Hi, All,
Regarding question 2, I searched ARM's WWW site and found nothing.
Could somebody help me to get the related document that tell about ARM's
protect mechanism.
Also, Thanks for Yves Rutschle's answer.
Appreciate!
> >(1). Could somebody tell me what's different for SYSTEM mode and
SUPERVISOR
> mode
> >for ARM7TDMI?
>
> System mode is like user mode except all operations are permitted.
> Alternatively,
> System mode is like supervisor mode except you work with user mode
> registers.
>
> System mode is usually what supervisor mode falls into when it needs to
> change
> something in the user mode (because you can go back to supervisor mode
> from
> system mode. If you went to user mode, you'd be stuck there as user mode
> can't change the mode back to supervisor).
>
> (this is valid for any ARM core, by the way)
>
> >(2). Does ARM7TDMI mplement a hardware mechanism to detect memory
violation?
> > I mean if I have a program that run in user mode nad the
> program try
> >to access the system mode's data.
> > Can hardware tell me memory violation? Or I must have a mechanism
> >in software to access the violation?
>
> I am not sure you can implement any kind of protection that would be
> purely
> software. Anyway, all ARM7 cores have some sort of protection mecanisms.
> The
> details depend on the actual core (some have full fledged MMU, others
> only
> a basic protection unit). You should be able to find details on the
> memory system for your particular core on ARM's site.
>
> Cheers,
> Y.
>
>
_______________________________________________
http://lists.arm.linux.org.uk/mailman/listinfo/linux-arm
Please visit the above address for information on this list.
