Re: restart after power outage

["Jonathan A. Kollasch" <jakllsch%kollasch.net@localhost>]

On Mon, Oct 21, 2019 at 02:04:22PM +0000, Steve Blinkhorn wrote:
> We had a power outage last night, which is a very rare event
> hereabouts.  All our machines restarted normally when power was
> restored, Internet connection and WiFi the same, but for one utility
> machine which provides mail and name service.  Looking at the lack of
> entries in /var/log/messages, and the identical NetBSD configuration
> on other machines, it seems to me that there must be an incorrect BIOS
> setting.  
> 
> Because this is a headless server with no out-of-band remote console,
> and because of the physical disposition of equipment and how the
> screen and keyboard are connected, it is not a simple matter matter to
> get to the BIOS in the ordinary way.
> 
> Is there a way of reading (or even better writing) the CMOS settings
> from within NetBSD?

Assuming you can find the relevant CMOS NVRAM bit, you can use
nvramtool in pkgsrc to read/write the contents of the NVRAM.

That said, without a coreboot option table, finding the bit will
probably require you to use the firmware configuration setup utility to
turn the knob and then see what changed.  At which point your problem
will have been solved already..

Additionally, the standby power well register that is the actual knob
that controls power state after power loss is system specific, so
finding it will require detailed knowledge of the hardware in the
system.  That said, if found, it could be adjusted independently of the
NVRAM.

Additionally, more modern systems may store preferences in the boot
Flash ROM, so the preference bit may not even exist in the CMOS NVRAM.

	Jonathan