2009-12-01 15:09:12     Watchdog timer, reboot question

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2009-12-01 15:09:12     Watchdog timer, reboot question

Tim Shearer (UNITED STATES)

Message: 82926   

 

I'm trying to find out if the watchdog peripheral is disabled after a soft reset is actioned.  This is because I don't wish to use the safe-exit watchdogd mode in case there is a panic during reboot.

 

According to the docs and HRM, the "raise 1" instruction causes a core-only reset that touches no peripherals, so it's left to u-boot to disable the watchdog.  However, CONFIG_HW_WATCHDOG isn't defined in my u-boot configuration, so the watchdog doesn't appear to be disabled by the bootloader either.

 

So how come the watchdog isn't resetting the processor after a rebooting into the u-boot prompt where it sits idling?  (BTW I've tested it works in Linux with the crash-test utility.)

 

Thanks in advance!

 

Tim

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2009-12-01 15:16:32     Re: Watchdog timer, reboot question

Tim Shearer (UNITED STATES)

Message: 82927   

 

...oh and I'm aware this might belong in the u-boot forum, depending on the answer!

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2009-12-01 15:32:27     Re: Watchdog timer, reboot question

Mike Frysinger (UNITED STATES)

Message: 82929   

 

the kernel doesnt do a core-reset only as it doesnt make any sense.  when you type 'reboot' under linux, both the system and core are reset, thus the watchdog is disabled.

 

u-boot assumes a system-reset state.

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2009-12-01 15:37:08     Re: Watchdog timer, reboot question

Tim Shearer (UNITED STATES)

Message: 82930   

 

Many thanks Mike.

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