[287ea55] | 1 | <?xml version="1.0" encoding="ISO-8859-1"?>
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| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
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| 3 | <!ENTITY % general-entities SYSTEM "../general.ent">
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| 4 | %general-entities;
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| 5 | ]>
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| 6 | <sect1 id="pre-audience">
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| 7 | <title>Audience</title>
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| 8 | <?dbhtml filename="audience.html"?>
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| 9 |
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[ee45b2ee] | 10 | <para>There are many reasons why somebody would want to read this
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| 11 | book. The principle reason being to install a Linux system straight
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| 12 | from the source code. A question many people raise is, <quote>why go
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| 13 | through all the hassle of manually building a Linux system from
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| 14 | scratch when you can just download and install an existing
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| 15 | one?</quote> That is a good question and is the impetus for this
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| 16 | section of the book.</para>
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| 17 |
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| 18 | <para>One important reason for LFS's existence is to help people learn
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| 19 | how a Linux system works from the inside out. Building an LFS system
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| 20 | helps demonstrate what makes Linux tick, and how things work together
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| 21 | and depend on each other. One of the best things that this learning
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| 22 | experience provides is the ability to customize Linux to your own
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| 23 | tastes and needs.</para>
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| 24 |
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| 25 | <para>A key benefit of LFS is that it allows users to have more
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| 26 | control over the system without relying on someone else's Linux
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| 27 | implementation. With LFS, <emphasis>you</emphasis> are in the
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| 28 | driver's seat and dictate every aspect of the system, such as the
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| 29 | directory layout and bootscript setup. You also dictate where, why,
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| 30 | and how programs are installed.</para>
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| 31 |
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| 32 | <para>Another benefit of LFS is the ability to create a very compact
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| 33 | Linux system. When installing a regular distribution, one is often
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| 34 | forced to install several programs which are probably never used. They
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| 35 | waste precious disk space, or worse, CPU cycles. It isn't difficult to
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| 36 | build an LFS system of less than 100 megabytes (MB), which is
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| 37 | substantially smaller compared to most existing setups. Does this
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| 38 | still sound like a lot of space? A few of us have been working on
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| 39 | creating a very small embedded LFS system. We successfully built a
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| 40 | system that was just enough to run the Apache web server with
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| 41 | approximately 8MB of disk space used. Further stripping could bring
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| 42 | that down to 5 MB or less. Try that with a regular distribution!
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| 43 | This is only one of the many benefits of designing your own Linux
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| 44 | implementation.</para>
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[287ea55] | 45 |
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| 46 | <para>We could compare Linux distributions to a hamburger you buy at a
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[ee45b2ee] | 47 | fast-food restaurant -- you have no idea what might be in what you are
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| 48 | eating. LFS, on the other hand, doesn't give you a hamburger, but
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| 49 | rather the recipe to make a hamburger. This allows you to review the
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| 50 | recipe, omit unwanted ingredients, and add your own ingredients to
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| 51 | enhance the flavor of your burger. When you are satisfied with the
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| 52 | recipe, move on to preparing it. It can be made to exact
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| 53 | specifications -- broil it, bake it, deep-fry it or barbecue
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| 54 | it.</para>
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| 55 |
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| 56 | <para>Another analogy that we can use is that of comparing LFS with a
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| 57 | finished house. LFS provides the skeletal plan of a house, but it's up
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| 58 | to you to build it. LFS maintains the freedom to adjust plans
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| 59 | throughout the process, customizing it to the user's needs and
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| 60 | preferences.</para>
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| 61 |
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| 62 | <para>An additional advantage of a custom built Linux system is
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| 63 | security. By compiling the entire system from source code, you are
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| 64 | empowered to audit everything and apply all the security patches
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| 65 | desired. It is no longer necessary to wait for somebody else to
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| 66 | compile binary packages that fix a security hole, and unless you
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| 67 | examine the patch and implement it yourself, you have no guarantee
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| 68 | that the new binary package was built correctly and adequately fixes
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| 69 | the problem.</para>
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| 70 |
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| 71 | <para>The goal of Linux From Scratch is to build a complete and usable
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| 72 | foundation-level system. Readers who do not wish to build their own
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| 73 | Linux system from scratch may not benefit from the information in this
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| 74 | book. If you only want to know what happens while your computer boots,
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| 75 | we recommend the <quote>From Power Up To Bash Prompt</quote> HOWTO
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| 76 | located at <ulink url="http://axiom.anu.edu.au/~okeefe/p2b/"/> or on
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| 77 | The Linux Documentation Project's (TLDP) website at <ulink
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| 78 | url="http://www.tldp.org/HOWTO/From-PowerUp-To-Bash-Prompt.html"/>.
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| 79 | The HOWTO builds a bare system which is similar to that of this book,
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| 80 | but it focuses strictly on creating a system capable of booting to a
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| 81 | BASH prompt. Consider your objective. If you wish to build a Linux
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| 82 | system while learning along the way, then this book is your best
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| 83 | choice.</para>
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| 84 |
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| 85 | <para>There are too many good reasons to build your own LFS system to
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| 86 | list them all here. This section is only the tip of the iceberg. As
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| 87 | you continue in your LFS experience, you will find the power that
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[287ea55] | 88 | information and knowledge truly bring.</para>
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| 89 |
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| 90 | </sect1>
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[ee45b2ee] | 91 |
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