The first level boot blocks have understood how to load ELF code since
1999. Switch /boot/loader and /boot/pxeldr over to being ELF format so
that in-tree tools can examine them more closely. In addition, one
could, in theory, now have a 'lo-mem' and a 'hi-mem' segment (though a
lot of work would need to be done with bounce buffers, btx, code segment
marking, etc for an arrangement like that to work).
As far as I can tell, this is the last a.out binary in the tree. There
are several raw binaries left, but everything else is ELF.
Reviewed by: emaste, kevans
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D36130
e2295b9117