From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jack Steiner Date: Tue, 13 Jul 2004 14:54:13 +0000 Subject: Re: fix memory corruption/crash for physical-mode EFI calls Message-Id: <20040713145413.GA25989@sgi.com> List-Id: References: <16623.29412.381259.793452@napali.hpl.hp.com> In-Reply-To: <16623.29412.381259.793452@napali.hpl.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Fri, Jul 09, 2004 at 09:39:00PM -0700, David Mosberger wrote: > Jesse, > > I think you'll want to try out the patch below. If my guess is > correct and the SGI firmware doesn't support switching into virtual > mode, then this may fix the boot-problem you are seeing on SN2. FYI, I looked at the SGI boot failures that are occurring on recent 2.6 kernels that have INIT_TASK in region 5. The boot failures are caused by a bug in our PROM. It incorrectly assumes that the stack is identity mapped. (Dont ask... :-) Moving the stack to region 5 causes an OOPs in some PAL calls. It goes downhill from there - sending signals to processes early in boot before kmem is initialized doesnt get very far. The result is an MCA that has nothing to do with the original failure but adds a lot of confusion. We'll fix our PROM.... -- Thanks Jack Steiner (steiner@sgi.com) 651-683-5302 Principal Engineer SGI - Silicon Graphics, Inc.