If all else fails, it should be possable to generate an image by just concatenating the etherboot .elf binary, some padding, and the two linuxbios.strip binaries together.
The _two_ linuxbios.strip binaries? I only see the one in my build tree. I was going to try and use mkflashimg but I think I need a DoC bit or two I haven't figured out yet. :-)
recent objdump (that supports i8086 arch) with -D (disassemble all) can help to see where the pieces should go. Just remember that the top of the rom will appear at f0000 at boot time in real mode. Once it gets through __protected_start, you'll be up at the top of memory in i386 arch (ffffxxxx or in primary linuxbios at fffexxxx). One of these days, I'll need to write this up :-)
:-) I am an old x86 hacker (real and protected modes), but I haven't actively used my old knowledge for several years. It's embarassing how much I've lost. I will do what I can along the way to try and document it as I (re)learn it (especially the boot process that LinuxBIOS takes).
Regards, Andrew