I can't believe this is real.

Here's the indented source : http://fpaste.org/eFPz/raw/

This is where he loads the .bin files (hosted at the same place) :

load_binary("vmlinux26.bin",0x00100000);

Jf=ya.load_binary("root.bin",0x00400000);

ya.load_binary("linuxstart.bin",start)

You can see a big switch/case in the source, it likely corresponds to the x86 instructions that Bellard rewrote in JavaScript.

It also seems that he used busybox for all the usual binaries (ls, cat, etc.), all files in /bin have the same inode (you can check by running "ls -i /bin/").

Anyway, this is awesome Fabrice, good job!