> >
> > > In addition, the user programs could be protected from the kernel
> and vice
> > > versa...
>
> Note, without memory protection we really have no lower priviledged users,
> all users
> are the equivelent of root. Users exist merely to provide some logical
> division.
[<Simon Wood>]
Not 100% true, if a program behaves then the kernel can prevent inspection
of privileged data. It's only when a program miss-behaves the trouble
starts.
FYI
The Psion 3a have a simple memory protection of a range of address that the
program may write to, if a write outside these is attempted then an
interrupt is trigger - I will probably attempt to use this once I have code.
However it is possible for a malicious program (i.e. the stuff I have done
so far) to defeat this.
Simon W.
