The key difference between
mkelfimage and the aging mknbi is that
mkelfimage does not reply upon any traditional BIOS call to produce the bootable code in the ELF image, which makes it possible to boot thin clients with LinuxBIOS as their firmware, such as the Linuterm and several other products designed by Artec.
mkelfimage accomplishes its BIOS-less operation using a simplified
kexec implementation. However, this also means that explicit support for each architecture must be implemented with Assembler code. As it currently stands, the upstream tarball only includes support for
amd64 boots in 32-bit mode, it should also work there, but this is untested.
This leaves support for several architectures completely uncovered for. LinuxBIOS developers have taken over the upstream code and they welcome patches towards improving support for other architectures and towards cleaning up the autoconf implementation currently in use.