diff options
| author | Masahiro Yamada | 2014-02-04 17:24:24 +0900 |
|---|---|---|
| committer | Tom Rini | 2014-02-19 11:07:50 -0500 |
| commit | 9e4140329ee9a787d0f96ac2829d618d47f7973f (patch) | |
| tree | 6a40432f6f6723ba9ac5309076af17aec3bc0a9b /scripts/Kbuild.include | |
| parent | d958002589cb724907e8d4360d546403d1e6b7d8 (diff) | |
kbuild: change out-of-tree build
This commit changes the working directory
where the build process occurs.
Before this commit, build process occurred under the source
tree for both in-tree and out-of-tree build.
That's why we needed to add $(obj) prefix to all generated
files in makefiles like follows:
$(obj)u-boot.bin: $(obj)u-boot
Here, $(obj) is empty for in-tree build, whereas it points
to the output directory for out-of-tree build.
And our old build system changes the current working directory
with "make -C <sub-dir>" syntax when descending into the
sub-directories.
On the other hand, Kbuild uses a different idea
to handle out-of-tree build and directory descending.
The build process of Kbuild always occurs under the output tree.
When "O=dir/to/store/output/files" is given, the build system
changes the current working directory to that directory and
restarts the make.
Kbuild uses "make -f $(srctree)/scripts/Makefile.build obj=<sub-dir>"
syntax for descending into sub-directories.
(We can write it like "make $(obj)=<sub-dir>" with a shorthand.)
This means the current working directory is always the top
of the output directory.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
Diffstat (limited to 'scripts/Kbuild.include')
| -rw-r--r-- | scripts/Kbuild.include | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index ca5fd56ca25..6113c13d161 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -165,9 +165,7 @@ ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2)) # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= # Usage: # $(Q)$(MAKE) $(build)=dir -#build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj -# temporary -build := -f $(srctree)/scripts/Makefile.build -C +build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj ### # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= |