From 9e4140329ee9a787d0f96ac2829d618d47f7973f Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 4 Feb 2014 17:24:24 +0900 Subject: 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 " 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=" syntax for descending into sub-directories. (We can write it like "make $(obj)=" with a shorthand.) This means the current working directory is always the top of the output directory. Signed-off-by: Masahiro Yamada Tested-by: Gerhard Sittig --- dts/Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'dts/Makefile') diff --git a/dts/Makefile b/dts/Makefile index 6c7198f65f..d81f32d914 100644 --- a/dts/Makefile +++ b/dts/Makefile @@ -26,7 +26,7 @@ DTC_FLAGS := -R 4 -p 0x1000 \ # Use a constant name for this so we can access it from C code. # objcopy doesn't seem to allow us to set the symbol name independently of # the filename. -DT_BIN := $(obj)dt.dtb +DT_BIN := $(obj)/dt.dtb $(DT_BIN): $(TOPDIR)/board/$(VENDOR)/dts/$(DEVICE_TREE).dts $(CPP) $(DTS_CPPFLAGS) $< -o $(DT_BIN).dts.tmp @@ -38,7 +38,7 @@ process_lds = \ # Run the compiler and get the link script from the linker GET_LDS = $(CC) $(CFLAGS) $(LDFLAGS) -Wl,--verbose 2>&1 -$(obj)dt.o: $(DT_BIN) +$(obj)/dt.o: $(DT_BIN) # We want the output format and arch. # We also hope to win a prize for ugliest Makefile / shell interaction # We look in the LDSCRIPT first. @@ -62,7 +62,7 @@ $(obj)dt.o: $(DT_BIN) \ cd $(dir ${DT_BIN}) && \ $(OBJCOPY) -I binary -O $${oformat} -B $${oarch} \ - $(notdir ${DT_BIN}) $@ + $(notdir ${DT_BIN}) $(notdir $@) rm $(DT_BIN) obj-$(CONFIG_OF_EMBED) := dt.o -- cgit v1.2.1