The guys over at PS2dev have been for ages working on Linux for the PS2, today a kernal loader was released by Megaman

I have a new kernelloader release 1.0.
Now I have also a binary release it can load kernel and initrd from USB memory stick or ps2 memory card.

http://mitglied.lycos.de/ps2dev/kern....0/kloader.elf

Added
Here are files that can be used for testing:
http://mitglied.lycos.de/ps2dev/vmlinux
http://mitglied.lycos.de/ps2dev/initrd.gz