From ffee0de411fd4f74f3b788892eeb075abbf26c52 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Thu, 20 Dec 2012 21:51:55 +0000 Subject: [PATCH] x86: Default to ARCH=x86 to avoid overriding CONFIG_64BIT It is easy to waste a bunch of time when one takes a 32-bit .config from a test machine and try to build it on a faster 64-bit system, and its existing setting of CONFIG_64BIT=n gets *changed* to match the build host. Similarly, if one has an existing build tree it is easy to trash an entire build tree that way. This is because the default setting for $ARCH when discovered from 'uname' is one of the legacy pre-x86-merge values (i386 or x86_64), which effectively force the setting of CONFIG_64BIT to match. We should default to ARCH=x86 instead, finally completing the merge that we started so long ago. This patch preserves the behaviour of the legacy ARCH settings for commands such as: make ARCH=x86_64 randconfig make ARCH=i386 randconfig ... since making the value of CONFIG_64BIT actually random in that situation is not desirable. In time, perhaps we can retire this legacy use of the old ARCH= values. We already have a way to override values for *any* config option, using $KCONFIG_ALLCONFIG, so it could be argued that we don't necessarily need to keep ARCH={i386,x86_64} around as a special case just for overriding CONFIG_64BIT. We'd probably at least want to add a way to override config options from the command line ('make CONFIG_FOO=y oldconfig') before we talk about doing that though. Signed-off-by: David Woodhouse Link: http://lkml.kernel.org/r/1356040315.3198.51.camel@shinybook.infradead.org Signed-off-by: H. Peter Anvin --- Makefile | 3 ++- arch/x86/Kconfig | 2 +- arch/x86/Makefile | 4 ++++ arch/x86/configs/i386_defconfig | 1 + 4 files changed, 8 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 540f7b2..9a07340 100644 --- a/Makefile +++ b/Makefile @@ -165,7 +165,8 @@ export srctree objtree VPATH # then ARCH is assigned, getting whatever value it gets normally, and # SUBARCH is subsequently ignored. -SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \ +SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \ + -e s/sun4u/sparc64/ \ -e s/arm.*/arm/ -e s/sa110/arm/ \ -e s/s390x/s390/ -e s/parisc64/parisc/ \ -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \ diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 46c3bff..9084c7b 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1,7 +1,7 @@ # Select 32 or 64 bit config 64BIT bool "64-bit kernel" if ARCH = "x86" - default ARCH = "x86_64" + default ARCH != "i386" ---help--- Say yes to build a 64-bit kernel - formerly known as x86_64 Say no to build a 32-bit kernel - formerly known as i386 diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 05afcca..fa981ca 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -2,7 +2,11 @@ # select defconfig based on actual architecture ifeq ($(ARCH),x86) + ifeq ($(shell uname -m),x86_64) + KBUILD_DEFCONFIG := x86_64_defconfig + else KBUILD_DEFCONFIG := i386_defconfig + endif else KBUILD_DEFCONFIG := $(ARCH)_defconfig endif diff --git a/arch/x86/configs/i386_defconfig b/arch/x86/configs/i386_defconfig index 5598547..9444708 100644 --- a/arch/x86/configs/i386_defconfig +++ b/arch/x86/configs/i386_defconfig @@ -1,3 +1,4 @@ +# CONFIG_64BIT is not set CONFIG_EXPERIMENTAL=y # CONFIG_LOCALVERSION_AUTO is not set CONFIG_SYSVIPC=y -- 2.7.4