Re: [PATCH 3/5] riscv: dts: spacemit: k3-com260: Add SPI NOR flash

["Troy Mitchell" <troy.mitchell@linux.spacemit.com>]

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On Sat, 07 Nov 2026 12:48:33 +0000, Troy Mitchell wrote:
> On Fri, 6 Nov 2026 17:25:48 +0100, Sarah Emery wrote:
> > > +			uboot@210000 {
> > > +				reg = <0x210000 0x5f0000>;
> > > +			};
> >
> > This partition ends at 0x800000. On the CoM260 with EDK2,
> > 0x700000 to 0x7c0000 holds the variable store (NVRAM and FTW), so
> > reflashing this partition from Linux would erase it.
> >
> > I think we could split it like this:
> >
> >     uboot@210000 {
> >        reg = <0x210000 0x4f0000>;
> >     };
> >
> >     var@700000 {
> >        reg = <0x700000 0xc0000>;
> >        read-only;
> >     };
> >
> > What do you think?
>
> The layout here is the one used by the SpacemiT boot firmware for K3,
> where U-Boot owns everything from 0x210000 to the end of the flash.
> The EDK2 that SpacemiT ships for K3 (including the CoM260
> configurations) keeps its variables in memory and does not use the
> flash for them, so it has nothing at 0x700000.
>
> Which EDK2 build places the variable store at 0x700000?
Sorry, I checked an outdated EDK2 tree. The current SpacemiT EDK2 for
K3 does store the variables in flash, in a separate region pinned at
0x700000 with size 0xc0000, and the firmware image itself goes at
0x210000. So you are right, and I'll split the partition the way you
suggested in v2.

> > The Pico-ITX node also uses 0x5f0000, but I think it should be
> > modified to split out the var part too if it makes sense here.
>
> Same answer as above.
For Pico-ITX, the same layout applies, so its DTS should get the same
split in a separate patch.

-- 
Troy Mitchell

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