Linux From Scratch - Version 6.3

Chapter 5. Constructing a Temporary System

5.6. Glibc-2.5.1

The Glibc package contains the main C library. This library provides the basic routines for allocating memory, searching directories, opening and closing files, reading and writing files, string handling, pattern matching, arithmetic, and so on.

Approximate build time: 7 SBU
Required disk space: 342 MB

5.6.1. Installation of Glibc

The Glibc documentation recommends building Glibc outside of the source directory in a dedicated build directory: 

mkdir -v ../glibc-build
cd ../glibc-build

Next, prepare Glibc for compilation: 

../glibc-2.5.1/configure --prefix=/tools \
    --disable-profile --enable-add-ons \
    --enable-kernel=2.6.0 --with-binutils=/tools/bin \
    --without-gd --with-headers=/tools/include \
    --without-selinux

The meaning of the configure options:

--disable-profile

This builds the libraries without profiling information. Omit this option if profiling on the temporary tools is necessary.

--enable-add-ons

This tells Glibc to use the NPTL add-on as its threading library.

--enable-kernel=2.6.0

This tells Glibc to compile the library with support for 2.6.x Linux kernels.

--with-binutils=/tools/bin

While not required, this switch ensures that there are no errors pertaining to which Binutils programs get used during the Glibc build.

--without-gd

This prevents the build of the memusagestat program, which insists on linking against the host's libraries (libgd, libpng, libz, etc.).

--with-headers=/tools/include

This tells Glibc to compile itself against the headers recently installed to the tools directory, so that it knows exactly what features the kernel has and can optimize itself accordingly.

--without-selinux

When building from hosts that include SELinux functionality (e.g., Fedora Core 3), Glibc will build with support for SELinux. As the LFS tools environment does not contain support for SELinux, a Glibc compiled with such support will fail to operate correctly.

During this stage the following warning might appear: 

configure: WARNING:
*** These auxiliary programs are missing or
*** incompatible versions: msgfmt
*** some features will be disabled.
*** Check the INSTALL file for required versions.

The missing or incompatible msgfmt program is generally harmless, but it can sometimes cause issues when running the test suite. This msgfmt program is part of the Gettext package which the host distribution should provide. If msgfmt is present but deemed incompatible, upgrade the host system's Gettext package or continue without it and see if the test suite runs without problems regardless.

Compile the package: 

make

Compilation is now complete. As mentioned earlier, running the test suites for the temporary tools installed in this chapter is not mandatory. To run the Glibc test suite (if desired), the following command will do so: 

make check

For a discussion of test failures that are of particular importance, please see Section 6.9, “Glibc-2.5.1.”

In this chapter, some tests can be adversely affected by existing tools or environmental issues on the host system. Glibc test suite failures in this chapter are typically not worrisome. The Glibc installed in Chapter 6 is the one that will ultimately end up being used, so that is the one that needs to pass most tests (even in Chapter 6, some failures could still occur, for example, with the math tests).

When experiencing a failure, make a note of it, then continue by reissuing the make check command. The test suite should pick up where it left off and continue. This stop-start sequence can be circumvented by issuing a make -k check command. If using this option, be sure to log the output so that the log file can be examined for failures later.

The install stage of Glibc will issue a harmless warning at the end about the absence of /tools/etc/ld.so.conf. Prevent this warning with: 

mkdir -v /tools/etc
touch /tools/etc/ld.so.conf

Install the package: 

make install

Different countries and cultures have varying conventions for how to communicate. These conventions range from the format for representing dates and times to more complex issues, such as the language spoken. The “internationalization” of GNU programs works by locale.

[Note]

Note

If the test suites are not being run in this chapter (as per the recommendation), there is no need to install the locales now. The appropriate locales will be installed in the next chapter. To install the Glibc locales anyway, use instructions from Section 6.9, “Glibc-2.5.1.”

Details on this package are located in Section 6.9.4, “Contents of Glibc.”