After cross-compiling the kernel, "make mrproper" should be executed with the proper ARCH= option. Otherwise, stale objects will remain under arch/$(SRCARCH)/. One bad scenario is like this: $ make ARCH=arm defconfig all # cross-compile the kernel for arm $ make mrproper # mrproper for host-arch (i.e. x86) $ make ARCH=arm O=build_dir defconfig all If you miss ARCH= for mrproper and cross-compile the kernel with O= and ARCH= options, Kbuild will happily start to build, but may fail due to stale objects in the srctree. If $(srctree)/arch/$(SRCARCH)/include/generated/ exists, let's stop the out-of-tree build. To detect this, mrproper should clean only arch/$(SRCARCH)/include/generated/. Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> --- Makefile | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 10643c3..17945ce 100644 --- a/Makefile +++ b/Makefile @@ -1091,7 +1091,9 @@ PHONY += prepare archprepare prepare1 prepare3 prepare3: include/config/kernel.release ifneq ($(srctree),.) @$(kecho) ' Using $(srctree) as source for kernel' - $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \ + $(Q)if [ -f $(srctree)/.config -o \ + -d $(srctree)/include/config -o \ + -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \ echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \ echo >&2 " in the '$(srctree)' directory.";\ /bin/false; \ @@ -1350,7 +1352,7 @@ CLEAN_DIRS += $(MODVERDIR) include/ksym # Directories & files removed with 'make mrproper' MRPROPER_DIRS += include/config usr/include include/generated \ - arch/*/include/generated .tmp_objdiff + arch/$(SRCARCH)/include/generated .tmp_objdiff MRPROPER_FILES += .config .config.old .version \ Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \ signing_key.pem signing_key.priv signing_key.x509 \ -- 2.7.4
