From: Inochi Amaoto <inochiama@gmail.com>
To: Andrei Lalaev <andrey.lalaev@gmail.com>,
Samuel Holland <samuel.holland@sifive.com>
Cc: Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Paul Walmsley <pjw@kernel.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Alexandre Ghiti <alex@ghiti.fr>, Chen Wang <chen.wang@linux.dev>,
Inochi Amaoto <inochiama@gmail.com>,
devicetree@vger.kernel.org, sophgo@lists.linux.dev,
linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] riscv: dts: sophgo: sg2000-milkv-duo-s: reserve memory for RTOS
Date: Thu, 17 Sep 2026 10:02:10 +0800 [thread overview]
Message-ID: <aqtKAuoVSCxcts52@inochi.infowork> (raw)
In-Reply-To: <6e4b5c98-7d48-4629-a6a0-4d930327f9a0@sifive.com>
On Wed, Sep 16, 2026 at 12:10:23PM -0500, Samuel Holland wrote:
> Hi Andrei,
>
> On 2026-09-16 11:06 AM, Andrei Lalaev wrote:
> > The FSBL loads the coprocessor firmware into the last 2 MB of RAM.
> > Reserve this region to prevent Linux from using it.
>
> If the FSBL wants to reserve some RAM, it should modify the devicetree at
> runtime to add that reservation. Adding the reservation here creates an
> unnecessary ABI surface between the FSBL and all consumers of the devicetree.
>
> Regards,
> Samuel
>
This is fair, and the fact is that the current fsbl can disable
coprocessor in its configuration. So I will not take this patch
and maybe do a cleanup for existed devicetree if I have enough
time for it.
Regards,
Inohci
> > Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
> > ---
> > arch/riscv/boot/dts/sophgo/sg2000-milkv-duo-s.dts | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/arch/riscv/boot/dts/sophgo/sg2000-milkv-duo-s.dts b/arch/riscv/boot/dts/sophgo/sg2000-milkv-duo-s.dts
> > index 78a257839f6f..693c9fd7b771 100644
> > --- a/arch/riscv/boot/dts/sophgo/sg2000-milkv-duo-s.dts
> > +++ b/arch/riscv/boot/dts/sophgo/sg2000-milkv-duo-s.dts
> > @@ -22,6 +22,17 @@ chosen {
> > stdout-path = "serial0:115200n8";
> > };
> >
> > + reserved-memory {
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > + ranges;
> > +
> > + coprocessor_rtos: region@9fe00000 {
> > + reg = <0x9fe00000 0x200000>;
> > + no-map;
> > + };
> > + };
> > +
> > wifi_pwrseq: wifi-pwrseq {
> > compatible = "mmc-pwrseq-simple";
> > reset-gpios = <&porta 15 GPIO_ACTIVE_LOW>;
> >
> > ---
> > base-commit: 9b87fdc9af2fbfcdb5c24a64139685ef80f6573f
> > change-id: 20260916-milkv-duo-s-rtos-memory-7a94933e35bd
> >
> > Best regards,
> > --
> > Andrei Lalaev <andrey.lalaev@gmail.com>
> >
> >
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
>
next prev parent reply other threads:[~2026-09-17 2:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-16 16:06 Andrei Lalaev
2026-09-16 17:10 ` Samuel Holland
2026-09-17 2:02 ` Inochi Amaoto [this message]
2026-09-17 3:27 ` Andrei Lalaev
2026-09-16 18:34 ` Yao Zi
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