introduction.xml 1.5 KB

123456789101112131415161718192021222324252627282930313233
  1. <?xml version="1.0" encoding="ISO-8859-1"?>
  2. <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  3. "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  4. <!ENTITY % general-entities SYSTEM "../general.ent">
  5. %general-entities;
  6. ]>
  7. <sect1 id="ch-tools-introduction-chroot">
  8. <?dbhtml filename="introduction.html"?>
  9. <title>Introduction</title>
  10. <para>This chapter shows how to build the last missing bits of the temporary
  11. system: first, the tools needed by the build machinery of various packages,
  12. then three packages needed to run tests. Now that all circular dependencies
  13. have been resolved, we can use a <quote>chroot</quote> environment,
  14. completely isolated the host operating system used for the build, except
  15. for the running kernel.</para>
  16. <para>For proper operation of the isolated environment, some communication
  17. with the running kernel must be established. This is done through the
  18. so-called <emphasis>Virtual Kernel File Systems</emphasis>, which must be
  19. mounted when entering the chroot environment. You may want to check
  20. that they are mounted by issuing <command>findmnt</command>.</para>
  21. <para>Until <xref linkend="ch-tools-chroot"/>, the commands must be
  22. run as <systemitem class="username">root</systemitem>, with the
  23. <envar>LFS</envar> variable set. After entering chroot, all commands
  24. are run as root, fortunately without access to the OS of the computer
  25. you built LFS on. Be careful anyway, as it is easy to destroy the whole
  26. LFS system with badly formed commands.</para>
  27. </sect1>