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From:   Zhangjin Wu <falcon@tinylab.org>
To:     w@1wt.eu
Cc:     arnd@arndb.de, falcon@tinylab.org, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, thomas@t-8ch.de
Subject: Re: [PATCH v2 12/14] selftests/nolibc: add tinyconfig target
Date:   Tue, 25 Jul 2023 23:13:33 +0800
Message-Id: <20230725151333.37939-1-falcon@tinylab.org>
In-Reply-To: <20230722130759.GL17311@1wt.eu>
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> On Wed, Jul 19, 2023 at 09:30:30PM +0800, Zhangjin Wu wrote:
> > The original tinyconfig target only enables minimal kernel config
> > options, it can speed up the kernel build and nolibc test a lot and also
> > brings us with smaller kernel image size.
> > 
> > But the default enabled options are not enough for qemu boot and console
> > print, some additional config options should be added for every
> > architecture individually.
> > 
> > Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
> > ---
> >  tools/testing/selftests/nolibc/Makefile | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
> > index eec2935672ad..f42782fa78a9 100644
> > --- a/tools/testing/selftests/nolibc/Makefile
> > +++ b/tools/testing/selftests/nolibc/Makefile
> > @@ -218,6 +218,9 @@ mrproper:
> >  defconfig:
> >  	$(Q)$(MAKE_KERNEL) $(DEFCONFIG) prepare
> >  
> > +tinyconfig:
> > +	$(Q)$(MAKE_KERNEL) tinyconfig prepare
> 
> So for the same reasons as defconfig above, I'd actually keep mrproper
> here.

Ok, let's add mrproper back here, since tinyconfig is fast enough, so, a
mrproper is not that time cost and a cleanup is really good prepare.

> And if we figure that tinyconfig is never called by the user
> directly but as a dependency from the makefile itself or scripts,
> then we likely don't even need to create a visible entry for it.
>

Great idea,

At first, tinyconfig can be triggered by something like:

    $ make run defconfig DEFCONFIG=tinyconfig

Perhaps we can let $(KERNEL_CONFIG) depends on the top-level
'tinyconfig' and trigger it by default:

    $(KERNEL_CONFIG):
	$(Q)if [ ! -f "$(KERNEL_CONFIG)" ]; then $(MAKE_KERNEL) --no-print-directory mrproper tinyconfig prepare; fi

Of course, we should triger the extra config above.

But this change must delay after we add tinyconfig support for all of
the nolibc supported architectures. before that, we should use
'defconfig' as we do currently.

So, it may be ok for us to drop this patch, but we also need to update
some commit messages who uses tinyconfig target directly.

Thanks,
Zhangjin

> Willy