Re: [PATCH 1/4] board: spacemit: add SpacemiT K3 Pico-ITX

[Yixun Lan <dlan@kernel.org>]

Hi Yao,

On 18:00 Wed 23 Sep     , Yao Zi wrote:
> On Wed, Sep 23, 2026 at 12:46:45PM +0000, Yixun Lan wrote:
> > Add initial support for K3 Pico-ITX board, in this version, the DRAM
> > information is parsed from DTS "/memory" node. And with UART enabled,
> > the U-Boot serial console works fine now.
> > 
> > Signed-off-by: Yixun Lan <dlan@kernel.org>
> > ---
> >  arch/riscv/Kconfig            |  5 +++++
> >  arch/riscv/cpu/k3/Kconfig     | 18 ++++++++++++++++++
> >  arch/riscv/cpu/k3/Makefile    |  5 +++++
> >  arch/riscv/cpu/k3/dram.c      | 29 +++++++++++++++++++++++++++++
> >  board/spacemit/k3/Kconfig     | 30 ++++++++++++++++++++++++++++++
> >  board/spacemit/k3/MAINTAINERS |  8 ++++++++
> >  board/spacemit/k3/Makefile    |  5 +++++
> >  board/spacemit/k3/board.c     |  4 ++++
> >  include/configs/k3.h          | 13 +++++++++++++
> >  9 files changed, 117 insertions(+)
> 
> ...
> 
> > diff --git a/arch/riscv/cpu/k3/dram.c b/arch/riscv/cpu/k3/dram.c
> > new file mode 100644
> > index 00000000000..203d72a5da1
> > --- /dev/null
> > +++ b/arch/riscv/cpu/k3/dram.c
> > @@ -0,0 +1,29 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
> > + */
> > +
> > +#include <fdtdec.h>
> > +#include <init.h>
> > +#include <linux/sizes.h>
> > +#include <asm/global_data.h>
> 
> Please sort the headers alphabetically.
> 
Ok, will do

> > +DECLARE_GLOBAL_DATA_PTR;
> > +
> > +int dram_init(void)
> > +{
> > +	return fdtdec_setup_mem_size_base();
> > +}
> > +
> > +int dram_init_banksize(void)
> > +{
> > +	return fdtdec_setup_memory_banksize();
> > +}
> > +
> > +phys_addr_t board_get_usable_ram_top(phys_size_t total_size)
> > +{
> > +	if (gd->ram_size > SZ_2G)
> > +		return gd->ram_base + SZ_2G;
> 
> What's the intention of this limitation?
> 
This is a copy & paste from k1's implementation while K1 has discrete
memory layout which 0x8000 0000 - 0xFFFF FFFF is iomem space

For K3, there is no such problem, so no need this function
> > +	return gd->ram_base + gd->ram_size;
> > +}
> 
> ...
> 
> > diff --git a/board/spacemit/k3/Makefile b/board/spacemit/k3/Makefile
> > new file mode 100644
> > index 00000000000..bd5343be789
> > --- /dev/null
> > +++ b/board/spacemit/k3/Makefile
> > @@ -0,0 +1,5 @@
> > +# SPDX-License-Identifier: GPL-2.0-or-later
> > +#
> > +# Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
> > +
> > +obj-y := board.o
> > diff --git a/board/spacemit/k3/board.c b/board/spacemit/k3/board.c
> > new file mode 100644
> > index 00000000000..29994e49ce8
> > --- /dev/null
> > +++ b/board/spacemit/k3/board.c
> > @@ -0,0 +1,4 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
> > + */
> 
> I think it makes sense to omit the source if it's empty for now.
> 
Ok, fair

-- 
Yixun Lan (dlan)