From owner-freebsd-questions Tue Mar 7 09:05:06 1995 Return-Path: questions-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id JAA18656 for questions-outgoing; Tue, 7 Mar 1995 09:05:06 -0800 Received: from cs.weber.edu (cs.weber.edu [137.190.16.16]) by freefall.cdrom.com (8.6.10/8.6.6) with SMTP id JAA18649 for ; Tue, 7 Mar 1995 09:05:05 -0800 Received: by cs.weber.edu (4.1/SMI-4.1.1) id AA24832; Tue, 7 Mar 95 09:57:19 MST From: terry@cs.weber.edu (Terry Lambert) Message-Id: <9503071657.AA24832@cs.weber.edu> Subject: Re: System hangs when changing root device To: jmrueda@diatel.upm.es (Javier Martin Rueda) Date: Tue, 7 Mar 95 9:57:19 MST Cc: questions@FreeBSD.org In-Reply-To: <629*/S=jmrueda/OU=diatel/O=upm/PRMD=iris/ADMD=mensatex/C=es/@MHS> from "Javier Martin Rueda" at Mar 7, 95 01:15:20 pm X-Mailer: ELM [version 2.4dev PL52] Sender: questions-owner@FreeBSD.org Precedence: bulk > > I created a boot disk with rawrite (using the "newer" bootdisk from FreeBSD > > 2.0-RELEASE) and everything was probed OK, but after the message "changing > > root device to fd0c" appeared, the computer freezed. > > This is just to say that I changed the motherboard from a PCI+VESA with UMC > chipset to a PCI+VESA with Opti chipset, and things started to work. > > However, then the network card (SMC EtherPower 8432BT PCI) did not work. > This was solved by changing the IRQ from 9 to 11. The computer also has > a serial port in IRQ2, and that must be conflicting with IRQ9. > > Maybe the problem with the old motherboard was also due to some IRQ > conflict, although everything seemed to be probed OK. I must say that I > have a VESA motherboard with UMC chipset at home and it works fine with > FreeBSD 2.0R. There are/were known cache writeback problems with the UMC chipset. In theory, these are repairable using CMOS settings. I believe the interesting setting had to do with write-through vs. write-back. I thought this had been fixed in software and foolishly discarded the information (well, put it on tape some place -- I never delete anything I once found interesting, really). If you could try this with your board and, if it fixed the problem, document it for others, you would be well loved. Terry Lambert terry@cs.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.