Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750998AbWCGNkk (ORCPT ); Tue, 7 Mar 2006 08:40:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750988AbWCGNkk (ORCPT ); Tue, 7 Mar 2006 08:40:40 -0500 Received: from mail.suse.de ([195.135.220.2]:7314 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1750729AbWCGNkj (ORCPT ); Tue, 7 Mar 2006 08:40:39 -0500 Message-ID: <440D8D97.6000300@suse.de> Date: Tue, 07 Mar 2006 14:41:43 +0100 From: Gerd Hoffmann User-Agent: Thunderbird 1.5 (X11/20060111) MIME-Version: 1.0 To: "Eric W. Biederman" Cc: linux kernel mailing list Subject: Re: [PATCH] Fix ELF entry point (i386) References: <43FC4682.6050803@suse.de> <440C363F.8000503@suse.de> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1402 Lines: 33 > Currently my assumptions are: > > Standalone executables load at the physical not the virtual addresses. > Standalone executables start executing at a physical address and not at > a virtual address. Well, that is true for real hardware. xen guest kernels are booted with paging already enabled and thus the entry point is in virtual memory, and I'm trying to figure how to handle that best (both for initial boot and kexec). xen uses a special xen header anyway to give the domain builder a hint how the initial page tables should look like (they look simliar to what head.S creates on real hardware). That can also be used to figure the correct virtual entry point from the physical one. It probably even makes more sense to do that (instead of writing the virtual address into the entry point) as the xen domain builder doesn't look at the virtual addresses in the ELF headers too. It uses PAGE_OFFSET+paddr instead. That keeps the differences between real and virtual hardware small ... cheers, Gerd -- Gerd 'just married' Hoffmann I'm the hacker formerly known as Gerd Knorr. http://www.suse.de/~kraxel/just-married.jpeg - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/