Date: Sun, 18 Jun 1995 11:52:31 -0400 From: dennis@et.htp.com (dennis) To: freebsd-hackers@freebsd.org Subject: Re: Hardware Reboots Message-ID: <199506181552.LAA26999@mail.htp.com>
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Lyndon writes.... >Relay cards are good in some situations, however I think we're >still interested in emulating the behaviour of programs like FDISK >that force a cold start of the system. > >I've stumbled across two systems now that won't handle software >reboots properly. One is an EISA P90 running BSD/OS 1.1, the other >a PCI running FreeBSD 2.0-R. (Actually, make that three. The third >is a PCI P90 based on the Triton chip set.) FreeBSD 2.0 tries unmapping >all the VM page maps. This doesn't work. The reboot code in FreeBSD >2.0.5-R has changed enough that these machines now reboot. I haven't >examined the source yet to see what they are doing differently. > >Regardless, there should be a documented way to achieve a cold >restart via software ala FDISK. In my case, I'm not concerned about >reinitializing the I/O boards - I just want the machine to be able >to reboot after a panic without needing a helping hand. > >Getting back to relays, one place the simple relay card would be >useful would be in situations where we have PC's deployed as >routers in remote locations. I have to wonder if such a product is >worth the cost of obtaining UL and CSA certification for. I can't >see anyone making a lot of money off such a beast. > FDISK does not do a cold restart...it just does more stuff than a pure soft reset. The problem that you are having with your cards cannot be corrected by the soft procedures mentioned. In BSD/OS, there is a driver function which gets called on a shutdown or reboot which the driver should use to reset the card. The problem is typically with shared ram cards...theres an initialization problem with some bios which causes the read to fail if the shared ram card memory is active. If you can disable the ram (a card reset should do this) then the system should reboot properly. I don't believe that FreeBSD has such a function...but its a good idea. Of course this all is based on the assumption that there is someone there to soft reboot, or that you CAN soft reboot. The purpose of a watchdog timer is for those times..... dennis
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