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Diffstat (limited to 'chapter05/adjusting.xml')
| -rw-r--r-- | chapter05/adjusting.xml | 85 |
1 files changed, 77 insertions, 8 deletions
diff --git a/chapter05/adjusting.xml b/chapter05/adjusting.xml index ac342fe87..834ef166f 100644 --- a/chapter05/adjusting.xml +++ b/chapter05/adjusting.xml @@ -7,12 +7,34 @@ <title>Adjusting the Toolchain</title> <?dbhtml filename="adjusting.html"?> -<para>Run the following command from within -the <filename class="directory">binutils-build</filename> directory:</para> +<para>Now that the temporary C libraries have been installed, all +tools compiled in the rest of this chapter should be linked against +these libraries. In order to accomplish this, the linker and the +compiler's specs file need to be adjusted.</para> + +<para>The linker, adjusted at the end of the first pass of Binutils, +is installed by running the following command from within the +<filename class="directory">binutils-build</filename> directory:</para> <screen><userinput>make -C ld install</userinput></screen> -<para>Amend the GCC specs file:</para> +<para>From this point onwards, everything will link only +against the libraries in <filename class="directory">/tools/lib</filename>.</para> + +<note><para>If the earlier warning to retain the Binutils source and +build directories from the first pass was missed, ignore the above +command. This results in a small chance that the subsequent testing +programs will link against libraries on the host. This is not ideal, +but it is not a major problem. The situation is corrected when the +second pass of Binutils is installed later.</para></note> + +<para>Now that the adjusted linker is installed, the Binutils build and source +directories should be removed.</para> + +<para>The next task is to amend the GCC specs file so that it points +to the new dynamic linker. A simple sed script will accomplish this:</para> + +<!-- Ampersands are needed to allow copy and paste --> <screen><userinput>SPECFILE=`gcc --print-file specs` && sed 's@ /lib/ld-linux.so.2@ /tools/lib/ld-linux.so.2@g' \ @@ -20,24 +42,71 @@ sed 's@ /lib/ld-linux.so.2@ /tools/lib/ld-linux.so.2@g' \ mv -f tempspecfile $SPECFILE && unset SPECFILE</userinput></screen> -<para>Make clean-up:</para> +<para><phrase condition="html">It is recommended that the above +command be copy-and-pasted in order to ensure accuracy.</phrase> +Alternatively, the specs file can be edited by hand. This is done by +replacing every occurrence of <quote>/lib/ld-linux.so.2</quote> with +<quote>/tools/lib/ld-linux.so.2</quote></para> + +<para>Be sure to visually inspect the specs file in order to verify the +intended changes have been made.</para> + +<important><para>If working on a platform where the name of the +dynamic linker is something other than +<filename class="libraryfile">ld-linux.so.2</filename>, replace +<quote>ld-linux.so.2</quote> with the name of the platform's +dynamic linker in the above commands. Refer back to <xref +linkend="ch-tools-toolchaintechnotes" role=","/> if +necessary.</para></important> + +<para>There is a possibility that some include files from the host +system have found their way into GCC's private include dir. This can +happen as a result of GCC's <quote>fixincludes</quote> process, which runs as part +of the GCC build. This is explained in more detail later in this +chapter. Run the following command to eliminate this +possibility:</para> <screen><userinput>rm -f /tools/lib/gcc/*/*/include/{pthread.h,bits/sigthread.h}</userinput></screen> -<para>Test the tools:</para> +<caution><para>At this point, it is imperative to stop and ensure that +the basic functions (compiling and linking) of the new toolchain are +working as expected. To perform a sanity check, run the following +commands:</para> <screen><userinput>echo 'main(){}' > dummy.c cc dummy.c readelf -l a.out | grep ': /tools'</userinput></screen> -<para>The output of the last command will be of the form:</para> +<para>If everything is working correctly, there should be no errors, +and the output of the last command will be of the form:</para> <screen><computeroutput>[Requesting program interpreter: /tools/lib/ld-linux.so.2]</computeroutput></screen> -<para>Remove the test files:</para> +<para>Note that <filename class="directory">/tools/lib</filename> +appears as the prefix of the dynamic linker.</para> -<screen><userinput>rm dummy.c a.out</userinput></screen> +<para>If the output is not shown as above or there was no output at +all, then something is wrong. Investigate and retrace the steps to +find out where the problem is and correct it. This issue must be +resolved before continuing on. First, perform the sanity check again, +using <command>gcc</command> instead of <command>cc</command>. If this +works, then the <filename class="symlink">/tools/bin/cc</filename> symlink is missing. +Revisit <xref linkend="ch-tools-gcc-pass1" role=","/> and install the symlink. +Next, ensure that the <envar>PATH</envar> is correct. This can be checked by running +<command>echo $PATH</command> and verifying that <filename +class="directory">/tools/bin</filename> is at the head of the list. If +the <envar>PATH</envar> is wrong it could mean that you are not logged in as user +<emphasis>lfs</emphasis> or that something went wrong back in <xref +linkend="ch-tools-settingenviron" role="."/> Another option is that something +may have gone wrong with the specs file amendment above. In this case, +redo the specs file amendment<phrase condition="html">, being careful to copy-and-paste the +commands</phrase>.</para> +<para>Once all is well, clean up the test files:</para> + +<screen><userinput>rm dummy.c a.out</userinput></screen> +</caution> </sect1> + |