Glibc installation Before starting to install glibc, you must cd into the glibc-&glibc-version; directory and unpack glibc-linuxthreads inside the glibc-&glibc-version; directory, not in /usr/src as you normally would do. This package is known to behave badly when you have changed its default optimization flags (including the -march and -mcpu options). Glibc is best left alone. Therefore, if you have defined any environment variables that override default optimizations, such as CFLAGS and CXXFLAGS, we recommend unsetting or modifying them when building Glibc. You have been warned. Basically, compiling Glibc in any other way than the book suggests is putting your system at very high risk. We'll start by applying a patch to Glibc that fixes the following: It converts all occurrences of $(PERL) to /usr/bin/perl in the malloc/Makefile file. This is done because Glibc can't autodetect the location of perl because the Perl package hasn't been installed yet. It replaces all occurrences of root with 0 in the login/Makefile file. This is done because Glibc itself isn't installed yet and therefore username to userid resolving isn't working yet, so a chown root file will fail, however it'll work fine if you use the numeric IDs (such as chown 0 file). patch -Np1 -i ../glibc-&glibc-rootperl-patch-version;-root-perl.patch There is a potential problem that causes statically linked binaries to crash that were linked against Glibc-2.2 or older libraries. Even though static binaries have all the necessary parts of Glibc built-in, they still rely on one external library: Glibc's NSS libraries. These libraries, among other things, tell programs where the system's password database is (/etc/password, or NIS, or whatever other scheme has been configured). Glibc has undergone some changes since version 2.2.x and the new NSS code is incompatible with the old one. So when Glibc is installed, it will install its new NSS libraries and static programs will load these new NSS libraries and start to abort with segmentation faults. This patch undoes a few of the changes to overcome the problem. So, if you started chapter 5 with a host system that uses Glibc-2.2.x or older, you must apply the following patch. We will install Glibc again at the end of this chapter to remove this patch so you'll have a pristine Glibc as the developers intended it. patch -Np1 -i ../glibc-&glibc-libnss-patch-version;-libnss.patch Glibc will check for the /etc/ld.so.conf file and abort with an error if the file is missing, so we must create it. touch /etc/ld.so.conf It is recommended by the Glibc installation documentation to build Glibc outside of the source directory in a dedicated directory. mkdir ../glibc-build && cd ../glibc-build Next, prepare Glibc to be compiled. ../glibc-&glibc-version;/configure --prefix=/usr \     --disable-profile --enable-add-ons \     --libexecdir=/usr/bin During this stage you will see the following warning:
configure: warning: *** These auxiliary programs are missing or too old: msgfmt *** some features will be disabled. *** Check the INSTALL file for required versions.
The missing msgfmt (from the gettext package which we will install later in this chapter) won't cause any problems. msgfmt is used to generate the binary translation files that are used to make your system talk in a different language. Because these translation files have already been generated for you, there is no need for msgfmt. You'd only need msgfmt if you change the translation source files (the *.po files in the po subdirectory) which would require you to re-generate the binary files. The meaning of the configure options are: --disable-profile: This disables the building of libraries with profiling information. This command may be omitted if you plan to do profiling. --enable-add-ons: This enables the add-on that we install with Glibc, linuxthreads --libexecdir=/usr/bin: This will cause the pt_chown program to be installed in the /usr/bin directory. Because Glibc hasn't been installed yet, one of the tests that was run by the configure script failed. This test is supposed to test gcc to determine whether or not a cross-compiler is installed. However, Glibc needs to be installed already to run this test. Since the test failed, the configure script automatically assumed we do have a cross-compiler. So, we have to override that assumption by explicitly telling Glibc we're not cross-compiling. echo "cross-compiling = no" > configparms We'll continue with compiling and installing Glibc. The Linuxthreads man pages are not going to be installed at this point because it requires a working Perl installation. We'll install Perl later on in this chapter, and the man pages will be installed when Glibc is installed for the second time at the end of this chapter. make && make install Locales aren't installed when you ran make install, so we have to do that ourselves now. Locales are used by Glibc to make your Linux system talk in a different language. make localedata/install-locales An alternative to running make localedata/install-locales is to only install those locales which you need or want. This can be achieved using the localedef command. Information on this can be found in the INSTALL file in the glibc-&glibc-version; tree. To finish off the installation we'll reload Bash so it uses the libnss files. This will also get rid of the I have no name! message in the command prompt. exec /static/bin/bash --login