From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262593AbVHDTIu (ORCPT ); Thu, 4 Aug 2005 15:08:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262613AbVHDTIt (ORCPT ); Thu, 4 Aug 2005 15:08:49 -0400 Received: from fed1rmmtao10.cox.net ([68.230.241.29]:43701 "EHLO fed1rmmtao10.cox.net") by vger.kernel.org with ESMTP id S262593AbVHDTIt (ORCPT ); Thu, 4 Aug 2005 15:08:49 -0400 Date: Thu, 4 Aug 2005 12:08:47 -0700 From: Tom Rini To: Andi Kleen Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, amitkale@linsyssoft.com Subject: Re: [patch 07/15] Basic x86_64 support Message-ID: <20050804190847.GF3337@smtp.west.cox.net> References: <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> <20050804185632.GD8266@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050804185632.GD8266@wotan.suse.de> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 04, 2005 at 08:56:32PM +0200, Andi Kleen wrote: > 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) I wonder if there was a reason we couldn't do what we did with i386 and make an early_trap_init() so that we can get what we care about that early at least. I'll have to poke at this a bit more, thanks! -- Tom Rini http://gate.crashing.org/~trini/