kernel/linux.git/arch/arm/Kbuild, branch v6.12.80

kbuild: use $(src) instead of $(srctree)/$(src) for source directory

2024-05-09T19:34:52+00:00

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier

kbuild: use more subdir- for visiting subdirectories while cleaning

2021-10-24T04:49:46+00:00

Documentation/kbuild/makefiles.rst suggests to use "archclean" for cleaning arch/$(SRCARCH)/boot/, but it is not a hard requirement. Since commit d92cc4d51643 ("kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild"), we can use the "subdir- += boot" trick for all architectures. This can take advantage of the parallel option (-j) for "make clean". I also cleaned up the comments in arch/$(SRCARCH)/Makefile. The "archdep" target no longer exists. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Acked-by: Geert Uytterhoeven Acked-by: Michael Ellerman (powerpc)

ARM: 8981/1: add arch/arm/Kbuild

2020-07-21T15:33:35+00:00

Use the standard obj-y form to specify the sub-directories under arch/arm/. No functional change intended. Signed-off-by: Masahiro Yamada Signed-off-by: Russell King