Subject: Re: Intel 82371 power management controller
To: Nathan J. Williams <>
From: Steven M. Bellovin <>
List: netbsd-users
Date: 09/25/2002 16:06:48
In message <>, "Nathan J. Willia
ms" writes:
>Steve Bellovin <> writes:
>> One of my machines shows the following message at boot time:
>> Intel 82371AB Power Management Controller (PIIX4) (miscellaneous bridge, rev
>ision 0x01) at pci0 dev 7 function 3 not configured
>> I *assume* that that's the device that permits things like 'halt -p' to 
>> actually power down the machine.  Is there any support for it?
>This isn't quite how it works. We don't support talking to that (or
>other PMC's) directly, but the APM BIOS routines run interference
>between it and the kernel, so we don't need direct support in order to
>do things like sleep and suspend a system. The lack of an attachment
>for it isn't a problem.

>I would just give the APM commands a try and see if they work - they
>probably do.

They don't, which is what led me down this path...  Nor does apm0 
appear in the dmesg output, and it is configured in the running kernel.  
I'd better check to see if there are any relevant BIOS options.  
(Aside:  this is a desktop, for which the need for 'suspend' is 
minimal.  But I'm planning on hooking it to a UPS, and I'd like 
to be able to power down the machine completely if necessary.)

		--Steve Bellovin, (me) ("Firewalls" book)