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 |
|
---|
8 | <sect1 id="ch-tools-adjusting">
|
---|
9 | <?dbhtml filename="adjusting.html"?>
|
---|
10 |
|
---|
11 | <title>Adjusting the Toolchain</title>
|
---|
12 |
|
---|
13 | <para>Now that the temporary C libraries have been installed, all
|
---|
14 | tools compiled in the rest of this chapter should be linked against
|
---|
15 | these libraries. In order to accomplish this, the cross-compiler's
|
---|
16 | specs file needs to be adjusted to point to the new dynamic linker
|
---|
17 | in <filename class="directory">/tools</filename>.</para>
|
---|
18 |
|
---|
19 | <para>This is done by dumping the compiler's <quote>specs</quote> file to a
|
---|
20 | location where it will look for it by default.
|
---|
21 | A simple <command>sed</command> substitution then alters the
|
---|
22 | dynamic linker that GCC will use. The principle here is to find all references
|
---|
23 | to the dynamic linker file in <filename class="directory">/lib</filename>
|
---|
24 | or possibly <filename class="directory">/lib64</filename> if the host system
|
---|
25 | is 64-bit capable, and adjust them to point to the new location in
|
---|
26 | <filename class="directory">/tools</filename>.</para>
|
---|
27 |
|
---|
28 | <para>For the sake of accuracy, it is recommended to use a copy-and-paste
|
---|
29 | method when issuing the following command. Be sure to visually inspect the
|
---|
30 | specs file to verify that it has properly adjusted all references to the
|
---|
31 | dynamic linker location. Refer to <xref
|
---|
32 | linkend="ch-tools-toolchaintechnotes" role=","/> for the default name
|
---|
33 | of the dynamic linker, if necessary.</para>
|
---|
34 |
|
---|
35 | <!-- Ampersands are needed to allow copy and paste -->
|
---|
36 | <screen><userinput>SPECS=`dirname $($LFS_TGT-gcc -print-libgcc-file-name)`/specs
|
---|
37 | $LFS_TGT-gcc -dumpspecs | sed \
|
---|
38 | -e 's@/lib\(64\)\?/ld@/tools&@g' \
|
---|
39 | -e "/^\*cpp:$/{n;s,$, -isystem /tools/include,}" > $SPECS
|
---|
40 | echo "New specs file is: $SPECS"
|
---|
41 | unset SPECS</userinput></screen>
|
---|
42 |
|
---|
43 | <caution>
|
---|
44 | <para>At this point, it is imperative to stop and ensure that the basic
|
---|
45 | functions (compiling and linking) of the new toolchain are working as
|
---|
46 | expected. To perform a sanity check, run the following commands:</para>
|
---|
47 |
|
---|
48 | <screen><userinput>echo 'main(){}' > dummy.c
|
---|
49 | $LFS_TGT-gcc -B/tools/lib dummy.c
|
---|
50 | readelf -l a.out | grep ': /tools'</userinput></screen>
|
---|
51 |
|
---|
52 | <para>If everything is working correctly, there should be no errors,
|
---|
53 | and the output of the last command will be of the form:</para>
|
---|
54 |
|
---|
55 | <screen><computeroutput>[Requesting program interpreter: /tools/lib/ld-linux.so.2]</computeroutput></screen>
|
---|
56 |
|
---|
57 | <para>Note that <filename class="directory">/tools/lib</filename>, or
|
---|
58 | <filename class="directory">/tools/lib64</filename> for 64-bit machines
|
---|
59 | appears as the prefix of the dynamic linker.</para>
|
---|
60 |
|
---|
61 | <para>If the output is not shown as above or there was no output at all,
|
---|
62 | then something is wrong. Investigate and retrace the steps to find out
|
---|
63 | where the problem is and correct it. This issue must be resolved before
|
---|
64 | continuing on. Something may have gone wrong with the
|
---|
65 | specs file amendment above. In this case, redo the specs file amendment,
|
---|
66 | being careful to copy-and-paste the commands.</para>
|
---|
67 |
|
---|
68 | <para>Once all is well, clean up the test files:</para>
|
---|
69 |
|
---|
70 | <screen><userinput>rm -v dummy.c a.out</userinput></screen>
|
---|
71 |
|
---|
72 | </caution>
|
---|
73 |
|
---|
74 | <note><para>Building Binutils in the next section will serve as an additional check that
|
---|
75 | the toolchain has been built properly. If Binutils fails to build, it is an
|
---|
76 | indication that something has gone wrong with the previous Binutils, GCC, or Glibc
|
---|
77 | installations.</para></note>
|
---|
78 |
|
---|
79 | </sect1>
|
---|