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| author | Sam Ravnborg <sam@ravnborg.org> | 2009-10-11 23:22:58 +0200 |
|---|---|---|
| committer | Sam Ravnborg <sam@ravnborg.org> | 2009-10-11 23:22:58 +0200 |
| commit | 2331d1a6cd3d6e580bc88b9a160066d9e1177fe1 (patch) | |
| tree | eba044f60a1fe478e864ead1dc1940a2b0a23b9f | |
| parent | c01226c3145d173a0d38f9d5b4f229cc23d99ae2 (diff) | |
| download | lwn-2331d1a6cd3d6e580bc88b9a160066d9e1177fe1.tar.gz lwn-2331d1a6cd3d6e580bc88b9a160066d9e1177fe1.zip | |
kbuild: revert "save ARCH & CROSS_COMPILE ..."
Revert commit 575543347b5baed0ca927cb90ba8807396fe9cc9
It caused following issues:
- On architectures where ARCH= setting is used to select between
32 and 64 bit this was no longer possible without "make mrproper"
- If ARCH was changed then kbuild refused to run "make mrproper"
because ARCH had changed
- When CROSS_COMPILE was changed people were asked to run "make mrproper"
but kbuild refused to run "make mrproper" because CROSS_COMPILE changed.
- Spaces in CROSS_COMPILE was not 'supported'
- If an non-existing ARCH= was used kbuild could get stuck
Lessons learned:
. Despite being simple and straghtforward people uses very different
approaches when building the kernel.
. CROSS_COMPILE is sometimes used for ccache despite cache being
only a CC frontend so one would have expected CC to be
used for this purpose.
. And obviously this was not tested widely enough.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | Makefile | 46 |
1 files changed, 2 insertions, 44 deletions
@@ -179,46 +179,9 @@ SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \ # Alternatively CROSS_COMPILE can be set in the environment. # Default value for CROSS_COMPILE is not to prefix executables # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile -# -# To force ARCH and CROSS_COMPILE settings include kernel.* files -# in the kernel tree - do not patch this file. export KBUILD_BUILDHOST := $(SUBARCH) - -# Kbuild save the ARCH and CROSS_COMPILE setting in kernel.* files. -# Restore these settings and check that user did not specify -# conflicting values. - -saved_arch := $(shell cat include/generated/kernel.arch 2> /dev/null) -saved_cross := $(shell cat include/generated/kernel.cross 2> /dev/null) - -ifneq ($(CROSS_COMPILE),) - ifneq ($(saved_cross),) - ifneq ($(CROSS_COMPILE),$(saved_cross)) - $(error CROSS_COMPILE changed from \ - "$(saved_cross)" to \ - to "$(CROSS_COMPILE)". \ - Use "make mrproper" to fix it up) - endif - endif -else - CROSS_COMPILE := $(saved_cross) -endif - -ifneq ($(ARCH),) - ifneq ($(saved_arch),) - ifneq ($(saved_arch),$(ARCH)) - $(error ARCH changed from \ - "$(saved_arch)" to "$(ARCH)". \ - Use "make mrproper" to fix it up) - endif - endif -else - ifneq ($(saved_arch),) - ARCH := $(saved_arch) - else - ARCH := $(SUBARCH) - endif -endif +ARCH ?= $(SUBARCH) +CROSS_COMPILE ?= # Architecture as present in compile.h UTS_MACHINE := $(ARCH) @@ -483,11 +446,6 @@ ifeq ($(config-targets),1) include $(srctree)/arch/$(SRCARCH)/Makefile export KBUILD_DEFCONFIG KBUILD_KCONFIG -# save ARCH & CROSS_COMPILE settings -$(shell mkdir -p include/generated && \ - echo $(ARCH) > include/generated/kernel.arch && \ - echo $(CROSS_COMPILE) > include/generated/kernel.cross) - config: scripts_basic outputmakefile FORCE $(Q)mkdir -p include/linux include/config $(Q)$(MAKE) $(build)=scripts/kconfig $@ |