Date: Mon, 1 Apr 1996 10:40:18 +0930 (CST) From: Michael Smith <msmith@atrad.adelaide.edu.au> To: melrobin@Jetson.UH.EDU (Melvin Deloyd Robinson) Cc: questions@freebsd.org Subject: Re: Rebooting Message-ID: <199604010110.KAA01801@genesis.atrad.adelaide.edu.au> In-Reply-To: <1.5.4b12.32.19960330183753.0068df5c@jetson.uh.edu> from "Melvin Deloyd Robinson" at Mar 30, 96 12:37:53 pm
next in thread | previous in thread | raw e-mail | index | archive | help
Melvin Deloyd Robinson stands accused of saying: > > I have a friend who has installed FreeBSD 2.1-RELEASE on his machine. Upon > rebooting he gets an error stating that the Keyboard reboot failed and then > the machine tries the CPU shutdown. The later never works and I'm stumped > about what to tell him. His motherboard chipset and keyboard controller are bogus. He has no alternative but to use the Reset button, as it's impossible to cause his machine to reboot in the "normal" fashions. > I looked in the code (module vm_machdep.c) and found the error message, but > can't glean very much from that. Looking at the dmesg output the sc0 driver > is from 60h-6Fh which seems correct (at least it agrees with my machine), > but is this the address for IO_KBD. The code outputs 0xFE to IO_KBD + 4, > but is this the same as CTRL-ALT-DELETE? The 'vulcan nerve pinch' isn't special - under DOS it's interpreted by the BIOS which causes a reboot, under FreeBSD it's handled by the keyboard driver. The command to the keyboard controller is supposed to strobe the CPU reset line - if the 'Keyboard reset failed' message shows, this has failed to happen. The shutdown code then tries to generate a triple fault, which should cause the CPU to reset, but this fails also on some motherboards. (Your friend quite likely has a UMC chipset on their motherboard). There's an option "BROKEN_KEYBOARD_RESET" that avoids using the keyboard reset technique because it causes some motherboards to hang, and thus the triple-fault technique never gets tried. In your friend's case, there is most likely nothing that can be done. > Melvin -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199604010110.KAA01801>