Upcall handler

Peter Naulls peter at chocky.org
Sat Feb 5 14:40:13 PST 2005

In message <d5fba8384d.ajw498 at caramel.cp15.org>
          Alex Waugh <alex at alexwaugh.com> wrote:

> We could fix at least some of this, however I'm wondering if it would
> be better to simply return from the upcall handler with r0 set to 0,
> and hence refuse to allow the new application to start.

That might be best.  I did look at this issue a long time ago, but
didn't fully appreciate all the problems - probably due to dealing with
other problems.

> I believe the only time the upcall handler gets called for the new
> application upcall is when the user program runs a new program via
> OS_CLI (and only for starting new programs, it won't affect *commands)
> which I don't think is useful functionality given we have the exec()
> family for that purpose. And if anybody did actually use that
> functionality, they would have complained long ago about it not working.

It doesn't seem like a particularly useful functionality to need to
have, no.  I'd much rather see the other bugs fixed.

Peter Naulls - peter at chocky.org        | http://www.chocky.org/
RISC OS C Programming                  | http://www.riscos.info/

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