I've been thinking about this for a while. It's not really practical, but just for fun. Essentially rewriting the tools needed for a minimal Linux distro with just the kernel. I found this PyCon presentation(video on Youtube) about this very subject. Unfortunately there's no mention of it past 2006 but oh well. Another use for such a thing would like be similar to Docker but with the build process of SnackLinux.
It's with great success that I can announce SnackLinux has working arm64 build instructions, along with updated x86.
Quick update to SnackLinux, rolled out Linux 4.15.2 with Busybox 1.28.0. Also switched over to x86_64 only (for now at least) since it simplifies a lot of things. I removed the need to staticly link everything and get rid of that niche, since a few other smaller distros cover that (Alpine Linux for example). Again, this simplifies building packages and running into less issues.
The Makefile for SnackLinux has been updated, I made it a bit easier to build SnackLinux from scratch. I'd like to update GCC to at least 5.x something, and add a few more packages to SnackLinux. Eventually, adding a PKGBUILD-like system to fbpkg would be preferable. Right now, it's just a bunch of instructions on the snacklinux.com.
SnackLinux now has a whopping 31 packages, which include a (somewhat) working gcc toolchain and other fun GNU utilities (vitetris included!). I was able to add Docker support as well, which is just tarballed userland. Getting a working gcc toolchain was a bit of a pain in the butt.
For the most part, SnackLinux works. I've been having problems with Busybox, so I've made packages for coreutils, binutils, sed, grep and gawk. When compiling anything, I get:
segfault at 0 ip (null) sp bfdb1cbc error 4 in busybox[8048000+e8000]
Four months later and I finally updated SnackLinux. I changed SnackLinux from a ramdisk to initramfs, updated the Linux 3.10.1 and cleaned up how things build. The full project is available on my Bitbucket and ISOs are available to download here.
I've spent the last week or two working on SnackLinux, a small Linux distro. I managed to get uClibc in there, as well as tcc, which makes it somewhat useful. The source of it all is there, so you can compile the distro yourself (sans the packages). There are also ISOs which you can download here and fire them up in a virtual machine.