[ECOS] watchdog - powerpc
Fri May 23 01:55:00 GMT 2003
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
> 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.
eCosCentric http://www.eCosCentric.com/ The eCos and RedBoot experts
--[ "You can complain because roses have thorns, or you ]--
--[ can rejoice because thorns have roses." -Lincoln ]-- Opinions==mine
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