| 1 | <?xml version="1.0" encoding="ISO-8859-1"?>
|
|---|
| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
|
|---|
| 3 | "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
|
|---|
| 4 | <!ENTITY % general-entities SYSTEM "../../general.ent">
|
|---|
| 5 | %general-entities;
|
|---|
| 6 | ]>
|
|---|
| 7 |
|
|---|
| 8 | <sect1 id="ch-chroot-chroot">
|
|---|
| 9 | <?dbhtml filename="chroot.html"?>
|
|---|
| 10 |
|
|---|
| 11 | <title>Entering the Chroot Environment</title>
|
|---|
| 12 |
|
|---|
| 13 | <para>It is time to enter the chroot environment to begin building
|
|---|
| 14 | and installing the final CLFS system. As user <systemitem
|
|---|
| 15 | class="username">root</systemitem>, run the following command to
|
|---|
| 16 | enter the realm that is, at the moment, populated with only the
|
|---|
| 17 | temporary tools:</para>
|
|---|
| 18 |
|
|---|
| 19 | <screen><userinput>chroot "${CLFS}" /tools/bin/env -i \
|
|---|
| 20 | HOME=/root TERM="${TERM}" PS1='\u:\w\$ ' \
|
|---|
| 21 | PATH=/bin:/usr/bin:/sbin:/usr/sbin:/tools/bin \
|
|---|
| 22 | /tools/bin/bash --login +h</userinput></screen>
|
|---|
| 23 |
|
|---|
| 24 | <para>The <parameter>-i</parameter> option given to the
|
|---|
| 25 | <command>env</command> command will clear all variables of the chroot
|
|---|
| 26 | environment. After that, only the <envar>HOME</envar>,
|
|---|
| 27 | <envar>TERM</envar>, <envar>PS1</envar>, and
|
|---|
| 28 | <envar>PATH</envar> variables are set again. The
|
|---|
| 29 | <parameter>TERM=${TERM}</parameter> construct will set the
|
|---|
| 30 | <envar>TERM</envar> variable inside chroot to the same value as
|
|---|
| 31 | outside chroot. This variable is needed for programs like
|
|---|
| 32 | <command>vim</command> and <command>less</command> to operate
|
|---|
| 33 | properly. If other variables are needed, such as
|
|---|
| 34 | <envar>CFLAGS</envar> or <envar>CXXFLAGS</envar>, this is
|
|---|
| 35 | a good place to set them again.</para>
|
|---|
| 36 |
|
|---|
| 37 | <para>From this point on, there is no need to use the
|
|---|
| 38 | <envar>CLFS</envar> variable anymore, because all work will be
|
|---|
| 39 | restricted to the CLFS file system. This is because the Bash shell is
|
|---|
| 40 | told that <filename class="directory">${CLFS}</filename> is now the root
|
|---|
| 41 | (<filename class="directory">/</filename>) directory.</para>
|
|---|
| 42 |
|
|---|
| 43 | <para>Notice that <filename class="directory">/tools/bin</filename> comes
|
|---|
| 44 | last in the <envar>PATH</envar>. This means that a temporary tool will no
|
|---|
| 45 | longer be used once its final version is installed. This occurs when the
|
|---|
| 46 | shell does not <quote>remember</quote> the locations of executed
|
|---|
| 47 | binaries—for this reason, hashing is switched off by passing the
|
|---|
| 48 | <parameter>+h</parameter> option to <command>bash</command>.</para>
|
|---|
| 49 |
|
|---|
| 50 | <para>It is important that all the commands throughout the remainder
|
|---|
| 51 | of this chapter and the following chapters are run from within the
|
|---|
| 52 | chroot environment. If you leave this environment for any reason
|
|---|
| 53 | (rebooting for example), remember to first mount the <systemitem
|
|---|
| 54 | class="filesystem">proc</systemitem> and <systemitem
|
|---|
| 55 | class="filesystem">devpts</systemitem> file systems (discussed in the
|
|---|
| 56 | previous section) and enter chroot again before continuing with the
|
|---|
| 57 | installations.</para>
|
|---|
| 58 |
|
|---|
| 59 | <para>Note that the <command>bash</command> prompt will say
|
|---|
| 60 | <computeroutput>I have no name!</computeroutput> This is normal because the
|
|---|
| 61 | <filename>/etc/passwd</filename> file has not been created yet.</para>
|
|---|
| 62 |
|
|---|
| 63 | </sect1>
|
|---|
