From patchwork Mon Sep 14 21:49:11 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 47496 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n8ELnCso032334 for ; Mon, 14 Sep 2009 21:49:43 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756973AbZINVtj (ORCPT ); Mon, 14 Sep 2009 17:49:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757260AbZINVtj (ORCPT ); Mon, 14 Sep 2009 17:49:39 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:39641 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756973AbZINVti (ORCPT ); Mon, 14 Sep 2009 17:49:38 -0400 Received: from imap1.linux-foundation.org (imap1.linux-foundation.org [140.211.169.55]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id n8ELnCJo022509 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 14 Sep 2009 14:49:13 -0700 Received: from localhost.localdomain (localhost [127.0.0.1]) by imap1.linux-foundation.org (8.13.5.20060308/8.13.5/Debian-3ubuntu1.1) with ESMTP id n8ELnClV018750; Mon, 14 Sep 2009 14:49:12 -0700 Message-Id: <200909142149.n8ELnClV018750@imap1.linux-foundation.org> Subject: [patch 11/18] kconfig CROSS_COMPILE option To: sam@ravnborg.org Cc: linux-kbuild@vger.kernel.org, akpm@linux-foundation.org, roland@redhat.com From: akpm@linux-foundation.org Date: Mon, 14 Sep 2009 14:49:11 -0700 MIME-Version: 1.0 X-Spam-Status: No, hits=-3.512 required=5 tests=AWL, BAYES_00, OSDL_HEADER_SUBJECT_BRACKETED X-Spam-Checker-Version: SpamAssassin 3.2.4-osdl_revision__1.47__ X-MIMEDefang-Filter: lf$Revision: 1.188 $ X-Scanned-By: MIMEDefang 2.63 on 140.211.169.13 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org From: Roland McGrath This adds CROSS_COMPILE as a kconfig string so you can store it in .config. Then you can use plain "make" in the configured kernel build directory to do the right cross compilation without setting the command-line or environment variable every time. With this, you can set up different build directories for different kernel configurations, whether native or cross-builds, and then use the simple: make -C /build/dir M=module-source-dir idiom to build modules for any given target kernel, indicating which one by nothing but the build directory chosen. I tried a version that defaults the string with env="CROSS_COMPILE" so that in a "make oldconfig" with CROSS_COMPILE in the environment you can just hit return to store the way you're building it. But the kconfig prompt for strings doesn't give you any way to say you want an empty string instead of the default, so I punted that. Signed-off-by: Roland McGrath Cc: Sam Ravnborg Signed-off-by: Andrew Morton --- Makefile | 4 +++- init/Kconfig | 8 ++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff -puN Makefile~kconfig-cross_compile-option Makefile --- a/Makefile~kconfig-cross_compile-option +++ a/Makefile @@ -177,11 +177,13 @@ SUBARCH := $(shell uname -m | sed -e s/i # CROSS_COMPILE can be set on the command line # make CROSS_COMPILE=ia64-linux- # Alternatively CROSS_COMPILE can be set in the environment. +# A third alternative is to store a setting in .config so that plain +# "make" in the configured kernel build directory always uses that. # Default value for CROSS_COMPILE is not to prefix executables # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile export KBUILD_BUILDHOST := $(SUBARCH) ARCH ?= $(SUBARCH) -CROSS_COMPILE ?= +CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%) # Architecture as present in compile.h UTS_MACHINE := $(ARCH) diff -puN init/Kconfig~kconfig-cross_compile-option init/Kconfig --- a/init/Kconfig~kconfig-cross_compile-option +++ a/init/Kconfig @@ -76,6 +76,14 @@ config INIT_ENV_ARG_LIMIT variables passed to init from the kernel command line. +config CROSS_COMPILE + string "Cross-compiler tool prefix" + help + Same as running 'make CROSS_COMPILE=prefix-' but stored for + default make runs in this kernel build directory. You don't + need to set this unless you want the configured kernel build + directory to select the cross-compiler automatically. + config LOCALVERSION string "Local version - append to kernel release" help