http://www.execpc.com/~geezer/osd
I didn't get as far with this as I wanted. A lot of this code
is borrowed from my Cosmos OS, but Cosmos has some ugly things
that shouldn't be put into OS code meant as a tutorial.
This code now boots with GRUB. Since GRUB doesn't really
support real-mode kernels, I can no longer demonstrate how
to enter pmode. Oh well.
The Linux/ELF version of OSD9 crashes. I don't yet know why.
The DJGPP version works OK.