1 | <?xml version="1.0" encoding="ISO-8859-1"?>
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2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" "http://www.oasis-open.org/docbook/xml/4.4/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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10 | <para>There are many reasons why somebody would want to read this
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11 | book. The principle reason is 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 include several programs which are probably never used.
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35 | These programs waste precious disk space, or worse, CPU cycles. It is
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36 | not difficult to build an LFS system of less than 100 megabytes (MB),
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37 | which is substantially smaller when compared to the majority of existing installations. Does
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38 | this 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 specialized 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 | this 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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45 |
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46 | <para>We could compare Linux distributions to a hamburger purchased at
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47 | a fast-food restaurant—you have no idea what might be in what
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48 | you are eating. LFS, on the other hand, does not give you a hamburger.
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49 | Rather, LFS provides the recipe to make the exact hamburger desired.
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50 | This allows users to review the recipe, omit unwanted ingredients, and
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51 | add your own ingredients to enhance the flavor of the burger.
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52 | When you are satisfied with the recipe, move on to preparing it. It
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53 | can be made to exact specifications—broil it, bake it, deep-fry
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54 | it, or barbecue 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 is 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. 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 the 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-HOWTO.html"/>.
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79 | The HOWTO builds a 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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88 | information and knowledge truly bring.</para>
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89 |
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90 | </sect1>
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91 |
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