Hi Peter,
Try making the kernel into an elf and booting that directly, perhaps?
That was the first thing I tried but it didn't work, although now I know about adding the proper signature/loader near the front of the ELF file I might try it again.
I actually got it to work late last night, it turns out I hadn't specified the section load address correctly in the linker script when I was embedding the kernel image into FILO - once I did that it detected the kernel and loaded it. Yay!
It was a pretty roundabout way of getting the kernel image into the FILO ELF file though:
http://sources.redhat.com/ml/ecos-discuss/2002-02/msg00422.html
(modified from ARM to i386, of course.) Is this the only way of embedding a binary file into an ELF image?
Thanks, Adam.