Problems with the demo CD and qemu

Cedric Roux Cedric.Roux at
Mon Feb 14 10:40:17 CET 2005

On Sat, 12 Feb 2005, Adam Lackorzynski wrote:

> > My questions are:
> >   1 - why to call this switch_to_irq_idle_loop? what's
> >       the purpose of it?
> The purpose is to prevent that interrupts get through. The tricky part
> here has been IRQ probing. I guess I need to reevaluate this issue...

Yes, the point is that the thread calls switch_to_irq_idle_loop to
disable itself, weird :) (it can't be enabled again, because the
one that would do it is itself, but itself disabled itself, I mean...
weird :))

Maybe you can test this specific case and not call switch_to_irq_idle_loop
when the calling thread is the IRQ one?

> >   2 - if I remove this call, do I get a wrong system or
> >       is it ok? what do I lose if it is ok (speed?)?
> Should be ok if it works on your system.

Mmm, not very satisfaying as an answer :)

> > (By the way, the l4linux kernel won't compile with 4k stacks,
> It compiled for me as of today but I had to fix some small issues to
> make it actually work (but I only tested this slightly). Should hit CVS
> by tomorrow.
> > you never call irq_ctx_init, maybe you should call it in
> > init_IRQ?)
> No, l4linux has always worked more like the 4k-IRQ way, not as the old
> way in 8k-stacks.

OK, I used the wrong word. It compiled, but it didn't work at runtime.

> Adam

Anyway, thanks.

Now, I have some General Protection Faults occuring at l4linux boot time
I don't know where and I don't know why. Is it a known issue?
because I don't have much time to investigate it.
And if it is a known issue, what should I do to fix this?
(otherwise, I'll live with it, trying to get the point when time
will be there)


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