From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from terminus.zytor.com ([2001:1868:205::10] helo=mail.zytor.com) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vjsbg-00017K-W2 for kexec@lists.infradead.org; Fri, 22 Nov 2013 15:25:22 +0000 Message-ID: <528F7735.9010209@zytor.com> Date: Fri, 22 Nov 2013 07:24:37 -0800 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [PATCH 5/6] kexec-bzImage: Support for loading bzImage using 64bit entry References: <1384969851-7251-1-git-send-email-vgoyal@redhat.com> <1384969851-7251-6-git-send-email-vgoyal@redhat.com> <20131121190710.GD17070@kroah.com> <20131121192114.GN16208@redhat.com> In-Reply-To: <20131121192114.GN16208@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Vivek Goyal , Greg KH Cc: mjg59@srcf.ucam.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, ebiederm@xmission.com On 11/21/2013 11:21 AM, Vivek Goyal wrote: >> >> What do you mean by the "real mode entry"? Do we need to care about >> that because we aren't falling back to real mode when executing this, >> are we? Or does that just happen for 32bit kernels? > > Original kexec offers real mode entry choice too. So we fall back > to real mode and jump to kernel and kernel makes bunch of BIOS calls. I > don't think this is a commonly used option. > I know some users of it (who I shall not name.) In general it is a bad option, because after running the first kernel the state of the hardware is not guaranteed to be such that executing the BIOS is safe. In general, I do think they do it just because they tried at some point and it happened to work; discouraging its use is probably for the better. -hpa _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec