From owner-freebsd-current Thu Jun 17 13: 9:20 1999 Delivered-To: freebsd-current@freebsd.org Received: from par28.ma.ikos.com (par28.ma.ikos.com [137.103.105.228]) by hub.freebsd.org (Postfix) with ESMTP id E8AE8155AB for ; Thu, 17 Jun 1999 13:09:11 -0700 (PDT) (envelope-from tich@par28.ma.ikos.com) Received: from [[UNIX: localhost]] ([[UNIX: localhost]]) by par28.ma.ikos.com (8.8.7/8.8.7) id QAA14119; Thu, 17 Jun 1999 16:08:44 -0400 From: Richard Cownie To: dg@root.com, David Greenman Subject: Re: 4GB dram Date: Thu, 17 Jun 1999 15:55:11 -0400 X-Mailer: KMail [version 1.1.0] Content-Type: text/plain Cc: freebsd-current@FreeBSD.ORG References: <199906171924.MAA09038@implode.root.com> MIME-Version: 1.0 Message-Id: <99061716084400.14101@par28.ma.ikos.com> Content-Transfer-Encoding: 8bit X-KMail-Mark: Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, 17 Jun 1999, David Greenman wrote: > >I still can't get a machine with 4GB dram to work. When was the last > >time anyone succeeded in running -CURRENT on a machine with 4GB dram ? > >This was working for me with 19990421-CURRENT, it doesn't work in > >19990604-CURRENT. Since support for 4GB dram is the only reason > >I'm running -CURRENT rather than -STABLE, I would really like to know > >when this might get fixed. > > You need to provide more information - specifically, what happens when you > try? > > -DG boot: kernel.4G -v Too many holes in the physical address space, giving up Copyright (c) .... Copyright (c) .... Fatal trap 12: page fault while in kernel mode ... As I've noted earlier, the getmemsize() code doesn't appear very safe w.r.t. 4GB limits. I tried rewriting to simplify this code and avoid these problems - with the rewritten version I got further, but then had a different crash later (but that could be due to a bug in my rewrite). It's desperately painful to debug this, because as far as I know the only way to get any kernel to boot is to power down the machine, physically unplug one of the dimms, power up again, install new kernel, power down, plug the dimm back in ... If I could fit the kernel on a floppy the debugging cycle would be much quicker, but it seems too big for that. Since the debugging is so painful, I would really like to find the latest version that worked with 4GB, so that I can eyeball a minimal set of source code changes. Richard Cownie (tich@ma.ikos.com) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message