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 $(obj)=" with a shorthand.) This means the current working directory is always the top of the output directory. Signed-off-by: Masahiro Yamada Tested-by: Gerhard Sittig --- arch/blackfin/cpu/Makefile | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/blackfin/cpu/Makefile') diff --git a/arch/blackfin/cpu/Makefile b/arch/blackfin/cpu/Makefile index a61594a..369dc74 100644 --- a/arch/blackfin/cpu/Makefile +++ b/arch/blackfin/cpu/Makefile @@ -25,9 +25,9 @@ extra-y += check_initcode # make sure our initcode (which goes into LDR) does not # have relocs or external references -$(obj)initcode.o: CFLAGS += -fno-function-sections -fno-data-sections +$(obj)/initcode.o: CFLAGS += -fno-function-sections -fno-data-sections READINIT = env LC_ALL=C $(CROSS_COMPILE)readelf -s $< -$(obj)check_initcode: $(obj)initcode.o +$(obj)/check_initcode: $(obj)/initcode.o ifneq ($(CONFIG_BFIN_BOOT_MODE),BFIN_BOOT_BYPASS) @if $(READINIT) | grep '\.*\' ; then \ echo "$< contains external references!" 1>&2 ; \ @@ -35,7 +35,7 @@ ifneq ($(CONFIG_BFIN_BOOT_MODE),BFIN_BOOT_BYPASS) fi endif -$(obj)init.lds: init.lds.S +$(obj)/init.lds: $(src)/init.lds.S $(CPP) $(CPPFLAGS) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P $^ -o $@ -$(obj)init.elf: $(obj)init.lds $(obj)init.o $(obj)initcode.o +$(obj)/init.elf: $(obj)/init.lds $(obj)/init.o $(obj)/initcode.o $(LD) $(LDFLAGS) -T $^ -o $@ -- cgit v1.1