Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754264Ab0FCNa6 (ORCPT ); Thu, 3 Jun 2010 09:30:58 -0400 Received: from cantor.suse.de ([195.135.220.2]:44239 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753824Ab0FCNa5 (ORCPT ); Thu, 3 Jun 2010 09:30:57 -0400 Date: Thu, 3 Jun 2010 15:30:55 +0200 From: Michal Marek To: Sam Ravnborg Cc: Christoph Hellwig , Jaswinder Singh Rajput , Ingo Molnar , Andrew Morton , the arch/x86 maintainers , Linux Kernel Mailing List Subject: Re: config automatically switches from 32-bit to 64-bit for x86 Message-ID: <20100603133055.GA27797@sepie.suse.cz> References: <20100527154916.GA5585@infradead.org> <20100527184653.GA11830@merkur.ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100527184653.GA11830@merkur.ravnborg.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2049 Lines: 50 On Thu, May 27, 2010 at 08:46:53PM +0200, Sam Ravnborg wrote: > On Thu, May 27, 2010 at 11:49:16AM -0400, Christoph Hellwig wrote: > > On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote: > > > Hello, > > > > > > I am trying to build 32 bit kernel image on 64-bit machine but after > > > 'make menuconfig' it automatically switches 32-bit to 64-bit. > > > > > > Is this a BUG or did intentionally. > > > > I think it's intentional, but I'm really annoyed by this behaviour. > > The request when we did the merge of 32 and 64 bit was that we > should continue to build 64bit kernels on 64 bit machines. > And likewise for 32bit. > Because this was what the users where used to. > > We could simplify metters by defining new rules. > As you suggest that uname on an intel box always resulted in ARCH=x86. > But then people would complain why a 32 bit kernel is default when > the box is 64 bit. Which is not acceptable, IMO. An x86_64 distro typically has a complete 64bit userspace including /sbin/init, so the default kernel has to be 64bit. What about always making the prompt visible, so that the previously set value gets reused? The downside is that 'make ARCH=i386 menuconfig' in a clean tree on x86_64 will default to 64bit, because it will find the setting in the config of the running 64bit kernel :(. But after manually turning CONFIG_64BIT off, the setting will be preserved. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index dcb0593..05ec418 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -3,7 +3,7 @@ mainmenu "Linux Kernel Configuration for x86" # Select 32 or 64 bit config 64BIT - bool "64-bit kernel" if ARCH = "x86" + bool "64-bit kernel" default ARCH = "x86_64" ---help--- Say yes to build a 64-bit kernel - formerly known as x86_64 -- 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/