Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755165AbcLQK5c (ORCPT ); Sat, 17 Dec 2016 05:57:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38882 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753776AbcLQK5a (ORCPT ); Sat, 17 Dec 2016 05:57:30 -0500 Date: Sat, 17 Dec 2016 18:57:21 +0800 From: Dave Young To: Jean Delvare Cc: Andy Shevchenko , kexec@lists.infradead.org, Mika Westerberg , Eric Biederman , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, matt@codeblueprint.co.uk, ard.biesheuvel@linaro.org Subject: Re: [PATCH v1 2/2] firmware: dmi_scan: Pass dmi_entry_point to kexec'ed kernel Message-ID: <20161217105721.GB6922@dhcp-128-65.nay.redhat.com> References: <20161202195416.58953-1-andriy.shevchenko@linux.intel.com> <20161202195416.58953-3-andriy.shevchenko@linux.intel.com> <20161215122856.7d24b7a8@endymion> <20161216023213.GA4505@dhcp-128-65.nay.redhat.com> <1481890738.9552.70.camel@linux.intel.com> <20161216143330.69e9c8ee@endymion> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161216143330.69e9c8ee@endymion> User-Agent: Mutt/1.7.1 (2016-10-04) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Sat, 17 Dec 2016 10:57:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1263 Lines: 36 Ccing efi people. On 12/16/16 at 02:33pm, Jean Delvare wrote: > On Fri, 16 Dec 2016 14:18:58 +0200, Andy Shevchenko wrote: > > On Fri, 2016-12-16 at 10:32 +0800, Dave Young wrote: > > > On 12/15/16 at 12:28pm, Jean Delvare wrote: > > > > I am no kexec expert but this confuses me. Shouldn't the second > > > > kernel have access to the EFI systab as the first kernel does? It > > > > includes many more pointers than just ACPI and DMI tables, and it > > > > would seem inconvenient to have to pass all these addresses > > > > individually explicitly. > > > > > > Yes, in modern linux kernel, kexec has the support for EFI, I think it > > > should work naturally at least in x86_64. > > > > Thanks for this good news! > > > > Unfortunately Intel Galileo is 32-bit platform. > > If it was done for X86_64 then maybe it can be generalized to X86? For X86_64, we have a new way for efi runtime memmory mapping, in i386 code it still use old ioremap way. It is impossible to use same way as the X86_64 since the virtual address space is limited. But maybe for 32bit, kexec kernel can run in physical mode, but I'm not sure, I would suggest Andy to do a test first with efi=noruntime for kexec 2nd kernel. Thanks Dave > > -- > Jean Delvare > SUSE L3 Support