🚀 go-pugleaf

In article <JsgkuB1w165w@salzo.Cary.NC.US> David Burton,
dburton@salzo.Cary.NC.US writes:
>The CPU in my notebook computer consumes much less power (i.e., goes
>into a standby mode) when executing a HLT (halt) instruction.  I've
>written a little utility that can tell when the CPU is being little-
>utilized, and it slows down the clock to save power when it detects
>that situation.  However, it would save even more if it executed the
>HLT instruction.  That'd be no problem except that...
> 
>...the darn HLT instruction is privileged.
> 
>Of course, there is no good reason for it to be privileged... it is no
>more "dangerous" than "JMP $".  However, Intel goofed (and Cyrix 
>dutifully
>cloned the goof), so there's nothing that I can do about it.

Yes indeed there is a good reason for the HLT instruction being
privledged! Allowing an application to perform HLTs would seriously
jepordize system security.  Of course I realize this is immaterial to
you in the situation you described, but if the os is running a task
which controls Aunt Mille's iron lung, I'd like to have some assurance
a cute little utility downloaded from some BBS can't execute a HLT.

---
Creed Erickson