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author | Masahiro Yamada <yamada.m@jp.panasonic.com> | 2014-02-04 17:24:24 +0900 |
---|---|---|
committer | Tom Rini <trini@ti.com> | 2014-02-19 11:07:50 -0500 |
commit | 9e4140329ee9a787d0f96ac2829d618d47f7973f (patch) | |
tree | 6a40432f6f6723ba9ac5309076af17aec3bc0a9b /lib/Makefile | |
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 $(obj)=<sub-dir>" with a shorthand.)
This means the current working directory is always the top
of the output directory.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
Diffstat (limited to 'lib/Makefile')
-rw-r--r-- | lib/Makefile | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/Makefile b/lib/Makefile index 760340fbde..43b13d09e2 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -67,4 +67,4 @@ obj-$(CONFIG_BOOTP_RANDOM_DELAY) += rand.o obj-$(CONFIG_CMD_LINK_LOCAL) += rand.o # SEE README.arm-unaligned-accesses -$(obj)bzlib.o: CFLAGS += $(PLATFORM_NO_UNALIGNED) +$(obj)/bzlib.o: CFLAGS += $(PLATFORM_NO_UNALIGNED) |