I found a couple of interesting things on Freshmeat today.
First, there’s a Linux-bootfloppy-from-scratch hint, in the spirit of Linux From Scratch, but using uClibc and Busybox in place of the full-sized standard GNU userspace. This is great for low-memory, low-horsepower machines like 386s and 486s.

I would think it would provide a basis for building small Linux distributions using other tools as well.

What other tools? Well, there’s skarnet.org, which provides bunches of small tools. The memory usage on skarnet’s web server, not counting the kernel, is 2.8 megs.

Skarnet’s work builds on that of Fefe, who provides dietlibc (yet another tiny libc) and a large number of small userspace tools. (These tools provide most of the basis for DietLinux, which I haven’t been able to figure out how to install, sadly. Some weekend I’ll sign up for the mailing list and give it another go.

And then there’s always asmutils, which is a set of tools written in pure x86 assembly language and doesn’t use a libc at all, and the e3 text editor, a 12K beauty that can use the keybindings for almost every popular editor, including two editors that incite people into religious wars.

These toolkits largely duplicate one another but not completely, so they could be complementary.

If you want to get really sick, you can try matching this kind of stuff up with Linux-Lite v1.00, which is a set of patches to the Linux 1.09 kernel dating back to 1998 or so to make it recognize things like ELF binaries. And there was another update in 2002 that lists fixes for the GCC 2.72 compiler in its changelog. I don’t know how these two projects were related, if at all, besides their common ancestry.

Or you could try using a 1.2 kernel. Of course compiling those kernels with a modern compiler could also be an issue. I’m intrigued by the possibility of a kernel that could itself use less than a meg, but I don’t know if I want to experiment that much.

And I’m trying to figure out my fascination with this stuff. Maybe it’s because I don’t like to see old equipment go to waste.