[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Re: [f-cpu] More Dark and Dusty Corners
Quick reply...
On Tue, Sep 04, 2001 at 11:08:28PM +0200, whygee@club-internet.fr wrote:
[...]
> >> > According to the manual, the running SRB must finish before a new one
> >> > can be started, but that's not appropriate -- why finish something you
> >> > have to undo anyway?
>
> it is because when it returns, it would be very complicated
> to know if the register was saved or something like that.
>
> In fact i think that i remember : If you interrupt one SRB
> by another, we can't know which register belongs to what.
[...]
Hmm... gotta think that over.
But there still are open questions. Is a context switch *one* SRB, or
two (save/reload) in sequence? Do the "events"
- syscall instruction
- trap instruction
- rfe instruction
- external interrupt
- exception/fault
cause a context switch, or do they only save (or restore, in case of
rfe) the registers? And where does the *new* CMB pointer come from
if a second event occurs while the SRB from the first is still active
(which probably triggers a second SRB)?
--
Michael "Tired" Riepe <Michael.Riepe@stud.uni-hannover.de>
"All I wanna do is have a little fun before I die"
*************************************************************
To unsubscribe, send an e-mail to majordomo@seul.org with
unsubscribe f-cpu in the body. http://f-cpu.seul.org/