Waking XO-1.75 with RTC

James Cameron quozl at laptop.org
Mon Jul 16 08:07:12 EDT 2012

On Mon, Jul 16, 2012 at 06:34:30AM -0400, Paul Fox wrote:
> james wrote:
>  > George Hunt wrote (on power at lists.laptop.org):
>  > > Does anyone have experience waking up an XO via the RTC?  Manual
>  > > entries for rtcwake make it sound pretty easy. But there's no real
>  > > substitute for experience.
>  > 
>  > rtcwake with a delta time works for me on XO-1.75, you can see a
>  > rather technical example in /runin/runin-sus, but it boils down to
>  > 
>  > 	sudo rtcwake --seconds 60 --mode mem
>  > 
>  > I'm not sure if it works with an absolute time ... I doubt it, but
>  > I've not had a moment to try it.  We don't have a need for absolute
>  > time wakeup in the OLPC OS builds.
> i'm not sure i've tried an absolute wakeup time either, but i know
> of no reason it shouldn't just work.

the reason i suspect it won't do what is desired is that the internal
RTC is not set, and holds a time since boot instead of anything close
to wall clock time.

i guess it may work fine if the absolute wakeup time is specified in
time since boot.

James Cameron

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