diff options
| -rw-r--r-- | chapter01/changelog.xml | 28 | ||||
| -rw-r--r-- | chapter05/chapter05.xml | 14 | ||||
| -rw-r--r-- | chapter06/chapter06.xml | 92 | ||||
| -rw-r--r-- | chapter08/kernel.xml | 5 | ||||
| -rw-r--r-- | chapter09/theend.xml | 44 |
5 files changed, 122 insertions, 61 deletions
diff --git a/chapter01/changelog.xml b/chapter01/changelog.xml index b0d5635b0..48022c2f7 100644 --- a/chapter01/changelog.xml +++ b/chapter01/changelog.xml @@ -2,10 +2,26 @@ <title>Changelog</title> <?dbhtml filename="changelog.html" dir="chapter01"?> -<para>&version; - &releasedate;</para> +<para>This is version &version; of the Linux From Scratch book, dated +&releasedate;. If this book is more than two months old, a newer and better +version is probably already available. To find out, please check one of the +mirrors via <ulink url="&lfs-root;"/>.</para> + +<para>Below is a list of changes made since the previous release of the book, +first a summary, then a detailed log.</para> <itemizedlist> +<listitem><para>Upgraded to:</para> +<itemizedlist> +<listitem><para>less-382</para></listitem> +<listitem><para>man-pages-1.66</para></listitem> +<listitem><para>ncurses-5.4</para></listitem> +</itemizedlist></listitem> + +<listitem><para>February 22nd, 2004 [alex]: Moved the stripping of the final +system from chapter 9 to the end of chapter 6.</para></listitem> + <listitem><para>February 22nd, 2004 [alex]: Chapter 6 - Coreutils and E2fsprogs: Clarified the prerequisites for running the tests.</para></listitem> @@ -13,11 +29,11 @@ E2fsprogs: Clarified the prerequisites for running the tests.</para></listitem> an unnecessary "{,share/}" from the documentation's <command>rm</command> command.</para></listitem> -<listitem><para>February 14th, 2004 [jeremy]: Chapter 6 - Upgraded Less -to 382.</para></listitem> +<listitem><para>February 14th, 2004 [jeremy]: Chapter 6 - Upgraded to +Less-382.</para></listitem> -<listitem><para>February 14th, 2004 [jeremy]: Chapters 5 & 6 - Upgraded -ncurses to version 5.4, and removed references to etip patch.</para></listitem> +<listitem><para>February 14th, 2004 [jeremy]: Chapters 5 + 6 - Upgraded to +Ncurses-5.4, and removed references to the etip patch.</para></listitem> <listitem><para>February 12th, 2004 [jeremy]: Chapter 6 - Removed explicit paths from the pwconv and grpconv commands, since /usr/sbin is part of @@ -27,7 +43,7 @@ the default path.</para></listitem> installation section to chapter 7.</para></listitem> <listitem><para>February 8th, 2004 [matt]: Chapter 6 - Updated to -man-pages-1.66.</para></listitem> +Man-pages-1.66.</para></listitem> <listitem><para>February 7th, 2004 [alex]: Chapter 1 - Moved the Conventions and Acknowledgements sections to the Preface.</para></listitem> diff --git a/chapter05/chapter05.xml b/chapter05/chapter05.xml index a700a9cc9..0e89c5944 100644 --- a/chapter05/chapter05.xml +++ b/chapter05/chapter05.xml @@ -573,15 +573,15 @@ ensuring to cut-and-paste the commands as was recommended.</para> <title>Stripping</title> <?dbhtml filename="stripping.html" dir="chapter05"?> -<para>The steps in this section are optional. If your LFS partition is rather -small, you will be glad to learn that you can throw away some unnecessary -things. The executables and libraries you have built so far contain about 130 MB -of unneeded debugging symbols. Remove those symbols like this:</para> +<para>The steps in this section are optional, but if your LFS partition is +rather small, you will be glad to learn that you can remove some unnecessary +things. The executables and libraries you have built so far contain about 130 +MB of unneeded debugging symbols. Remove those symbols with:</para> -<screen><userinput>strip --strip-unneeded /tools/{,s}bin/* -strip --strip-debug /tools/lib/*</userinput></screen> +<screen><userinput>strip --strip-debug /tools/lib/* +strip --strip-unneeded /tools/{,s}bin/*</userinput></screen> -<para>The first of the above commands will skip some twenty files, reporting +<para>The last of the above commands will skip some twenty files, reporting that it doesn't recognize their file format. Most of them are scripts instead of binaries.</para> diff --git a/chapter06/chapter06.xml b/chapter06/chapter06.xml index c64770b2a..287b94540 100644 --- a/chapter06/chapter06.xml +++ b/chapter06/chapter06.xml @@ -502,11 +502,98 @@ Most likely something went wrong with the specs file amendment above.</para> &c6-gcc-2953; +<sect1 id="ch-system-aboutdebug"> +<title>About debugging symbols</title> +<?dbhtml filename="aboutdebug.html" dir="chapter06"?> + +<para>Most programs and libraries are, by default, compiled with debugging +symbols included (with <command>gcc</command>'s <emphasis>-g</emphasis> +option). This means that, when debugging a program or library that was compiled +with debugging information included, the debugger can give you not only memory +addresses but also the names of the routines and variables.</para> + +<para>The inclusion of these debugging symbols, however, enlarges a program or +library significantly. To get an idea of the amount of space these symbols +occupy, have a look at the following:</para> + +<itemizedlist> + +<listitem><para>a bash binary +with debugging symbols: 1200 KB</para></listitem> + +<listitem><para>a bash binary +without debugging symbols: 480 KB</para></listitem> + +<listitem><para>Glibc and GCC files (/lib and /usr/lib) +with debugging symbols: 87 MB</para></listitem> + +<listitem><para>Glibc and GCC files +without debugging symbols: 16 MB</para></listitem> + +</itemizedlist> + +<para>Sizes may vary somewhat, depending on which compiler was used and which C +library, but when comparing programs with and without debugging symbols the +difference will generally be a factor between 2 and 5.</para> + +<para>As most people will probably never use a debugger on their system +software, a lot of disk space can be regained by removing these symbols. For +your convenience, the next section shows how to strip all debugging symbols +from all programs and libraries. Information on other ways of optimizing your +system can be found in the hint at <ulink +url="&hints-root;optimization.txt"/>.</para> + +</sect1> + + +<sect1 id="ch-system-strippingagain"> +<title>Stripping again</title> +<?dbhtml filename="strippingagain.html" dir="chapter06"?> + +<para>If you are not a programmer and don't plan to do any debugging on your +system software, you can shrink your system by about 200 MB by removing the +debugging symbols from binaries and libraries. This causes no inconvenience +other than not being able to debug the software fully any more.</para> + +<para>Most people who use the command mentioned below don't experience any +problems. But it is easy to make a typo and render your new system unusable, so +before running the strip command it is probably a good idea to make a backup of +the current situation.</para> + +<para>If you are going to perform the stripping, special care is needed to +ensure you're not running any of the binaries that are about to be stripped. +If you're not sure whether you entered chroot with the command given in +<xref linkend="ch-system-chroot"/>, then now exit from chroot and reenter it +with the following commands:</para> + +<screen><userinput>logout; chroot $LFS /tools/bin/env -i \ + HOME=/root TERM=$TERM PS1='\u:\w\$ ' \ + PATH=/bin:/usr/bin:/sbin:/usr/sbin \ + /tools/bin/bash --login</userinput></screen> + +<para>Now you can safely strip the binaries and libraries:</para> + +<screen><userinput>/tools/bin/find /{,usr/}{bin,lib,sbin} -type f \ + -exec /tools/bin/strip --strip-debug '{}' ';'</userinput></screen> + +<para>A large number of files will be reported as having their file format not +recognized. These warnings can be safely ignored, they just mean that those +files are scripts instead of binaries, no harm is done.</para> + +<para>If you are really tight on disk space, you may want to use +<emphasis>--strip-all</emphasis> on the binaries in +<filename>/{,usr/}{bin,sbin}</filename> to gain several more megabytes. But do +<emphasis>not</emphasis> use this option on libraries: they would be +destroyed.</para> + +</sect1> + + <sect1 id="ch-system-revisedchroot"> <title>Revised chroot command</title> <?dbhtml filename="revisedchroot.html" dir="chapter06"?> -<para>From now on when you exit the chroot environment and wish to re-enter +<para>From now on when you exit the chroot environment and wish to reenter it, you should run the following modified chroot command:</para> <screen><userinput>chroot $LFS /usr/bin/env -i \ @@ -521,8 +608,5 @@ just yet. There is still some use for it towards the end of the book.</para> </sect1> - -&c6-aboutdebug; - </chapter> diff --git a/chapter08/kernel.xml b/chapter08/kernel.xml index 87d533864..5f1f69d8d 100644 --- a/chapter08/kernel.xml +++ b/chapter08/kernel.xml @@ -74,6 +74,11 @@ interest to you.</para> <screen><userinput>make CC=/opt/gcc-2.95.3/bin/gcc modules_install</userinput></screen> +<para>If you have a lot of modules and very little space, you may want to +consider stripping and compressing the modules. For most people such compression +isn't worth the trouble, but if you're really pressed for space, then have a look at +<ulink url="http://www.linux-mips.org/archives/linux-mips/2002-04/msg00031.html"/>.</para> + <para>As nothing is complete without documentation, build the manual pages that come with the kernel:</para> diff --git a/chapter09/theend.xml b/chapter09/theend.xml index 52bf6f6e8..e154f0513 100644 --- a/chapter09/theend.xml +++ b/chapter09/theend.xml @@ -6,50 +6,6 @@ been a long process, but we hope it was worth it. We wish you a lot of fun with your new shiny custom built Linux system.</para> -<para>Now would be a good time to strip all debug symbols from -the binaries on your LFS system. If you are not a programmer and don't plan -on debugging your software, then you will be happy to know that you can -reclaim a few tens of megs by removing debug symbols. This process causes -no inconvenience other than not being able to debug the software fully -anymore, which is not an issue if you don't know how to debug.</para> - -<para>Disclaimer: 98% of the people who use the command mentioned below don't -experience any problems. But do make a backup of your LFS system before -you run this command. There's a slight chance it may backfire on you and -render your system unusable (mostly by destroying your kernel modules -and dynamic & shared libraries). This is caused more often by typos -than by a problem with the command used.</para> - -<para>Having said that, the --strip-debug option we use to strip is quite -harmless under normal circumstances. It doesn't strip anything vital from -the files. It also is quite safe to use --strip-all on regular programs -(don't use that on libraries - they will be destroyed), but it's not as -safe, and the space you gain is not all that much. But if you're tight on -disk space every little bit helps, so decide for yourself. Please refer to -the strip man page for other strip options you can use. The general idea -is to not run strip on libraries (other than --strip-debug), just to be -on the safe side.</para> - -<para>If you are planning to go ahead and perform the strip, special care is -needed to ensure you're not running any binaries that are about to be stripped --- including the active bash shell. Therefore you'll need to exit the chroot -environment and reenter it using a modified chroot command:</para> - -<screen><userinput>logout -chroot $LFS /tools/bin/env -i \ - HOME=/root TERM=$TERM PS1='\u:\w\$ ' \ - PATH=/bin:/usr/bin:/sbin:/usr/sbin \ - /tools/bin/bash --login</userinput></screen> - -<para>Now run the following command:</para> - -<screen><userinput>/tools/bin/find /{,usr/,usr/local/}{bin,sbin,lib} -type f \ - -exec /tools/bin/strip --strip-debug '{}' ';'</userinput></screen> - -<para>Quite a number of files will be reported as having their file format not -recognized. Most of these are scripts instead of binaries. These warnings can -be safely ignored.</para> - <para>It may be a good idea to create an <filename>/etc/lfs-release</filename> file. By having this file it is very easy for you (and for us if you are going to ask for help with something at some point) to find out which LFS version |