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="ch-scatter-how">
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7 | <title>How to Build an LFS System</title>
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8 | <?dbhtml filename="how.html"?>
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9 |
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10 | <para>The LFS system will be built by using a previously installed
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11 | Linux distribution (such as Debian, Mandrake, Red Hat, or SuSE). This
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12 | existing Linux system (the host) will be used as a starting point to
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13 | provide necessary programs, including a compiler, linker, and shell,
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14 | to build the new system. Select the <quote>development</quote> option
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15 | during the distribution installation to be able to access these
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16 | tools.</para>
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17 |
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18 | <para>As an alternative to installing an entire separate distribution onto your
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19 | machine, you may wish to use the Linux From Scratch LiveCD. The CD works well as
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20 | a host system, providing all the tools you need to successfully follow the
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21 | instructions in this book. Additionally, it contains all the source packages,
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22 | patches and a copy of this book. So once you have the CD, no network connection
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23 | or additional downloads are necessary. For more information about the LFS LiveCD
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24 | or to download a copy, visit <ulink url="&livecd-root;"/>.</para>
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25 |
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26 | <para><xref linkend="chapter-partitioning"/> of this book describes how
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27 | to create a new Linux native partition and file system, the place
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28 | where the new LFS system will be compiled and installed. <xref
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29 | linkend="chapter-getting-materials"/> explains which packages and
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30 | patches need to be downloaded to build an LFS system and how to store
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31 | them on the new file system. <xref linkend="chapter-final-preps"/>
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32 | discusses the setup for an appropriate working environment. Please read
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33 | <xref linkend="chapter-final-preps"/> carefully as it explains several
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34 | important issues the developer should be aware of before beginning to
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35 | work through <xref linkend="chapter-temporary-tools"/> and
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36 | beyond.</para>
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37 |
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38 | <para><xref linkend="chapter-temporary-tools"/> explains the
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39 | installation of a number of packages that will form the basic
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40 | development suite (or toolchain) which is used to build the actual
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41 | system in <xref linkend="chapter-building-system"/>. Some of these
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42 | packages are needed to resolve circular dependencies—for example,
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43 | to compile a compiler, you need a compiler.</para>
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44 |
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45 | <para><xref linkend="chapter-temporary-tools"/> also shows the user how
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46 | to build a first pass of the toolchain, including Binutils and GCC
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47 | (first pass basically means these two core packages will be
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48 | re-installed a second time). The next step is to build Glibc, the C library.
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49 | Glibc will be compiled by the toolchain programs built in the first pass. Then,
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50 | a second pass of the toolchain will be built. This time, the toolchain will be
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51 | dynamically linked against the newly built Glibc. The remaining
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52 | <xref linkend="chapter-temporary-tools"/> packages are built using this second
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53 | pass toolchain. When this is done, the LFS installation process will no longer
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54 | depend on the host distribution, with the exception of the running kernel.
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55 | </para>
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56 |
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57 | <para>While this may initially seem like a lot of work to isolate the new system
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58 | from the host distribution, a full technical explanation is provided at the
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59 | beginning of <xref linkend="chapter-temporary-tools"/>.</para>
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60 |
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61 | <para>In <xref linkend="chapter-building-system"/>, the full LFS system is
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62 | built. The <command>chroot</command> (change root) program is used to enter a virtual
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63 | environment and start a new shell whose root directory will be set to
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64 | the LFS partition. This is very similar to rebooting and instructing
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65 | the kernel to mount the LFS partition as the root partition. The
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66 | system does not actually reboot, but instead <command>chroot</command>'s because creating a
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67 | bootable system requires additional work which is not necessary just
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68 | yet. The major advantage is that <quote>chrooting</quote> allows the
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69 | builder to continue using the host while LFS is being built. While
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70 | waiting for package compilation to complete, a user can switch to a
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71 | different virtual console (VC) or X desktop and continue using the
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72 | computer as normal.</para>
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73 |
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74 | <para>To finish the installation, the LFS-Bootscripts are set up in <xref
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75 | linkend="chapter-bootscripts"/>, and the kernel and boot loader are set
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76 | up in <xref linkend="chapter-bootable"/>. <xref
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77 | linkend="chapter-finalizing"/> contains information on furthering the
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78 | LFS experience beyond this book. After the steps in this book have
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79 | been implemented, the computer will be ready to reboot into the new
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80 | LFS system.</para>
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81 |
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82 | <para>This is the process in a nutshell. Detailed information on each
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83 | step is discussed in the following chapters and package descriptions.
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84 | Items that may seem complicated will be clarified, and everything will
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85 | fall into place as the reader embarks on the LFS adventure.</para>
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86 |
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87 | </sect1>
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88 |
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