From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262610AbVHDS4k (ORCPT ); Thu, 4 Aug 2005 14:56:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262613AbVHDS4k (ORCPT ); Thu, 4 Aug 2005 14:56:40 -0400 Received: from ns2.suse.de ([195.135.220.15]:61611 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S262610AbVHDS4i (ORCPT ); Thu, 4 Aug 2005 14:56:38 -0400 Date: Thu, 4 Aug 2005 20:56:32 +0200 From: Andi Kleen To: Tom Rini Cc: Andi Kleen , akpm@osdl.org, linux-kernel@vger.kernel.org, amitkale@linsyssoft.com Subject: Re: [patch 07/15] Basic x86_64 support Message-ID: <20050804185632.GD8266@wotan.suse.de> References: <1.2972005.trini@kernel.crashing.org> <20050803130531.GR10895@wotan.suse.de> <20050803133756.GA3337@smtp.west.cox.net> <20050804123900.GR8266@wotan.suse.de> <20050804140445.GB3337@smtp.west.cox.net> <20050804140620.GW8266@wotan.suse.de> <20050804141437.GC3337@smtp.west.cox.net> <20050804142806.GX8266@wotan.suse.de> <20050804150636.GD3337@smtp.west.cox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050804150636.GD3337@smtp.west.cox.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 04, 2005 at 08:06:36AM -0700, Tom Rini wrote: > > > > Why can't you run on x86-64 early? > > As I said earlier: > " > > If you want to run gdb earlier you need to do it without a tasklet. > > We really would like to try again once stacks are setup (IOW, once > if ((&__get_cpu_var(init_tss))[0].ist[0])) is true). > " > > IOW, when we parse the params on x86_64 this isn't true (or rather it > wasn't true as of 2.6.9'ish, if this has changed I'd be glad to retest > things). The ISTs are set up for the boot processor extremly early - even before start_kernel. But they are useless before trap_init() runs because you won't get any exceptions that need an IDT (or rather they will all still point to the early exception handler that just panics) -Andi