This weekend I had a play with getting a kernel to boot on my PowerBook Duo
250.

The sources which I supped on Saturday can drive the internal video of this
machine, but it hangs very early on in the bootstrap routines.

By adding debugging printf statements through the early stuff, I've found that
the kernel is hanging in get_pte() in locore.s

Daishi Kato suggested a possible fix for this, by changing the code to use the
tt1 register instead of tt0.

i.e. change .long 0xf0100800 to .long 0xf0100c00 in locore.s

I made this mod and rebuilt, but the resulting kernel still hangs in get_pte().

Does anyone have any other suggestions? I'm afraid I have no 68k assembler
knowledge at all, so this code is a complete mystery to me.

Bernard.