pmac_halt() bug

Baevsky, Igal igal.baevsky at
Tue Nov 11 23:03:32 EST 2003

When in MacOS I can just unplug the power cable and put it back and the
system will power on. On linux it's not working - after power cable is back,
the system is not powering on.
After playing with /etc/init.d/halt script I managed to bring system to the
state where all processes are stoped and all FS are unmounted but the system
is still up.
As I understand, I need some module or tool to write something to the MAC
bios or eeprom whatever, during linux startup. Can somebody tell me what can
I use ?

-----Original Message-----
From: Benjamin Herrenschmidt [mailto:benh at]
Sent: Tue, November 11, 2003 10:25
Subject: Re: pmac_halt() bug

> That's precisely it. Some (all?) pmacs with server mode don't
> automatically turn on after an intentional shutdown, only after power
> is lost. So the idea is to have the UPS signal the computer to halt,
> and then have the UPS cut power once it's safe. Later the UPS switches
> power back on and the computer will automatically boot.

Ok, 2 things:

- How does the UPS knows it's "safe" ?
- And right, I need to disable server mode to be able to shut down :) So
I indeed to that on those machines

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