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From:   Masahiro Yamada <yamada.masahiro@socionext.com>
Date:   Tue, 3 Sep 2019 23:31:18 +0900
Message-ID: <CAK7LNASMx7XBDUALd+UOj1jw=0kU-XoJBExCpSvKyQwV37mz7A@mail.gmail.com>
Subject: Re: [PATCH] riscv: add arch/riscv/Kbuild
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Albert Ou <aou@eecs.berkeley.edu>,
        Palmer Dabbelt <palmer@sifive.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        linux-riscv@lists.infradead.org
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On Mon, Sep 2, 2019 at 4:42 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Sat, Aug 31, 2019 at 10:04:53PM +0900, Masahiro Yamada wrote:
> > Kbuild support two file names, "Makefile" and "Kbuild"
> > for describing obj-y, obj-m, etc.
>
> <snipping the basic explanation, which is documented pretty well,
> I I think I full understand>
>
> > Similarly, arch/$(SRCARCH)/Makefile is very special
> > in that it is included from the top-level Makefile,
> > and specify arch-specific compiler flags etc.
> >
> > We can use arch/$(SRCARCH)/Kbuild
> > to specify obj-y, obj-m.
> > The top-level Makefile does not need to know
> > the directory structure under arch/$(SRCARCH)/.
> >
> > This is logical separation.
>
> But only if we document this specific split and eventually stop allowing
> to build objects from arch/$(SRCARCH)/Makefile.

I like this idea, but it would change the link order (i.e. probe order)

For example, I want move all drivers-y in arch/x86/Makefile
to arch/x86/Kbuild.

I do not know how much we care about the probe order.


>  And in my perfect world
> we'd eventually phase out the magic arch/$(SRCARCH)/Makefile entire=C5=80=
y.
> In addition to the normal Kbuild file we'd then have say (names entirely
> made up and probably not the best idea)
>
>   arch/$(SRCARCH)/flags.mk to set the various compiler flags and co
>   arch/$(SRCARCH)/targets.mk for extra arch-specific targets

I am not sure whether this split is a good idea.
What is the problem with having the single arch-Makefile?


--=20
Best Regards
Masahiro Yamada