In this chapter we enter the building site, and start constructing our LFS system in earnest. That is, we chroot into our temporary mini Linux system, create some auxiliary things, and then start installing all the packages, one by one.
The installation of all this software is pretty straightforward, and you will probably think it would be much shorter to give here the generic installation instructions and explain in full only the installation of those packages that require an alternate method. Although we agree with that, we nevertheless choose to give the full instructions for each and every package, simply to minimize the possibilities for mistakes.
The key to learning what makes a Linux system work is to know what each package is used for and why the user (or the system) needs it. For this purpose for every installed package a summary of its content is given followed by concise descriptions of each program and library it installed.
If you plan to use compiler optimizations in this chapter, take a look at the optimization hint at http://www.linuxfromscratch.org/hints/downloads/files/optimization.txt. Compiler optimizations can make a program run slightly faster, but they may also cause compilation difficulties and even problems when running the program. If a package refuses to compile when using optimization, try to compile it without optimization and see if the problem goes away. Even if the package does compile when using optimization, there is the risk it may have been compiled incorrectly due to complex interactions between the code and build tools. In short, the small potential gains achieved in using compiler optimization are generally outweighed by the risk. First time builders of LFS are encouraged to build without custom optimizations. Your system will still be very fast and very stable at the same time.
The order in which packages are installed in this chapter has to be strictly followed, to ensure that no program gets a path referring to /tools hard-wired into it. For the same reason, do not compile packages in parallel. Compiling in parallel may save you some time (especially on dual-CPU machines), but it could result in a program containing a hard-wired path to /tools, which will cause the program to stop working when that directory is removed.
Before the installation instructions each installation page gives some information about the package: a concise description of what it contains, approximately how long it will take to build it, how much disk space it needs during this building process, the official download location of the package (in case you just want to update a few of them), and which other packages it needs in order to be built successfully. After the installation instructions follows a list of programs and libraries that the package installs, together with a series of short descriptions of these.
If you wish to keep track of which package installs what files, you may want to use a package manager. For a general overview of package managers have a look at http://www.linuxfromscratch.org/blfs/view/cvs/introduction/important.html. And for a package management method specifically geared towards LFS see http://www.linuxfromscratch.org/hints/downloads/files/more_control_and_pkg_man.txt.