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Re: watchdog - powerpc


Bob Koninckx wrote:
Powerpc _enables_ the watchdog by default. According to the hardware
manual you can only disable it out of reset but never re-enable it
afterwards.

from the spec ... SYPCR

This register can be read at any time but can be written only once after
system reset ...

I do not think you want a watchdog in redboot. But then redboot needs to
disable it, meaning you can not use it in the application afterwards
either. On the other hand, leaving it enabled in redboot gives the
application a chance to decide. But then you'll end up having problems
in redboot if you do not start the application fast enough. Am I missing
something ?

Have the HAL provide a default NO-OP watchdog exception handler that acks the watchdog (or whatever's required)? An application or watchdog device driver can then override as required just by overriding the exception.


Or arguably just write a standard watchdog device driver (as lives in devs/watchdog and uses io/watchdog) and include it in the RedBoot image.... and if CYGPKG_IO_WATCHDOG isn't defined in <pkgconf/system.h> just disable the watchdog entirely in SYPCR.

Jifl
--
eCosCentric    http://www.eCosCentric.com/    The eCos and RedBoot experts
--[ "You can complain because roses have thorns, or you ]--
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