you need to create a linuxboot.cfg file and put that file in the root of cdrom like this:
QUOTE
kernel isolinux/fatximage
initrd isolinux/initrd.gz
append root=/dev/ram3 ramdisk_size=36000 automatic=method:cdrom
but you wont be able to load it right cz the initrd file is itself 25MB uncompressed and when that dunps into RAm.. xbox's 64 mb ram isnt enough.