Linux From Scratch - Requirements and Procedure

Requirements and Procedure

A clean partition and a working Linux system with a compiler and some essential software libraries are required to build LFS. Instead of installing from an existing Linux system, one can also use a Live CD to build an LFS system.

Formerly the project maintained the Linux From Scratch Live CD. LFS Live CD contains all the source packages (in the full version of the Live CD only), the LFS book, automated building tools and (except for the minimal Live CD version) an Xfce GUI environment to work in. The LFS Live CD is no longer maintained, and cannot be used to build the current version (7) of LFS.

First a toolchain must be compiled consisting of the tools used to compile LFS like GCC, glibc, binutils and other necessary utilities. Then the root directory must be changed (using chroot) to the toolchain's partition to start building the final system. One of the first packages to compile is glibc; after that, the toolchain's linker must be adjusted to link against the newly built glibc, so that all other packages that will make up the finished system can be linked against it as well. During the chroot phase, bash's hashing feature is turned off and the temporary toolchain's bin directory moved to the end of PATH. This way the newly compiled programs come first in PATH and the new system builds on its own new components.