Re: [PATCH 0/2] riscv: cv1800b: Milk-V Duo boot fixes

[Hiago De Franco <hfranco@baylibre.com>]

Hello,

On Wed, Oct 07, 2026 at 09:48:59PM +0000, Yao Zi wrote:
> On Wed, Sep 30, 2026 at 09:17:48AM -0300, Hiago De Franco wrote:
> > This series fixes two problems on the Sophgo CV1800B/SG2002 Milk-V Duo
> > boards.
> > 
> > Patch 1 fixes the fdtfile environment variable of the Milk-V Duo 256M.
> > CONFIG_DEFAULT_DEVICE_TREE is a quoted string, so the quotes ended up
> > in the environment.
> > 
> > Patch 2 keeps U-Boot out of the memory reserved for the coprocessor
> > firmware. The upstream devicetrees reserve the end of DRAM as a no-map
> > region, but U-Boot relocates to ram_top, which is the end of DRAM, so
> > it lands inside that region.
> 
> I think the issue solved by PATCH 2 is introduced during switching to
> upstream devicetree? Could you please cooperate with Zhuxu so nothing
> is broken at the first place? Thanks.

Thanks for the review, you are right. The issue only shows up once the
boards switch to the upstream devicetrees from Zhuxu's series, and
Andrei's patches that drop the coprocessor reserved-memory nodes are
already in the Sophgo tree for linux-next:

  6645398c4621 ("riscv: dts: sophgo: cv1800b-milkv-duo: drop reserved memory node")
  60e4cafd3090 ("riscv: dts: sophgo: sg2002-milkv-duo256m: drop reserved memory node")

I tested Zhuxu's v5 plus these two commits applied to dts/upstream,
without my patch 2, on both Milk-V Duo 64M and 256M. The reserved memory
error is gone and U-Boot relocates to the top of DRAM as before:

  Duo 64M:  relocaddr = 0x83f79000
  Duo 256M: relocaddr = 0x8ff6e000

So I will drop patch 2 and send a v2 with only the fdtfile fix.

Zhuxu (Cc'd), to avoid breaking these boards in between, could you carry
those two devicetree changes in your series, or should we wait for the
next dts/upstream sync that includes them before your series is merged?

> 
> Regards,
> Yao Zi
> 
> > This was tested on both Milk-V Duo 64M and 256M (CV1800B and SG2002).
> > 
> > Signed-off-by: Hiago De Franco <hfranco@baylibre.com>
> > ---
> > Hiago De Franco (2):
> >       board: sophgo: milkv_duo_256m: fix fdtfile quoting
> >       riscv: cpu: cv1800b: keep U-Boot out of reserved memory

Best regards,
-- 
Hiago