sommerfeld@orchard.arlington.ma.us said:
> Hmm.  Is there any reason why the kernel has to be resident in the
> sub-16M "prime real estate" on large-memory x86 systems? 

Simplicity I think.
It would need some nasty runtime decisions to make one kernel
run on small and large memory systems. The bootloader is
affected too.
Also, the kernel not following the ISA hole would imply
another memory fragment, slowing down vm_page lookups.
(Don't know how much this matters.)

best regards
Matthias