dale@amiga.UUCP (Dale Luck) (10/26/85)
The exec library supplies a function 'GetCC()' which returns the value
of the condition codes in d0. This was done because the 68000 does not
have such an instruction but does have the privileged instruction move
from sr. This is guaranteed to work regardless of which processor you have.
The Amiga 1000 currently assumes a 68000 stack frame during address/bus
error processing. Of course you will never run into this problem if you
only write and run perfect code.
The only other time that the stack frame is important is during the
call to Supervisor() if the task is already in supervisor mode then a
68000 style stack frame is created so the supervisor code will rte
correctly. For more information you will have to read the ROM Kernel
manual. This is again a problem that we have never seen surface since
all user code and most of the system software runs in USER mode. None of
the code that we have or used that runs in supervisor mode calls
Supervisor().