On Mon, Aug 26, 2019 at 8:35 PM Christoph Hellwig <h...@infradead.org> wrote: > > On Wed, Aug 21, 2019 at 06:26:58PM +0900, Masahiro Yamada wrote: > > Use the standard obj-y form to specify the sub-directories under > > arch/riscv/. No functional change intended. > > > > Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com> > > Do you have a document what the grand scheme here is?
There is a small documentation about "Makefile" vs "Kbuild" in Documentation/kbuild/modules.rst section 3.2 It is talking about external modules, but the benefit applies to arch/$(SRCARCH)/Kbuild as well. arch/$(SRCARCH)/Makefile is included by the top Makefile to specify arch-specific compiler flags, etc. On the other hand, arch/$(SRCARCH)/Kbuild, if exists, is included when Kbuild actually descends into arch/$(SRCARCH)/. This allows you to hierarchize the sub-directories to visit instead of specifying everything in flat in arch/$(SRCARCH)/Makefile. Major architectures are already doing this. See arch/x86/Kbuild arch/sparc/Kbuild arch/powerpc/Kbuild etc. (and arm64 also adopted this recently) The trick is "Kbuild" has precedence over "Makefile". If you are interested in the actual code, see line 41 of scripts/Makefile.build > Less of the magic > in arch/$(ARCH)/Makefile sounds like a good idea, but unless we have > a very specific split between the kbuild makefile and various override > I fear just splitting things up into two files doesn't really help much. Why not? -- Best Regards Masahiro Yamada