Commit a2a45ebe authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

kbuild: make wrapper Makefile more convenient for external modules 



When Kbuild starts building in a separate output directory, it generates
a wrapper Makefile, allowing you to invoke 'make' from the output
directory.

This commit makes it more convenient, so you can invoke 'make' without
M= or MO=.

First, you need to build external modules in a separate directory:

  $ make M=/path/to/module/source/dir MO=/path/to/module/build/dir

Once the wrapper Makefile is generated in /path/to/module/build/dir,
you can proceed as follows:

  $ cd /path/to/module/build/dir
  $ make

Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Reviewed-by: default avatarNicolas Schier <nicolas@fjasle.eu>
parent 822b11a7

Makefile

+11 −1
Original line number Diff line number Diff line
@@ -642,10 +642,20 @@ ifdef building_out_of_srctree 
# At the same time when output Makefile generated, generate .gitignore to

# ignore whole output directory



ifdef KBUILD_EXTMOD

print_env_for_makefile = \

	echo "export KBUILD_OUTPUT = $(objtree)"; \

	echo "export KBUILD_EXTMOD = $(realpath $(srcroot))" ; \

	echo "export KBUILD_EXTMOD_OUTPUT = $(CURDIR)"

else

print_env_for_makefile = \

	echo "export KBUILD_OUTPUT = $(CURDIR)"

endif



quiet_cmd_makefile = GEN     Makefile

      cmd_makefile = { \

	echo "\# Automatically generated by $(abs_srctree)/Makefile: don't edit"; \

	echo "export KBUILD_OUTPUT = $(CURDIR)"; \

	$(print_env_for_makefile); \

	echo "include $(abs_srctree)/Makefile"; \

	} > Makefile