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Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!swrinde!sdd.hp.com!nigel.msen.com!yale.edu!ira.uka.de!Germany.EU.net!hcshh!hm From: hm@hcshh.hcs.de (Hellmuth Michaelis) Newsgroups: comp.os.386bsd.development Subject: Powerfail / UPS implementation Keywords: ups powerfail device driver init Message-ID: <2107@hcshh.hcs.de> Date: 5 Apr 93 18:25:48 GMT Organization: HCS GmbH, Hamburg, Europe Lines: 41 One of the machines nearby has a uninterruptable power supply built in and i would like to have it activated. So what is the best (most generic) way of implementing it into 386BSD ? What i have in mind is: - a device driver capable of reporting the status of the power supply (running from AC / running from DC). Should the query be implemented as a read() returning a char or as a ioctl() ? - a daemon starting at /etc/rc.local and running in the background asking every minute or so for the power supply status by using the device driver above. - on AC power failure the daemon sends SIGPWR to init, causing it to go to single user mode (powerfail mode ?). - now init has to monitor the power supply, if the AC power comes back again. if AC comes back again, init takes the system back to multiuser mode, else the batteries get empty, then after AC power comes back, init reboots as usual. The only hardware dependent part would be the device driver, but since the output is binary (power good/bad) the driver should be simple to adapt to common ups-monitoring devices. Since the only (PC-based) ups-device i have ever seen is mine (built in), is the above draft sufficient as a general purpose solution ? Does another solution already exist for 386BSD ? Any comments ? hellmuth -- hellmuth michaelis HCS Hanseatischer Computerservice GmbH hamburg, europe hm@hcshh.hcs.de tel: +49/40/55903-170 fax: +49/40/5591486 [ the opinions expressed above are my own and not the opinion of anybody else ]