> > Yes, fine by me, but I think we should also state that any SWI made
> > *directly* from thumb code is handled "as if" it were done as SYS_syscall
> > (except that the immediate field of the thumb swi instruction is not used).
> 
> Something like that is probably a good idea.  The only thing to be
> careful about is that we can implement a __syscall() veneer in this case.

Not really necessary, since we can just say "use the ARM variant for this 
case".

I don't think there will be many cases where we will need to call a SWI 
directly from thumb.  Indeed the only case I can readily think of is the 
compiler generating an IMB (for which it would be tricky to make it switch 
into and out of ARM mode).

R.