From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753372Ab2LFAV5 (ORCPT ); Wed, 5 Dec 2012 19:21:57 -0500 Received: from terminus.zytor.com ([198.137.202.10]:41463 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751930Ab2LFAVz (ORCPT ); Wed, 5 Dec 2012 19:21:55 -0500 Message-ID: <50BFE50C.8030008@zytor.com> Date: Wed, 05 Dec 2012 16:21:32 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Matthew Garrett CC: Yinghai Lu , Bjorn Helgaas , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-efi@vger.kernel.org, mfleming@intel.com, dwmw2@infradead.org, "Eric W. Biederman" Subject: Re: Use PCI ROMs from EFI boot services References: <1345739803-21017-1-git-send-email-mjg@redhat.com> <20121203200241.GG5906@thinkpad-t410> <20121206001819.GA30527@srcf.ucam.org> In-Reply-To: <20121206001819.GA30527@srcf.ucam.org> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/05/2012 04:18 PM, Matthew Garrett wrote: > On Wed, Dec 05, 2012 at 04:15:56PM -0800, Yinghai Lu wrote: > >> at the same time we should export setup_data into /sys, so kexec could >> append this pointer to command of >> second kernel, just like kexec append acpi_rsdp. >> That should address DavidW's concern. > > Why should the kernel export data to userspace just so that that data > can be passed back into the kernel? > Because it also needs to modify it. Right now kexec userspace synthesizes struct boot_params from scratch, and does so incorrectly to boot. I think we have setup_data exported via debugfs but IIRC we never got a strong enough use case for sysfs. -hpa