On Tuesday 06 March 2001 11:53 pm, Ben Harris wrote:
> On Tue, 6 Mar 2001, Chris Gilbert wrote:
> > > NB. the code in question could be made safer by adding a check for the
> > > cpu class (which could be set up during boot).
> >
> > Yep, I suppose the way to do it is to have an arm7 swi handler, just be a
> > matter of setting up the zero page differently.
>
> I still don't see why this is necessary.  Is it expected that future ARMs
> will define new instructions that will take the SWI trap, or something?
> Even if they do, the worst that will happen is that the new instructions
> will cause the process to loop rather than catching a SIGILL, and I hardly
> think that's an immediate cause for concern.

Doh, light bulb illuminates.  Yes of course only a SWI should end up in that 
code, anything else going there is just daft if it didn't just use SWI   
(other than fun and games with the broken arm7)

I suppose you could claim efficiency for other cpu's by having an arm7 
specific handler in a kernel for multiple cpu versions.  but it's not needed, 
and would just add unneeded bloat to the kernel.

Cheers,
Chris