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References: <20210604120639.1447869-1-alex@ghiti.fr>
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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Fri, 4 Jun 2021 15:08:05 +0200
Message-ID: <CAK8P3a1TiSNoqUEjTaqPyqnU8d0-p-yZkrsvmXt5fo4Rkfue_w@mail.gmail.com>
Subject: Re: [PATCH -fixes] riscv: Fix BUILTIN_DTB for sifive and microchip soc
To:     Alexandre Ghiti <alex@ghiti.fr>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        DTML <devicetree@vger.kernel.org>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Fri, Jun 4, 2021 at 2:06 PM Alexandre Ghiti <alex@ghiti.fr> wrote:
>
> Fix BUILTIN_DTB config which resulted in a dtb that was actually not built
> into the Linux image: in the same manner as Canaan soc does, create an object
> file from the dtb file that will get linked into the Linux image.
>
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>

Along the same lines as the comment that Jisheng Zhang made on the fixed
address, building a dtb into the kernel itself fundamentally breaks generic
kernel images.

I can understand using it on K210, which is extremely limited and wouldn't
run a generic kernel anyway, but for normal platforms like microchip and
sifive, it would be better to disallow CONFIG_BUILTIN_DTB in Kconfig
and require a non-broken boot loader.

      Arnd