Stub code is in the low parts of the low banks and the top of the high banks
so we have two copier routines one for each half.
+ - Fix signal handling crashes
+ - Sometimes we seem to pre-empt in the middle of a pre-empt
+ and crash ?? we see a kprintf from an interrupt interrupted
+ Need to check all our IRQ save/restore logic is sound on
+ video especially !
+ - AtomIDE detect fails if ROM present (select dev 0 first ?)
+DONE - Run out of pages - suggests child exit/bank32 isn't cleaning
+ up right
DONE - Move fonts to video bank after frame buffer
- Floppy driver (at least for read)
DONE - Get to init (but not much further)