Minlin Linux ISO builder by John Jolly

Here is my build process for creating a bootable Linux ISO with two files:

• The Linux kernel
• Busybox

It is the smallest distribution I can find, although I suspect someone will or may already have made a smaller distro. I'm not in a race and I'm always interested it what people can do.

The initial submission was written in a fit of unhealthy madness the night of 26-27 March 2025. Who needs sleep?

How

Currently the image builds everything, then copies the iso into a folder on your host when you create the container like this:

docker run --rm -v `pwd`/iso:/minlin/iso jjolly/minlin

Of course you want to create the folder you want the iso to land in. If you don't supply a volume mapping, the iso will be copied to the /minlin/iso folder inside the quickly-deleted container. Kind of useless, so use a volume map.

Want to boot the image? Then install qemu-system-x86 and run this command:

qemu-system-x86_64 -cdrom iso/minlin.iso -nographic

Want to experience a kernel panic? Exit the shell. That's how raw this is.

What

I'm building a very low-feature kernel starting with making the allnoconfig target and adding what I need to make this work. There are a few extra files that help add necessary functionality and might need a little explanation:

• x86_64_min.config: This file adds kernel config options to allow the kernel to load 64-bit ELF-formatted executables using the init script.
• initramfs_xz.config: This adds kernel config options that allow the kernel to use an initrd that is compressed with xz.
• init: This is the init script mentioned earlier.
• grub.cfg: This gives me boot options for the iso image.

When

I have plans for this. I'd like to actually perform the build process on your machine. When you start the container, all the files will already be downloaded. A script will start the kernel and busybox builds, then package it up into an ISO. That's a future-John project, though.

Why

I've done this once already, waaay back in 2016. The old one no longer works and I've since lost the Dockerfile as I didn't take Github seriously then. Now I do. Archive all the things! This is my penance. Now it works as of v6.14 of the Linux kernel.

Who

Most of this is from the wonderful post by Hirbod Behnam. I've made my own changes, but this article does 90% of the heavy lifting.

Next

• Slim down grub. It's over half the final ISO. That's just wrong
• arm64 support. Heck, let's do all the architectures!
• Test on real hardware
• Put the build part into a script and let that happen when the container is run
• Fix the Busybox build system (outside the scope of this project)