| 1 | <?xml version="1.0" encoding="ISO-8859-1"?>
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| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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| 3 | "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
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| 4 | <!ENTITY % general-entities SYSTEM "../../general.ent">
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| 5 | %general-entities;
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| 6 | ]>
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| 7 |
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| 8 | <sect1 id="ch-system-introduction">
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| 9 | <?dbhtml filename="introduction.html"?>
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| 10 |
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| 11 | <title>Introduction</title>
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| 12 |
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| 13 | <para os="a">In this chapter, we enter the building site and start
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| 14 | constructing the CLFS system in earnest. The installation of this
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| 15 | software is straightforward. Although in many cases the installation
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| 16 | instructions could be made shorter and more generic, we have opted
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| 17 | to provide the full instructions for every package to minimize the
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| 18 | possibilities for mistakes. The key to learning what makes a Linux
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| 19 | system work is to know what each package is used for and why the user
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| 20 | (or the system) needs it. For every installed package, a summary of
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| 21 | its contents is given, followed by concise descriptions of each
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| 22 | program and library the package installed.</para>
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| 23 |
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| 24 | <para os="b">If using compiler optimizations, please review the
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| 25 | optimization hint at <ulink url="&hints-root;optimization.txt"/>.
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| 26 | Compiler optimizations can make a program run slightly faster, but
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| 27 | they may also cause compilation difficulties and problems when
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| 28 | running the program. If a package refuses to compile when using
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| 29 | optimization, try to compile it without optimization and see if
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| 30 | that fixes the problem. Even if the package
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| 31 | does compile when using optimization, there is the risk it may have
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| 32 | been compiled incorrectly because of the complex interactions between
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| 33 | the code and build tools. Also note that the <option>-march</option>
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| 34 | and <option>-mtune</option> options may cause problems with the toolchain
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| 35 | packages (Binutils, GCC and Glibc). The small potential gains achieved in
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| 36 | using compiler optimizations are often outweighed by the risks. First-time
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| 37 | builders of CLFS are encouraged to build without custom optimizations.
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| 38 | The subsequent system will still run very fast and be stable at the
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| 39 | same time.</para>
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| 40 |
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| 41 | <para os="c">The order that packages are installed in this chapter needs to
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| 42 | be strictly followed to ensure that no program accidentally acquires a
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| 43 | path referring to <filename class="directory">/tools</filename>
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| 44 | hard-wired into it. For the same reason, do not compile packages in
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| 45 | parallel. Compiling in parallel may save time (especially on dual-CPU
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| 46 | machines), but it could result in a program containing a hard-wired
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| 47 | path to <filename class="directory">/tools</filename>, which will
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| 48 | cause the program to stop working when that directory is
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| 49 | removed.</para>
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| 50 |
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| 51 | <para os="d">To keep track of which package installs particular files, a
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| 52 | package manager can be used. For a general overview of different styles of
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| 53 | package managers, please take a look at the next page.</para>
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| 54 |
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| 55 | </sect1>
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