Linux from Scratch (linuxfromscratch.org)

It was like automated LFS from git

FreeBSD’s Makefile system is also in this ballpark

It’s on my list of things to do when I have some free time

I mean, eh... last time I checked, this was Hacker news. Yesterday, there was an Ask HN topic on how to enable dark mode on HN. Is this the new hacker culture? Complaining that the resources merely point in some direction instead of specifying details?

Principles can be studied from “Operating Systems: Three Easy Pieces“ book - https://pages.cs.wisc.edu/~remzi/OSTEP/

Rob Love wrote the book “Linux Kernel Development”. https://rlove.org/

And then continue with reading LFS.

So at points you want to dive deeper, you do — and go off the beaten path.

It requires a desire not just to understand how bits and pieces fit together, but how you can make them work even better for yourself and what is and is not customizable?

Arguably, even if building it today is easier — back when I did it in 2000, you sometimes struggled to find where the canonical source code of the package is, not to mention compilation errors, linking errors, etc. Only then did you get to configuring the init RC system, choosing between them (no systemd yet), etc.

But a requirement is — IMO — that you are strongly opinionated about how a system should serve you, and look for opportunities to tune it.

Shameless plug: I started a series of blog posts exactly because this. https://serversfor.dev/linux-inside-out/

Unfortunately due to some cervical spine issues and a surgery I wasn't able to finish it, but I am planning to pick it up and continue.

Most educational resources are what- and how-based, only the best ones are primarily why-based, what Wirth once wrote in the preface to some Pascal book (I paraphrase) 'discussions are motivated, so that the learner gets coverage and understanding, instead of memorization'.

Too bad Cross-LFS is no longer a thing. Then again, with all these microcontrollers and ARM and RISC-V systems today, cross-compiling is no longer as magic (and tricky) as it was back then...

LFS helped me a lot. It taught me how to compile packages manually, and how GNU/Linux components fit together.

Armed with that knowledge, I could do things others could not do:

- Make applications that bundle/automatically download their dependencies, compile them with custom flags (static linking)

- Diagnose build errors buried in deep dependencies when using vcpkg

- Compile programs for esotheric systems: e.g: Intel MacOS X 10.5, an obsolete system noone else on earth is using except the company I worked at

- Create application targetting obsolete systems but using the latest version of its dependencies

- Compile recent programs on esotheric systems, by bootstraping a newer gcc on the newer system, patching as necessary

- Create my own stripped down distro, tuned to my specifications

- Use that stripped distro as a docker container

- Run recent linux on obsolete hardware no longer supported by mainstream distros

- Reformat a cloud dedicated server without physical access by first bootstraping a minimal distro on a ramdisk, unmounting the main drive, partitioning that drive, and installing the new distro on that drive. Reboot and pray.

- Build a cross-compiler for targetting a freestanding environment

- Build latest KDE/XFCE for debian stable. No more "but debian ships with outdated software!!11"

- Build applications on a distro they were not designed for (Zimbra OSE on debian)

That actually makes perfect sense. If you did the bootloader first, how are you going to build it? How do you know what to boot from which filesystem on what device? By the time you've got your root filesystem complete, it's easy to tell.

If you do things step by step incrementally, you keep having to go further back in the process. Starting over repeatedly gets tedious, boring and frustrating. And it'll take ages to finish the complete OS.