From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 11 Jun 2013 17:42:56 +0200 (CEST) Received: from localhost.localdomain ([127.0.0.1]:49214 "EHLO linux-mips.org" rhost-flags-OK-OK-OK-FAIL) by eddie.linux-mips.org with ESMTP id S6835172Ab3FKPlkp-52l (ORCPT ); Tue, 11 Jun 2013 17:41:40 +0200 Received: from scotty.linux-mips.net (localhost.localdomain [127.0.0.1]) by scotty.linux-mips.net (8.14.5/8.14.4) with ESMTP id r5BFfWHo015321; Tue, 11 Jun 2013 17:41:32 +0200 Received: (from ralf@localhost) by scotty.linux-mips.net (8.14.5/8.14.5/Submit) id r5BFfUol015320; Tue, 11 Jun 2013 17:41:30 +0200 Date: Tue, 11 Jun 2013 17:41:29 +0200 From: Ralf Baechle To: Markos Chandras Cc: linux-mips@linux-mips.org, Michal Marek , linux-kbuild@vger.kernel.org Subject: Re: [PATCH] MIPS: Kconfig: Set default value for the "Kernel code model" Message-ID: <20130611154129.GD13126@linux-mips.org> References: <1370944336-13703-1-git-send-email-markos.chandras@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1370944336-13703-1-git-send-email-markos.chandras@imgtec.com> User-Agent: Mutt/1.5.21 (2010-09-15) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 36836 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On Tue, Jun 11, 2013 at 10:52:16AM +0100, Markos Chandras wrote: (Adding the kconfig maintainer and mailing list to cc.) > Certain randconfigs may not select neither CONFIG_32BIT nor > CONFIG_64BIT which can lead to build problems and to the following > Kbuild warning: > > .config:154:warning: symbol value '' invalid for PHYSICAL_START > > Signed-off-by: Markos Chandras > Acked-by: Steven J. Hill Systems are supposed to set if they support 32 bit kernels and/or 64 bit kernels in arch/mips/Kconfig. The behaviour you're reporting happens if the default system (which happens to be SGI_IP22) supports both kernel models, that is SYS_SUPPORTS_32BIT_KERNEL and SYS_SUPPORTS_64BIT_KERNEL are set. Then "make randconfig" will generate a .config with neiher CONFIG_32BIT nor CONFIG_64BIT set. Just defaulting to CONFIG_32BIT as in your patch http://patchwork.linux-mips.org/patch/5377/ isn't really a good solution because for some platforms 32 bit kernels, for others 64 bit kernels are preferred so I tried to implement something like choice prompt "Kernel code model" default 32BIT if SYS_32BIT_KERNEL_PREFERRED default 64BIT if SYS_64BIT_KERNEL_PREFERRED and have individual platforms set their preferred kernel variant. And I got more odd Kconfig behaviour, getting both choice values 32BIT and 64BIT set for some platforms. Another variant that only uses a single auxilliary symbol, SYS_64BIT_KERNEL_PREFERRED like this: choice prompt "Kernel code model" default 32BIT if !SYS_64BIT_KERNEL_PREFERRED default 64BIT if SYS_64BIT_KERNEL_PREFERRED still results in CONFIG_32BIT=y CONFIG_64BIT=y So I'm not quite certain how to obtain the desired behaviour - but I appears highly unobvious to buggy on kconfig's side. Michal, can you shed some light? Ralf