--- In gbadev@yahoogroups.com, Jason Wilkins <fenix@i...> wrote:
> It turns out that [Pokemon Sapphire's ISR] looks almost exactly
> like the multiple interrupts routine with user stack switching and
> cart interrupt handling that is in Jeff's crtls.
>
> So, I checked Super Mario Advance. Same code (except the
> priorities). Now I'm starting to worry. People are so nervous
> about including Nintendo's logo data

And I keep reassuring them that after Sega v. Accolade,
people who include logo data have nothing to worry about.

> but disassembling code and distributing it is apparently just fine.

If there's only one efficient way to express a given idea, then by
the "merger doctrine", the expression is not worthy of copyright.
I'm guessing that the way Jeff's crt0 and Nintendo's libraries
handle interrupts is relatively commonplace on embedded systems.

> Interesting things to note. I cannot find evidence that either
> game copies its ISR to ram, yet they both attempt to handle the
> cart interrupt by going into an infinite loop. This won't happen
> because the cart will be gone.

Is there a way for a GBA cart to generate an interrupt other than
by being pulled off the bus entirely? For example, NES carts
generated interrupts for all sorts of reasons.

--
Damian