From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752044Ab2LVCmq (ORCPT ); Fri, 21 Dec 2012 21:42:46 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:44869 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751352Ab2LVCmo convert rfc822-to-8bit (ORCPT ); Fri, 21 Dec 2012 21:42:44 -0500 Date: Fri, 21 Dec 2012 21:42:25 -0500 From: Konrad Rzeszutek Wilk To: Yinghai Lu Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Eric W. Biederman" , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 00/27] x86, boot, 64bit: Add support for loading ramdisk and bzImage above 4G Message-ID: <20121222024225.GG3468@phenom.dumpdata.com> References: <1355814959-10573-1-git-send-email-yinghai@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <1355814959-10573-1-git-send-email-yinghai@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 17, 2012 at 11:15:32PM -0800, Yinghai Lu wrote: > Now we have limit kdump reseved under 896M, because kexec has the limitation. > and also bzImage need to stay under 4g. > > To make kexec/kdump could use range above 4g, we need to make bzImage and > ramdisk could be loaded above 4g. > During booting bzImage will be unpacked on same postion and stay high. > > The patches add fields in setup_header and boot_params to > 1. get info about ramdisk position info above 4g from bootloader/kexec > 2. get info about cmd_line_ptr info above 4g from bootloader/kexec > 3. set xloadflags bit0 in header for bzImage and bootloader/kexec load > could check that to decide if it could to put bzImage high. > 4. use sentinel to make sure ext_* fields in boot_params could be used. > > This patches is tested with kexec tools with local changes and they are sent > to kexec list later. > > could be found at: > > git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git for-x86-boot Did a light test and it looks to work under Xen - thought I had not tested any various configuration of memory layouts. More worryingly it blew up under native under an Dell T105 AMD box with 4GB of memory. I can't get it even to print anything on the serial log: (this is an excerpt from pxelinux.cfg/C0A8 file) LABEL BAREMETAL KERNEL vmlinuz APPEND initrd=initramfs.cpio.gz debug selinux=0 loglevel=10 apic=debug console=uart8250,115200n8 PXELINUX 3.82 2009-06-09 Copyright (C) 1994-2009 H. Peter Anvin et al Loading vmlinuz....................................................................... Loading initramfs.cpio.gz.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ready.