[En-Nut-Discussion] H8 HTC port

[Tyou]

I am portting nut to H8/3069F, by now two threads can be run in hitachi simulator.
(today I will test the kernal in hardware) thread.c, event.c, heap.c, nutinit.c
and other some header files has been modified, that means the os kernel has
been ported.
but I have some question.
1. what is the difference of the file heap.c in os folder and the other in mod
   folder?
2. Since nut is not a preemptive os, is it necessory to make heap codes critical?
   And further more, in context switching is it necessory to save all the registers?