mirror of
https://git.linuxfromscratch.org/lfs.git
synced 2026-05-20 05:10:27 -04:00
ef1365774d
git-svn-id: http://svn.linuxfromscratch.org/LFS/branches/testing/BOOK@4000 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689
107 lines
4.8 KiB
XML
107 lines
4.8 KiB
XML
<?xml version="1.0" encoding="ISO-8859-1"?>
|
|
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
|
|
<!ENTITY % general-entities SYSTEM "../general.ent">
|
|
%general-entities;
|
|
]>
|
|
<sect1 id="ch-system-readjusting">
|
|
<title>Re-adjusting the toolchain</title>
|
|
<?dbhtml filename="readjusting.html"?>
|
|
|
|
<para>Now that the new and final C libraries have been installed, it
|
|
is time to adjust the toolchain again. The toolchain will be adjusted
|
|
so that it will link any newly compiled program against these new
|
|
libraries. This is the same process used in the
|
|
<quote>Adjusting</quote> phase in the beginning of <xref
|
|
linkend="chapter-temporary-tools"/>, even though it looks to be
|
|
reversed -- in that chapter, the chain was guided from the host's
|
|
<filename class="directory">/{,usr/}lib</filename> directories to the
|
|
new <filename class="directory">/tools/lib</filename> directory. Now,
|
|
the chain will be guided from that same <filename
|
|
class="directory">/tools/lib</filename> directory to the LFS's
|
|
<filename class="directory">/{,usr/}lib</filename> directories.</para>
|
|
|
|
<para>Start by adjusting the linker. The source and build directories
|
|
from the second pass over Binutils were retained for this purpose.
|
|
Install the adjusted linker by running the following command from
|
|
within the <filename class="directory">binutils-build</filename>
|
|
directory:</para>
|
|
|
|
<screen><userinput>make -C ld INSTALL=/tools/bin/install install</userinput></screen>
|
|
|
|
<note><para>If the earlier warning to retain the Binutils source and
|
|
build directories from the second pass in <xref
|
|
linkend="chapter-temporary-tools"/> was missed, or if they were
|
|
accidentally deleted or are inaccessible, ignore the above command.
|
|
The result will be that the next package, Binutils, will link against
|
|
the C libraries in <filename class="directory">/tools</filename>
|
|
rather than in <filename class="directory">/{,usr/}lib</filename>.
|
|
This is not ideal, however, testing has shown that the resulting
|
|
Binutils program binaries should be identical.</para></note>
|
|
|
|
<para>From now on, every compiled program will link only against the
|
|
libraries in <filename class="directory">/usr/lib</filename> and
|
|
<filename class="directory">/lib</filename>. The extra
|
|
<parameter>INSTALL=/tools/bin/install</parameter> option is needed
|
|
because the <filename>Makefile</filename> file created during the
|
|
second pass still contains the reference to
|
|
<command>/usr/bin/install</command>, which has not been installed yet.
|
|
Some host distributions contain a <filename
|
|
class="symlink">ginstall</filename> symbolic link which takes
|
|
precedence in the <filename>Makefile</filename> file and can cause a
|
|
problem here. The above command takes care of this issue.</para>
|
|
|
|
<para>Remove the Binutils source and build directories now.</para>
|
|
|
|
<para>Next, amend the GCC specs file so that it points to the new
|
|
dynamic linker. A sed to accomplish this just like before:</para>
|
|
|
|
<!-- Ampersands are needed to allow cut and paste -->
|
|
|
|
<screen><userinput>sed -i 's@ /tools/lib/ld-linux.so.2@ /lib/ld-linux.so.2@g' \
|
|
`gcc --print-file specs`</userinput></screen>
|
|
|
|
<para>Cutting and pasting the above is recommended. It is a good idea
|
|
to visually inspect the specs file to verify the intended change was
|
|
actually made.</para>
|
|
|
|
<important><para>If working on a platform where the name of the
|
|
dynamic linker is something other than
|
|
<filename>ld-linux.so.2</filename>, substitute
|
|
<filename>ld-linux.so.2</filename> with the name of the platform's
|
|
dynamic linker in the above commands. Refer back to <xref
|
|
linkend="ch-tools-toolchaintechnotes"/> if
|
|
necessary.</para></important>
|
|
|
|
<caution><para>It is imperative at this point to stop and ensure that
|
|
the basic functions (compiling and linking) of the adjusted toolchain
|
|
are working as expected. To do this, perform a simple sanity
|
|
check:</para>
|
|
|
|
<screen><userinput>echo 'main(){}' > dummy.c
|
|
cc dummy.c
|
|
readelf -l a.out | grep ': /lib'</userinput></screen>
|
|
|
|
<para>If everything is working correctly, there should be no errors,
|
|
and the output of the last command will be (allowing for platform
|
|
specific differences in dynamic linker name):</para>
|
|
|
|
<screen><computeroutput>[Requesting program interpreter: /lib/ld-linux.so.2]</computeroutput></screen>
|
|
|
|
<para>Note especially that <filename class="directory">/lib</filename> is now
|
|
the prefix of our dynamic linker.</para>
|
|
|
|
<para>If the output does not appear as shown above or is not received
|
|
at all, then something is seriously wrong. Investigate and retrace the
|
|
steps to find out where the problem is and correct it. The most likely
|
|
reason is that something went wrong with the specs file amendment
|
|
above. Any issues will need to be resolved before continuing on with
|
|
the process.</para>
|
|
|
|
<para>Once everything is working correctly, clean up the test
|
|
files:</para>
|
|
|
|
<screen><userinput>rm dummy.c a.out</userinput></screen></caution>
|
|
|
|
</sect1>
|
|
|