
|
debugging complex problems and offers valuable insight
|
|
into the intentions of the original developers. Use a
|
|
capable source control system that allows you to
|
|
easily merge changes between the upstream FreeBSD code
|
|
base and your own in-house code.</para>
|
|
</formalpara>
|
|
<para><xref linkend="fig-cvs-annotate"> shows a portion of
|
|
an annotated listing of the file referenced by the
|
|
change log in <xref linkend="fig-change-log">. The
|
|
ancestry of each line of the source is clearly visible.
|
|
Annotated listings showing the history of every file
|
|
that is part of FreeBSD are <ulink
|
|
url="http://cvsweb.freebsd.org/">available on the
|
|
web</ulink>.</para>
|
|
<figure id="fig-cvs-annotate">
|
|
<title>An annotated source listing generated using <command>cvs annotate</command></title>
|
|
<programlisting>
|
|
#LINE #REV #WHO #DATE #TEXT
|
|
|
|
62 1.1 (jkh 19-Aug-94): int32_t __ieee754_rem_pio2f(float x, float *y)
|
|
63 1.1 (jkh 19-Aug-94): {
|
|
64 1.14 (bde 29-Oct-05): double z,w,t,r,fn;
|
|
65 1.13 (bde 29-Oct-05): double tx[3];
|
|
66 1.14 (bde 29-Oct-05): int32_t e0,i,nx,n,ix,hx;
|
|
67 1.1 (jkh 19-Aug-94):
|
|
68 1.1 (jkh 19-Aug-94): GET_FLOAT_WORD(hx,x);
|
|
69 1.1 (jkh 19-Aug-94): ix = hx&0x7fffffff;
|
|
70 1.1 (jkh 19-Aug-94): if(ix<=0x3f490fd8) /* |x| ~<= pi/4 , no need for reduction */
|
|
71 1.1 (jkh 19-Aug-94): {y[0] = x; y[1] = 0; return 0;}
|
|
72 1.14 (bde 29-Oct-05): /* 33+53 bit pi is good enough for special and medium size cases */
|
|
73 1.2 (bde 07-Apr-95): if(ix<0x4016cbe4) { /* |x| < 3pi/4, special case with n=+-1 */
|
|
74 1.14 (bde 29-Oct-05): if(hx>0) {
|
|
75 1.15 (bde 06-Nov-05): z = x - pio2;
|
|
76 1.15 (bde 06-Nov-05): n = 1;
|
|
77 1.15 (bde 06-Nov-05): } else {
|
|
78 1.15 (bde 06-Nov-05): z = x + pio2;
|
|
79 1.15 (bde 06-Nov-05): n = 3;
|
|
80 1.9 (bde 08-Oct-05): }
|
|
81 1.15 (bde 06-Nov-05): y[0] = z;
|
|
82 1.15 (bde 06-Nov-05): y[1] = z - y[0];
|
|
83 1.15 (bde 06-Nov-05): return n;
|
|
84 1.15 (bde 06-Nov-05): }
|
|
85 1.15 (bde 06-Nov-05): if(ix<0x407b53d1) { /* |x| < 5*pi/4, special case with n=+-2 */
|
|
</programlisting>
|
|
</figure>
|
|
|
|
<formalpara>
|
|
<title>Use a gatekeeper</title>
|
|
<para>Appoint a <firstterm>gatekeeper</firstterm> to
|
|
monitor FreeBSD development, to keep an eye out for
|
|
changes that could potentially impact your
|
|
products.</para>
|
|
</formalpara>
|
|
<formalpara>
|
|
<title>Report bugs upstream</title>
|
|
<para>If you notice bug in the FreeBSD code that you are
|
|
using, file a <ulink url="&url.base;/send-pr.html">bug
|
|
report</ulink>. This step helps ensure that you do
|
|
not have to fix the bug the next time you take a code
|
|
drop from upstream.</para>
|
|
</formalpara>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>Leverage FreeBSD's release engineering efforts</term>
|
|
<listitem>
|
|
<simpara>Use code from a -STABLE development branch of
|
|
FreeBSD. These development branches are formally
|
|
supported by FreeBSD's release engineering and security
|
|
teams and comprise of tested code.
|
|
</simpara>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>Donate code to reduce costs</term>
|
|
<listitem>
|
|
<simpara>A major proportion of the costs associated with
|
|
developing products is that of doing maintenance. By
|
|
donating non-critical code to the project, you benefit
|
|
by having your code see much wider exposure than it
|
|
would otherwise get. This in turn leads to more bugs
|
|
and security vulnerabilities being flushed out and
|
|
performance anomalies being identified and fixed.
|
|
</simpara>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>Get support effectively</term>
|
|
<listitem>
|
|
<simpara>For products with tight deadlines, it is
|
|
recommended that you hire or enter into a consulting
|
|
agreement with a developer or firm with FreeBSD
|
|
experience. The &a.jobs; is a useful communication
|
|
channel to find talent. The FreeBSD project maintains a
|
|
<ulink
|
|
url="&url.base;/commercial/consult_bycat.html">gallery
|
|
of consultants and consulting firms</ulink>
|
|
undertaking FreeBSD work. The <ulink
|
|
url="http://www.bsdcertification.org/">BSD
|
|
Certification Group</ulink> offers certification for
|
|
all the major BSD derived OSes.</simpara>
|
|
|
|
<simpara>For less critical needs, you can ask for help on
|
|
the <ulink
|
|
url="http://lists.FreeBSD.org/mailman/listinfo">project
|
|
mailing lists</ulink>. A useful guide to follow when
|
|
asking for help is given in
|
|
<citation>Ray2004</citation>.
|
|
</simpara>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>Publicize your involvement</term>
|
|
<listitem>
|
|
<simpara>You are not required to publicize your use of
|
|
FreeBSD, but doing so helps both your effort as well as
|
|
that of the project.</simpara>
|
|
<simpara>Letting the FreeBSD community know that your
|
|
company uses FreeBSD helps improve your chances of
|
|
attracting high quality talent. A large roster of
|
|
support for FreeBSD also means more mind share for it
|
|
among developers. This in turn yields a healthier
|
|
foundation for your future.</simpara>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>Support FreeBSD developers</term>
|
|
<listitem>
|
|
<simpara>Sometimes the most direct way to get a desired
|
|
feature into FreeBSD is to support a developer who is
|
|
already looking at a related problem. Help can range
|
|
from hardware donations to direct financial assistance.
|
|
In some countries, donations to the FreeBSD project
|
|
enjoy tax benefits. The project has a dedicated <ulink
|
|
url="&url.base;/donations/">donations liaison</ulink>
|
|
to assist donors. The project also maintains a web page
|
|
where developers <ulink
|
|
url="&url.base;/donations/wantlist.html">list their
|
|
needs</ulink>.
|
|
</simpara>
|
|
<simpara>As a policy the FreeBSD project <ulink
|
|
url="&url.articles.contributors;">acknowledges</ulink>
|
|
all contributions received on its web site.</simpara>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="conclusion">
|
|
<title>Conclusion</title>
|
|
<para>The FreeBSD project's goals are to create and give away the
|
|
source code for a high-quality operating system. By working
|
|
with the FreeBSD project you can reduce development costs and
|
|
improve your time to market in a number of product development
|
|
scenarios.</para>
|
|
<para>We examined the characteristics of the FreeBSD project that
|
|
make it an excellent choice for being part of an organization's
|
|
product strategy. We then looked at the prevailing culture of
|
|
the project and examined effective ways of interacting with its
|
|
developers. The article concluded with a list of best-practices
|
|
that could help organizations collaborating with the
|
|
project.</para>
|
|
</sect1>
|
|
|
|
<bibliography>
|
|
<biblioentry>
|
|
<abbrev>Carp1996</abbrev>
|
|
<citetitle><ulink url="http://www.ietf.org/rfc/rfc1958.txt">The
|
|
Architectural Principles of the Internet</ulink></citetitle>
|
|
<author>
|
|
<firstname>B.</firstname>
|
|
<surname>Carpenter</surname>
|
|
<affiliation>
|
|
<orgname>The Internet Architecture Board</orgname>
|
|
</affiliation>
|
|
</author>
|
|
<copyright>
|
|
<year>1996</year>
|
|
</copyright>
|
|
</biblioentry>
|
|
<biblioentry xreflabel="Com2004">
|
|
<abbrev>Com2004</abbrev>
|
|
<citetitle><ulink
|
|
url="http://csdl.computer.org/comp/mags/so/2004/01/s1028.pdf">How
|
|
is Open-Source Affecting Software
|
|
Development?</ulink></citetitle>
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>Diomidis</firstname>
|
|
<surname>Spinellis</surname>
|
|
</author>
|
|
<author>
|
|
<firstname>Clemens</firstname>
|
|
<surname>Szyperski</surname>
|
|
</author>
|
|
</authorgroup>
|
|
<title>IEEE Computer</title>
|
|
<copyright>
|
|
<year>Jan/Feb 2004</year>
|
|
</copyright>
|
|
<publisher>
|
|
<publishername>IEEE Computer Society</publishername>
|
|
</publisher>
|
|
</biblioentry>
|
|
<biblioentry>
|
|
<abbrev>ComGuide</abbrev>
|
|
<citetitle><ulink
|
|
url="&url.articles.committers-guide;">Committer's
|
|
Guide</ulink></citetitle>
|
|
<authorgroup>
|
|
<corpauthor>The FreeBSD Project</corpauthor>
|
|
</authorgroup>
|
|
<copyright>
|
|
<year>2005</year>
|
|
</copyright>
|
|
</biblioentry>
|
|
<biblioentry>
|
|
<abbrev>Cov2005</abbrev>
|
|
<citetitle><ulink
|
|
url="http://www.coverity.com/news/nf_news_06_27_05_story_9.html">Coverity
|
|
study on kernel security holes in Linux and FreeBSD</ulink></citetitle>
|
|
<authorgroup>
|
|
<corpauthor>Coverity Inc.</corpauthor>
|
|
</authorgroup>
|
|
<copyright>
|
|
<year>2005</year>
|
|
</copyright>
|
|
</biblioentry>
|
|
<biblioentry>
|
|
<abbrev>GoldGab2005</abbrev> <citetitle><ulink
|
|
url="http://dreamsongs.com/IHE/IHE.html">Innovation Happens
|
|
Elsewhere: Open Source as Business Strategy</ulink></citetitle>
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>Ron</firstname>
|
|
<surname>Goldman</surname>
|
|
</author>
|
|
<author>
|
|
<firstname>Richard</firstname>
|
|
<surname>Gabriel</surname>
|
|
</author>
|
|
</authorgroup>
|
|
<copyright>
|
|
<year>2005</year>
|
|
</copyright>
|
|
<isbn>ISBN 1558608893</isbn>
|
|
<publisher>
|
|
<publishername>Morgan-Kaufmann</publishername>
|
|
</publisher>
|
|
</biblioentry>
|
|
<biblioentry xreflabel="Hub1994">
|
|
<!-- XXX Get the date of this article right -->
|
|
<abbrev>Hub1994</abbrev>
|
|
<citetitle><ulink url="&url.articles.contributing;">Contributing
|
|
to the FreeBSD Project</ulink></citetitle>
|
|
<author>
|
|
<firstname>Jordan</firstname>
|
|
<surname>Hubbard</surname>
|
|
</author>
|
|
<copyright>
|
|
<year>1994—2005</year>
|
|
</copyright>
|
|
<publisher>
|
|
<publishername>The FreeBSD Project</publishername>
|
|
</publisher>
|
|
</biblioentry>
|
|
<biblioentry>
|
|
<abbrev>McKu1999</abbrev>
|
|
<citetitle><ulink
|
|
url="http://www.usenix.org/publications/library/proceedings/usenix99/mckusick.html">Soft
|
|
Updates: A Technique for Eliminating Most Synchronous Writes
|
|
in the Fast Filesystem</ulink></citetitle>
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>Kirk</firstname>
|
|
<surname>McKusick</surname>
|
|
</author>
|
|
<author>
|
|
<firstname>Gregory</firstname>
|
|
<surname>Ganger</surname>
|
|
</author>
|
|
</authorgroup>
|
|
<confgroup>
|
|
<conftitle>USENIX Annual Technical Conference</conftitle>
|
|
</confgroup>
|
|
<copyright>
|
|
<year>1999</year>
|
|
</copyright>
|
|
</biblioentry>
|
|
<biblioentry>
|
|
<abbrev>McKu1999-1</abbrev>
|
|
<citetitle><ulink
|
|
url="http://www.oreilly.com/catalog/opensources/book/kirkmck.html"
|
|
>Twenty Years of Berkeley Unix: From AT&T-Owned to
|
|
Freely Redistributable</ulink></citetitle>
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>Marshall Kirk</firstname>
|
|
<surname>McKusick</surname>
|
|
</author>
|
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