The 'copy yourself out of the way' elfboot code was incredibly powerful and fun to read. It was also tricky.
For the first pass, I yanked it from v3 as I had too many 'what the hell is this doing' questions over the years. It reduced from 668 tricky lines to 215 dead-simple lines. But we also lost the ability to run arbitrary code. That ability was almost never needed, however.
It would actually be simpler, if we want arbitrary ability to to copy code around, to put a final 'copy it around' function in ROM, run all stages of LinuxBIOS, and run the 'copy it all around' bit in ROM.
Or: We do several uncompress lar to rom, run, return to rom phases now, The final copy step could be a final lar entry.
There are actually lots of ways to do support arbitrary code destination, all of them simpler than what we did in V2. I'd like to explore alternatives before we put the v2 code back.
thanks
ron