| 1 | <?xml version="1.0" encoding="ISO-8859-1"?>
|
|---|
| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
|
|---|
| 3 | <!ENTITY % general-entities SYSTEM "../general.ent">
|
|---|
| 4 | %general-entities;
|
|---|
| 5 | ]>
|
|---|
| 6 | <sect1 id="ch-scatter-how">
|
|---|
| 7 | <title>How to Build an LFS System</title>
|
|---|
| 8 | <?dbhtml filename="how.html"?>
|
|---|
| 9 |
|
|---|
| 10 | <para>The LFS system will be built by using a previously installed
|
|---|
| 11 | Linux distribution (such as Debian, Mandrake, Red Hat, or SuSE). This
|
|---|
| 12 | existing Linux system (the host) will be used as a starting point to
|
|---|
| 13 | provide necessary programs, including a compiler, linker, and shell,
|
|---|
| 14 | to build the new system. Select the <quote>development</quote> option
|
|---|
| 15 | during the distribution installation to be able to access these
|
|---|
| 16 | tools.</para>
|
|---|
| 17 |
|
|---|
| 18 | <para><xref linkend="chapter-partitioning"/> of this book describes how
|
|---|
| 19 | to create a new Linux native partition and file system, the place
|
|---|
| 20 | where the new LFS system will be compiled and installed. <xref
|
|---|
| 21 | linkend="chapter-getting-materials"/> explains which packages and
|
|---|
| 22 | patches need to be downloaded to build an LFS system and how to store
|
|---|
| 23 | them on the new file system. <xref linkend="chapter-final-preps"/>
|
|---|
| 24 | discusses the setup for an appropriate work environment. Please read
|
|---|
| 25 | <xref linkend="chapter-final-preps"/> carefully as it explains several
|
|---|
| 26 | important issues the developer should be aware of before beginning to
|
|---|
| 27 | work through <xref linkend="chapter-temporary-tools"/> and
|
|---|
| 28 | beyond.</para>
|
|---|
| 29 |
|
|---|
| 30 | <para><xref linkend="chapter-temporary-tools"/> explains the
|
|---|
| 31 | installation of a number of packages that will form the basic
|
|---|
| 32 | development suite (or toolchain) which is used to build the actual
|
|---|
| 33 | system in <xref linkend="chapter-building-system"/>. Some of these
|
|---|
| 34 | packages are needed to resolve circular dependencies—for example,
|
|---|
| 35 | to compile a compiler, you need a compiler.</para>
|
|---|
| 36 |
|
|---|
| 37 | <para><xref linkend="chapter-temporary-tools"/> also shows the user how
|
|---|
| 38 | to build a first pass of the toolchain, including Binutils and GCC
|
|---|
| 39 | (first pass basically means these two core packages will be
|
|---|
| 40 | re-installed a second time). The next step is to build Glibc, the C library.
|
|---|
| 41 | Glibc will be compiled by the toolchain programs built in the first pass. Then,
|
|---|
| 42 | a second pass of the toolchain will be built. This time, the toolchain will be
|
|---|
| 43 | dynamically linked against the newly built Glibc. The remaining
|
|---|
| 44 | <xref linkend="chapter-temporary-tools"/> packages are built using this second
|
|---|
| 45 | pass toolchain. When this is done, the LFS installation process will no longer
|
|---|
| 46 | depend on the host distribution, with the exception of the running kernel.
|
|---|
| 47 | </para>
|
|---|
| 48 |
|
|---|
| 49 | <para>While this may initially seem like a lot of work to get away
|
|---|
| 50 | from a host distribution, a full technical explanation is provided at
|
|---|
| 51 | the beginning of <xref linkend="chapter-temporary-tools"/>.</para>
|
|---|
| 52 |
|
|---|
| 53 | <para>In <xref linkend="chapter-building-system"/>, the full LFS system is
|
|---|
| 54 | built. The chroot (change root) program is used to enter a virtual
|
|---|
| 55 | environment and start a new shell whose root directory will be set to
|
|---|
| 56 | the LFS partition. This is very similar to rebooting and instructing
|
|---|
| 57 | the kernel to mount the LFS partition as the root partition. The
|
|---|
| 58 | system does not actually reboot, but instead chroots because creating a
|
|---|
| 59 | bootable system requires additional work which is not necessary just
|
|---|
| 60 | yet. The major advantage is that <quote>chrooting</quote> allows the
|
|---|
| 61 | builder to continue using the host while LFS is being built. While
|
|---|
| 62 | waiting for package compilation to complete, a user can switch to a
|
|---|
| 63 | different virtual console (VC) or X desktop and continue using the
|
|---|
| 64 | computer as normal.</para>
|
|---|
| 65 |
|
|---|
| 66 | <para>To finish the installation, the bootscripts are set up in <xref
|
|---|
| 67 | linkend="chapter-bootscripts"/>, and the kernel and boot loader are set
|
|---|
| 68 | up in <xref linkend="chapter-bootable"/>. <xref
|
|---|
| 69 | linkend="chapter-finalizing"/> contains information on furthering the
|
|---|
| 70 | LFS experience beyond this book. After the steps in this book have
|
|---|
| 71 | been implemented, the computer will be ready to reboot into the new
|
|---|
| 72 | LFS system.</para>
|
|---|
| 73 |
|
|---|
| 74 | <para>This is the process in a nutshell. Detailed information on each
|
|---|
| 75 | step is discussed in the following chapters and package descriptions.
|
|---|
| 76 | Items that may seem complicated will be clarified, and everything will
|
|---|
| 77 | fall into place as the developer embarks on the LFS adventure.</para>
|
|---|
| 78 |
|
|---|
| 79 | </sect1>
|
|---|
| 80 |
|
|---|
