kbuild: Don't fail if include/asm symlink exists
From: Andreas Gruenbacher <agruen@suse.de>
We're having the following situation: There are user-space applications
that include kernel headers directly. With a completely unconfigured
/usr/src/linux tree, including most headers fails because essential
files are not there:
include/asm
include/linux/autoconf.h
include/linux/version.h
So we create these files. On the other hand, we want to use
/usr/src/linux as read-only source for building kernels or additional
modules. Now when building a kernel with a separate output directory
(O=), there is a check in the main makefile for the include/asm symlink.
There is no real need for this check: if we ensure that
$(objdir)/include/asm is always created as the patch does,
$(srctree)/include/asm becomes irrelevant.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/Makefile b/Makefile
index 5d0ecf11..a8d41b7 100644
--- a/Makefile
+++ b/Makefile
@@ -767,7 +767,7 @@
prepare2:
ifneq ($(KBUILD_SRC),)
@echo ' Using $(srctree) as source for kernel'
- $(Q)if [ -h $(srctree)/include/asm -o -f $(srctree)/.config ]; then \
+ $(Q)if [ -f $(srctree)/.config ]; then \
echo " $(srctree) is not clean, please run 'make mrproper'";\
echo " in the '$(srctree)' directory.";\
/bin/false; \
@@ -779,7 +779,8 @@
# prepare1 creates a makefile if using a separate output directory
prepare1: prepare2 outputmakefile
-prepare0: prepare1 include/linux/version.h include/asm include/config/MARKER
+prepare0: prepare1 include/linux/version.h $(objtree)/include/asm \
+ include/config/MARKER
ifneq ($(KBUILD_MODULES),)
$(Q)rm -rf $(MODVERDIR)
$(Q)mkdir -p $(MODVERDIR)
@@ -818,7 +819,7 @@
# hard to detect, but I suppose "make mrproper" is a good idea
# before switching between archs anyway.
-include/asm:
+$(objtree)/include/asm:
@echo ' SYMLINK $@ -> include/asm-$(ARCH)'
$(Q)if [ ! -d include ]; then mkdir -p include; fi;
@ln -fsn asm-$(ARCH) $@