Yes the posion in rom
just need to make sure entry/failover is in 64k limit. So enable_rom in
failover can be executed.
Progress however unless I am mistaken this will fail
miserably on an 8111 that only enables 64KiB of ROM by default.
I think all of failover.c needs to be put in the magic
position, if we are going to allow arbitrary memory size code.