From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gary Thomas To: Doug Fraser Cc: ecos-discuss@sources.redhat.com, fche@redhat.com, Christoph Csebits Subject: RE: [ECOS] Hardware Watchdog Date: Thu, 26 Jul 2001 10:13:00 -0000 Message-id: References: X-SW-Source: 2001-07/msg00835.html On 26-Jul-2001 Doug Fraser wrote: > Interrupts may not be enabled in redboot, but > does that stop him from installing his own > tick handler and servicing the watchdog from there? > The maximum time on the 860 watchdog is around > three seconds with a 50Mhz CPU clock. > As Christoph mentioned, the watchdog activates > a hard reset cycle, and there is nothing you can > do to catch it. The other problem is that if you > disable the watchdog, you cannot reenable it > without performing a hard reset. > So the idea is that you need some piece of code telling the watchdog "I'm alive", correct? Surely this can be done without all of the baggage of handling interrupts. > As well as servicing it with a tick interrupt > during redboot, you could also disable it if > the redboot polling mechanism detects a GDB > connect. You probably want the watchdog off > during debugging anyway, so that would allow the > target to boot with a watchdog in a normal run > state, yet reduce the complexity of having to > service it during a debug session. > I don't see how you can handle interrupts without enabling then. Once they are enabled, then other interrupt conditions might need to be serviced, etc. I think it much better/wiser to figure out where it might be "looping" and put in stuff to tickle the watchdog appropriately.