This article outlines Swinux club member Zain’s journey building Linux From Scratch, reposted with permission. You can find his blog here.

Contents

Beginnings⌗

So, I was bored, and I was already compiling linux-tkg on my Arch Linux system, so I thought, why not try Gentoo? And then for some reason I ended up going with LFS (Linux From Scratch). help me

Anyways, what follows is the recap of my journey from nothing to a working system in TTY.

Preparation⌗

This was honestly quite straightforward, I gave LFS 30 gigs, and the rest of my system was already correctly partitoned so I didn’t need to do anything else.

Building the Toolchain⌗

I actually did this part 3 times. Firstly I tried doing it manually, but I kept failing, and then I tried it again cleanly, also failed to get it working. But see, I wanted to use musl over glibc, so I then dicovered mussel and it worked beautifully for cross compiling. Not only that but it also compiled libstdc++ and binutils, wow. I copied the toolchain into a /tools directory on my LFS partition and we were set to begin.

A quick heads up before the next section, I wanted uutils over coreutils and runit over systemd, so I deviated from the book quite a lot and as such took assistance from Gemini at multiple points, please don’t get mad at me.

Building the Temporary System⌗

Next was cross compiling some basic tools, it mostly went smooth except for some tools complaining about some features specific to glibc which I had to end up patching for musl to work. I also did spend a lot of time on the stage2 gcc and binutils but eventually got it working. And here we encounter our second battle, rust. Since I wanted uutils I needed rust. Luckily rust supports cross compiling so I just cross compiled the first pass of coreutils, the only issue I really had here was just tryna get rustc to collaborate with the cross compiled GCC but once that worked, we were set up to resolve compiler hell.

Compiler Hell⌗

The LFS book lists 70+ packages to install and installing all of them took a while. They mostly went smoothly minus a few hiccups with glibc assumptions but those were mostly patched out easily. The larger challenge was uutils. I tried compiling rust and clang but slowly gave up when I realised it wasn’t worth my sanity. I ended up using the pre compiled aarch64-unknown-linux-musl rust binaries and they compiled uutils properly. I also took the liberty of installing iwd, curl, and runit while I was at this stage. This whole section was the most time consuming part but we still have 2 more battles to come.

System Config⌗

This was honestly really straightforward cause all I had to do was just ignore the systemd parts from the book. I would be later on configuring runit, so yeah, smooth sailing here.

The Kernel⌗

I already had a .config file that I used when compiling linux-tkg on arch so I would’ve just used that, but Gemini suggested otherwise. So I copied the file over and used make localmodconfig to generate the proper config. I then compiled the kernel, wrote a little initramfs script with busybox of which at this point I managed to statically compile cryptsetup (that was a nightmare to statically link) and then gzipped the initramfs, and at the time copied the generated bzImage over to my arch host system and then used systemd-ukify to create a UKI. I tried booting aaaand nothing. It would just blackscreen. Turns out after a bit of debugging that I had to add initrd=/init to my CMDLINE. Fixed that aaand kernel panic.

Photo of Linux terminal displaying a kernel panic.

Guess what, I forgot to compile some drivers into my kernel and I believe I had some other issues with cryptsetup, a bit of debugging later and it would finally ask me for my LUKS password.

Enter battle, runit.

Runit⌗

So, I compiled runit and installed it, but now whenever I would enter my LUKS password my system would instantly shutdown. I had no idea why, I thought maybe cryptsetup is broken or maybe it’s my init script? I ended up recording a video and caught a frame of access denied for the 3 runit files. I forgot to chmod +x them. After that we then had issues with me incorrectly setting up my runit directory structure for each runit service. I made each script the name of service instead of making the service name a directory and putting a file in it called run. After fixing that, I had iwd issues to deal with. I was missing a bunch of config options from my kernel and some of them were driving me crazy.

Photo taken of Linux terminal displaying iwd configuration errors.

I couldn’t find them, but after about 5 kernel recompiles iwd finally stopped blocking me and we got to a bash prompt. Yay!

Photo taken of Linux terminal with logged in user as bash.

This post has been going on so long, so I’ll end it here and save the WiFi/libreadline battles for part 2. Hope you enjoyed my self-inflicted suffering. See you when I have internet and iwd working!

This post is redistributed from zain-khan.dev with permission from the author. You can find Part 2 once live here.