Re: G5 powermacs

[Michael <macallan%netbsd.org@localhost>]

On Sat, 10 Jun 2017 19:59:43 +0200 (CEST)
Havard Eidnes <he%NetBSD.org@localhost> wrote:

> > The SMU ( and most PMUs ) has a timer, if it isn't told that the OS is
> > up <timeout> after powering up ( or attempting to boot ) it will assume
> > we crashed and as a safety measure crank up the fans.  
> 
> Right, so it also depends on the OS periodically polling the
> status.  It wasn't entirely clear to me whether there's a kernel
> thread which takes the responsibility for polling, or whether
> it's relegated to user-land (which isn't up at this point).

I'm not sure if the SMU needs to be polled like a watchdog, PMUs
certainly don't ( but they work in rather different ways, so who knows
). Would explain why fans speed up when OSX crashes. So, if it's there
it's probably in the smu driver.

have fun
Michael