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Linux From Scratch (LFS)

What is LFS?

Linux From Scratch (LFS) is a project that provides instructions for building your own custom Linux operating system directly from source code.

It is designed for Linux users who want to gain a deeper understanding of the inner workings of the operating system.

These notes will document building my own Linux operating system by using LFS as a base. The OS will use common enterprise technologies (e.g., systemd) rather than more obscure tools. I made this choice to gain a deeper understanding of the OS components used in enterprise environments.

Starting Out

LFS follows Linux standards as closely as possible.

The standards followed:

The core packages that are included in a system built to the LFS standard are listed here along with explanations on why they were included.

Setting up the Build Environment

The LFS project is built within a pre-existing Linux system.
A disk partition is made for the LFS filesyste and that's where the new OS is going to be built.

The list of dependencies for builting an LFS system can be found here.

They provide a shell script on that page that checks for the dependencies on the host system and ensures they're on the correct versions.

For chapters 1-4:

  • Anything done as the root user after Section 2.4 must have the LFS environment variable set FOR THE ROOT USER.

  • The LFS variable must be set at all times, and the umask needs to be set to 0022.

For chapters 5-6:

  • The partition should be at /mnt/lfs and always be mounted.

  • Chapters 5 and 6 must be done as the lfs user system account.

    • Create the lfs user and group.
    • Use su - lfs for each task in these chapters.

For chapters 7-10:

  • /mnt/lfs should be mounted.

Resources