From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [PATCH v4 07/12] efi: passing kexec necessary efi data via setup_data Date: Thu, 5 Dec 2013 21:52:50 +0100 Message-ID: <20131205205250.GF14407@pd.tnic> References: <20131129091415.GH4186@dhcp-16-126.nay.redhat.com> <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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <1386258962.1791.268.camel-RbGIw1UOYPVo/CpIj0byZw@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Toshi Kani , Dave Young Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org, hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, James.Bottomley-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, horms-/R6kz+dDXgpPR4JQBCEnsQ@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org, matt-HNK1S37rvNbeXh+fF434Mdi2O/JbrIOy@public.gmane.org List-Id: linux-efi@vger.kernel.org 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. Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --