diff mbox series

[22/23] kbuild: make wrapper Makefile more convenient for external modules

Message ID 20240917141725.466514-23-masahiroy@kernel.org (mailing list archive)
State New
Headers show
Series kbuild: support building external modules in a separate build directory | expand

Commit Message

Masahiro Yamada Sept. 17, 2024, 2:16 p.m. UTC
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: Masahiro Yamada <masahiroy@kernel.org>
---

 Makefile | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 9f0ba07e8f25..81603a50c757 100644
--- a/Makefile
+++ b/Makefile
@@ -641,10 +641,20 @@  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 = $(_vpath)" ; \
+	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