Non Maskable Interrupt in 4.25

QNX Newsgroups (Archives) qdn.public.qnx4
1

How does QNX 4.25 handle NMI? Does it freeze the CPU?

I am probably facing a power feeding problem, and I see my PC board
(running QNX 4.25) crashing without any trace or syslog message (PC is
running without any screen attached).

Thanks in advance for your answers

–
/------------------------------------------------------------

  • Davide Ancri - Prisma Engineering
  • email = davidea AT prisma DASH eng DOT it
    ------------------------------------------------------------/
2

Davide <doesnot@exist.spam> wrote:

How does QNX 4.25 handle NMI? Does it freeze the CPU?

Don’t remember anymore…been too long, but I think you just
die.

I am probably facing a power feeding problem, and I see my PC board
(running QNX 4.25) crashing without any trace or syslog message (PC is
running without any screen attached).

Hm… do you have a (spare) serial port connected? You can re-direct
Proc32’s output to a serial port with the -o option (though you’d better
make sure Dev.ser isn’t also trying to deal with the same serial port).

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.

3

David Gibbs <dagibbs@qnx.com> wrote in message
news:b4ajrm$5qi$1@nntp.qnx.com…

Davide <> doesnot@exist.spam> > wrote:
How does QNX 4.25 handle NMI? Does it freeze the CPU?

Don’t remember anymore…been too long, but I think you just
die.

SIGBUS by default. There is code in /usr/free IIRC that shows how you can
attempt to handle an NMI (I don’t have the location on me at the moment).

Hm… do you have a (spare) serial port connected? You can re-direct
Proc32’s output to a serial port with the -o option (though you’d better
make sure Dev.ser isn’t also trying to deal with the same serial port).

Good idea (in fact if you’re brave you can use the Debugger as well in this
manner). That said, when you have power issues, lots of bizzare things
happen.

-Adam

4

Adam Mallory <amallory@qnx.com> wrote:

David Gibbs <> dagibbs@qnx.com> > wrote in message
news:b4ajrm$5qi$> 1@nntp.qnx.com> …
Davide <> doesnot@exist.spam> > wrote:
How does QNX 4.25 handle NMI? Does it freeze the CPU?

Don’t remember anymore…been too long, but I think you just
die.

SIGBUS by default. There is code in /usr/free IIRC that shows how you can
attempt to handle an NMI (I don’t have the location on me at the moment).

Right…I knew I’d seen something on this, looked in my local archives for
it, but couldn’t find it.

Try:

ftp.qnx.com:/usr/free/qnx4/os/samples/misc/nmi-example.tgz

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.