on 30/11/2008 22:14 Julian Stacey said the following: > Gary Jennejohn wrote: >> On Fri, 28 Nov 2008 15:28:35 +0200 >> Andriy Gapon <[EMAIL PROTECTED]> wrote: >> >>> I have a new machine with DG33TL mainboard (ICH9/G33). >>> In a course of some hacking I ran dd if=/dev/mem ... to scan all memory, >>> this caused the machine to hang. >>> I tried to reproduce and this is 100% reproducible. >>> >>> I am not used to such behavior. In older days I could scan all the >>> memory without any issues. >>> >>> Could this be related to some modern form of memory-mapped IO? Or to >>> Intel Management Engine (that seems t bite into DRAM)? >>> Or something else? >>> >>> Just wondering. >>> >> That's what I would assume. With some hardware just reading a register >> can be harmful. > > I just crashed 3 normally stable machines trying that. > I only tried for casual interest. I acknowledge Gary's comment above :-) > > dd if=/dev/mem of=/dev/null > > FreeBSD lapa.js.berklix.net 4.11-RELEASE FreeBSD 4.11-RELEASE > #0: Fri Jul 7 17:56:30 CEST 2006 > [EMAIL PROTECTED]:/usr/src/sys/compile/LAPA.small i386 > > FreeBSD laps.js.berklix.net 7.0-RELEASE FreeBSD 7.0-RELEASE > #2: Mon Sep 8 15:39:53 CEST 2008 > [EMAIL > PROTECTED]:/usr1/ftp/pri/FreeBSD/releases/7.0-RELEASE/src/sys/i386/compile/LAPS.small > i386 > > FreeBSD john.js.berklix.net 7.1-BETA2 FreeBSD 7.1-BETA2 #0: > Sun Oct 12 20:59:28 UTC 2008 > [EMAIL PROTECTED]:/usr/obj/usr/src/sys/GENERIC amd64
Thank you for going to all the trouble. I see now that I have to be more careful in this respect. -- Andriy Gapon _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
