There's the Interim OS project [1] (already discussed in another comment here) as a bare-metal Lisp and it might be interesting to port Movitz [2], a bare-metal Lisp project for x86 that seems to be abandoned for quite some time now.
There also seems to be a bare metal Forth implementation, pijFORTHos [3], but I haven't played around with that one so far.
There also seems to be a bare metal Forth implementation, pijFORTHos [3], but I haven't played around with that one so far.
[1] http://interim-os.com/ [2] https://en.wikipedia.org/wiki/Movitz [3] https://github.com/organix/pijFORTHos