| 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>In this chapter, we enter the building site and start constructing the
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| 14 | LFS system in earnest. That is, we chroot into the temporary mini Linux system,
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| 15 | make a few final preparations, and then begin installing the packages.</para>
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| 16 |
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| 17 | <para>The installation of this software is straightforward. Although in many
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| 18 | cases the installation instructions could be made shorter and more generic,
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| 19 | we have opted to provide the full instructions for every package to minimize
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| 20 | the possibilities for mistakes. The key to learning what makes a Linux system
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| 21 | work is to know what each package is used for and why the user (or the system)
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| 22 | needs it. For every installed package, a summary of its contents is given,
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| 23 | followed by concise descriptions of each program and library the package
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| 24 | installed.</para>
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| 25 |
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| 26 | <para>If using compiler optimizations, please review the optimization hint at
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| 27 | <ulink url="&hints-root;optimization.txt"/>. Compiler optimizations can make
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| 28 | a program run slightly faster, but they may also cause compilation
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| 29 | difficulties and problems when running the program. If a package refuses to
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| 30 | compile when using optimization, try to compile it without optimization and
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| 31 | see if that fixes the problem. Even if the package does compile when using
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| 32 | optimization, there is the risk it may have been compiled incorrectly because
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| 33 | of the complex interactions between the code and build tools. Also note that
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| 34 | the <option>-march</option> and <option>-mtune</option> options using values
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| 35 | not specified in the book have not been tested. This may cause problems with
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| 36 | the toolchain packages (Binutils, GCC and Glibc). The small potential gains
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| 37 | achieved in using compiler optimizations are often outweighed by the risks.
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| 38 | First-time builders of LFS are encouraged to build without custom
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| 39 | optimizations. The subsequent system will still run very fast and be stable
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| 40 | at the same time.</para>
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| 41 |
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| 42 | <para>The order that packages are installed in this chapter needs to be
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| 43 | strictly followed to ensure that no program accidentally acquires a path
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| 44 | referring to <filename class="directory">/tools</filename> hard-wired into
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| 45 | it. For the same reason, do not compile packages in parallel. Compiling in
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| 46 | parallel may save time (especially on dual-CPU machines), but it could result
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| 47 | in a program containing a hard-wired path to <filename
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| 48 | class="directory">/tools</filename>, which will cause the program to stop
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| 49 | working when that directory is removed.</para>
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| 50 |
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| 51 | <para>Before the installation instructions, each installation page provides
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| 52 | information about the package, including a concise description of what it
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| 53 | contains, approximately how long it will take to build, and how much disk
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| 54 | space is required during this building process. Following the installation
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| 55 | instructions, there is a list of programs and libraries (along with brief
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| 56 | descriptions of these) that the package installs.</para>
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| 57 |
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| 58 | </sect1>
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