roode%uci-750a@BRL-VGR.ARPA (01/06/84)
From: Dana Roode <roode%uci-750a@BRL-VGR.ARPA> We are experiencing mysterious halts on our 750 system, which, if we had not just installed 4.2BSD and not had the problem before, we would swear were hardware caused. The system will be running fine, and out of nowhere, we halt: 800202CA 04 The documentation says the "04" halt code indicates "interrupt stack not valid or unable to read SCB". The address corresponds to "_dumpsys+.9e" in our kernel, which appears to be a harmless "pushaf" of an argument for printf. Of course the fact that we are in "dumpsys" probably indicates we were trying to crash anyway, but why, I don't know. Nothing appears on the console before the halt, and the system does not try to continue despite the fact that the console switch is in its normal "restart" position. After some of these crashes, we were unable to reboot at all without powering the CPU on and off. We would type the boot command to the front end and receive a micro verify check failure (single "%" or "%O"). This lead us to believe we had a hardware problem. DEC replaced our L0002 CPU module, which they said included the microcode hardware involved. We have had another abrupt halt since then, but this time the system responded properly to a boot command. Has anyone seen a problem like this one with 4.2? (or 4.1?) Hardware or software? If there was an original problem that triggered entry into the dumpsys routine, how do we find what the problem was, given that nothing is printing on the console? Since we are in great need to get our system back on its feet as soon as possible, please send a copy of all replies directly to me. Thanks, Dana Roode University of California, Irvine roode.uci@rand-relay -or- ucbvax!ucivax!roode