What is a "watchdog reset"?
Having a watchdog on an embedded system will dramatically improve the availability of the device. Instead of waiting for the user to see that the device is frozen or broken, it will reset if the software fails to update at some interval. Some examples:
- Linux System http://linux.die.net/man/8/watchdog
- VxWorks (RTOS) http://fixunix.com/vxworks/48664-about-vxworks-watchdog.html
- QNX Watchdog http://www.qnx.com/solutions/industries/netcom/ha.html
The device is designed in such a way that its state is saved somewhere periodically(like Juniper routers that run FreeBSD, Android phones, and dvrs that run linux). So even if it is rebooted it should re-enter a working configuration.
Bryan Agee
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Updated on September 18, 2022Comments
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Bryan Agee almost 2 years
After reading this question, I was a little confused; it sounds like some daemon reacting by rebooting a system. Is that right? Is it a common occurrence in embedded *nixes?
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Gilles 'SO- stop being evil' almost 13 yearsNot just embedded, also servers (most server motherboards, and some high-end PC motherboards, have this feature). See Watchdog timer on Wikipedia.
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