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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-intro-how"> |
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9 | <?dbhtml filename="how.html"?> |
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10 | |
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11 | <title>How to Build an LFS System</title> |
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12 | |
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13 | <para>The LFS system will be built by using a previously installed |
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14 | Linux distribution (such as Debian, Mandrake, Red Hat, or SuSE). This |
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15 | existing Linux system (the host) will be used as a starting point to |
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16 | provide necessary programs, including a compiler, linker, and shell, |
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17 | to build the new system. Select the <quote>development</quote> option |
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18 | during the distribution installation to be able to access these |
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19 | tools.</para> |
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20 | |
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21 | <para>As an alternative to installing an entire separate distribution |
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22 | onto your machine, and if your host machine is x86 based, you may wish to |
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23 | use the Linux From Scratch LiveCD. The CD works well as a host system, |
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24 | providing all the tools you need to successfully follow the instructions |
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25 | in this book. Additionally, it contains all the source packages, patches |
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26 | and a copy of this book. So once you have the CD, no network connection |
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27 | or additional downloads are necessary. For more information about the |
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28 | LFS LiveCD or to download a copy, visit <ulink url="&livecd-root;"/></para> |
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29 | |
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30 | <!-- --> |
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31 | <para>THE TEXT BELOW NEEDS TO BE REWRITTEN</para> |
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32 | |
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33 | <para><xref linkend="chapter-partitioning"/> of this book describes how |
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34 | to create a new Linux native partition and file system, the place |
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35 | where the new LFS system will be compiled and installed. <xref |
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36 | linkend="chapter-getting-materials"/> explains which packages and |
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37 | patches need to be downloaded to build an LFS system and how to store |
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38 | them on the new file system. <xref linkend="chapter-final-preps"/> |
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39 | discusses the setup for an appropriate working environment. Please read |
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40 | <xref linkend="chapter-final-preps"/> carefully as it explains several |
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41 | important issues the developer should be aware of before beginning to |
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42 | work through <xref linkend="chapter-cross-tools"/> and |
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43 | beyond.</para> |
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44 | |
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45 | <para><xref linkend="chapter-temp-system"/> explains the |
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46 | installation of a number of packages that will form the basic |
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47 | development suite (or toolchain) which is used to build the actual |
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48 | system in <xref linkend="chapter-building-system"/>. Some of these |
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49 | packages are needed to resolve circular dependencies—for example, |
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50 | to compile a compiler, you need a compiler.</para> |
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51 | |
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52 | <para><xref linkend="chapter-temp-system"/> also shows the user |
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53 | how to build a first pass of the toolchain, including Binutils and GCC |
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54 | (first pass basically means these two core packages will be re-installed |
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55 | a second time). The next step is to build Glibc, the C library. Glibc |
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56 | will be compiled by the toolchain programs built in the first pass. Then, |
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57 | a second pass of the toolchain will be built. This time, the toolchain |
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58 | will be dynamically linked against the newly built Glibc. The remaining |
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59 | <xref linkend="chapter-temp-system"/> packages are built using this |
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60 | second pass toolchain. When this is done, the LFS installation process |
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61 | will no longer depend on the host distribution, with the exception of the |
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62 | running kernel. </para> |
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63 | |
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64 | <para>This effort to isolate the new system from the host distribution |
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65 | may seem excessive, but a full technical explanation is provided at the |
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66 | beginning of <xref linkend="chapter-temp-system"/>.</para> |
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67 | |
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68 | <para>In <xref linkend="chapter-building-system"/>, the full LFS system is |
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69 | built. The <command>chroot</command> (change root) program is used to enter |
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70 | a virtual environment and start a new shell whose root directory will be set |
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71 | to the LFS partition. This is very similar to rebooting and instructing the |
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72 | kernel to mount the LFS partition as the root partition. The system does not |
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73 | actually reboot, but instead <command>chroot</command>'s because creating a |
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74 | bootable system requires additional work which is not necessary just yet. |
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75 | The major advantage is that <quote>chrooting</quote> allows the builder to |
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76 | continue using the host while LFS is being built. While waiting for package |
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77 | compilation to complete, a user can switch to a different virtual console |
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78 | (VC) or X desktop and continue using the computer as normal.</para> |
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79 | |
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80 | <para>To finish the installation, the LFS-Bootscripts are set up in <xref |
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81 | linkend="chapter-bootscripts"/>, and the kernel and boot loader are set |
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82 | up in <xref linkend="chapter-bootable"/>. <xref |
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83 | linkend="chapter-finalizing"/> contains information on furthering the |
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84 | LFS experience beyond this book. After the steps in this book have |
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85 | been implemented, the computer will be ready to reboot into the new |
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86 | LFS system.</para> |
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87 | <!-- --> |
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88 | |
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89 | <para>This is the process in a nutshell. Detailed information on each |
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90 | step is discussed in the following chapters and package descriptions. |
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91 | Items that may seem complicated will be clarified, and everything will |
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92 | fall into place as the reader embarks on the LFS adventure.</para> |
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93 | |
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94 | </sect1> |
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