This is a complete, self-bootstrapping musl-based Linux system. It
contains nothing more than Linux, Busybox, Binutils, GCC, GMP, MPFR, MPC, and GNU Make. I haven't attempted to minimize the configuration of these (yet), merely the package set. The programs get static-linked, but musl does install a dynamic linker, and GCC should be able to link programs against it.
To build this from a non-musl Linux system, you will need to
execute ./bootstrap.sh. This will build musl and a cross compiler, and then build the system against it, placing the result in ./out.
./make_fs.sh can be used to generate a bootable ext2 filesystem
from the out directory. To use it, you will need the "genext2fs" program installed. If you don't feel like using it, you can just copy the files onto a filesystem of your choice and boot it.
Some todos: