From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VokHd-0002cS-5u for kexec@lists.infradead.org; Fri, 06 Dec 2013 01:32:46 +0000 Date: Fri, 6 Dec 2013 09:31:44 +0800 From: Dave Young Subject: Re: [PATCH v4 07/12] efi: passing kexec necessary efi data via setup_data Message-ID: <20131206013143.GA3792@dhcp-16-126.nay.redhat.com> References: <1386023600.1791.201.camel@misato.fc.hp.com> <1386034289.1791.210.camel@misato.fc.hp.com> <20131203015613.GB3980@dhcp-16-126.nay.redhat.com> <1386085140.1791.218.camel@misato.fc.hp.com> <20131204024610.GA3764@dhcp-16-126.nay.redhat.com> <1386175428.1791.225.camel@misato.fc.hp.com> <20131205015615.GC3736@dhcp-16-126.nay.redhat.com> <20131205115124.GC14407@pd.tnic> <1386258962.1791.268.camel@misato.fc.hp.com> <20131205205250.GF14407@pd.tnic> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20131205205250.GF14407@pd.tnic> 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: Borislav Petkov Cc: mjg59@srcf.ucam.org, linux-efi@vger.kernel.org, Toshi Kani , matt@console-pimps.org, greg@kroah.com, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, James.Bottomley@HansenPartnership.com, horms@verge.net.au, ebiederm@xmission.com, hpa@zytor.com, vgoyal@redhat.com On 12/05/13 at 09:52pm, Borislav Petkov wrote: > On Thu, Dec 05, 2013 at 08:56:02AM -0700, Toshi Kani wrote: > > The smbios in efi_setup_data is necessary for kexec to pass the physical > > address of the SMBIOS table from the 1st kernel to the 2nd kernel. > > > > The kernel boot sequence proceeds in the following order. Step 2 > > requires efi.smbios to be the physical address. However, Dave found > > that EFI system table has a virtual address of SMBIOS in step 1. Hence, > > he sets it back to the physical address with the smbios in > > efi_setup_data. (When it is still the physical address, it simply sets > > the same value.) > > > > 1. efi_init() - Set efi.smbios from EFI system table > > 2. dmi_scan_machine() - Temporary map efi.smbios to access SMBIOS table > > 3. efi_enter_virtual_mode() - Map EFI ranges > > Thanks Toshi, it is all clear now. > > @Dave: you might want to put Toshi's explanation in the commit message > of your patch so that we know *why* the change is needed. Ok, will do. Thanks Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec