Re: [PATCH v2 2/2] ARM: dts: aspeed: add asrock x470d4u bmc

[Tan Siewert]

On 20.10.25 11:40, Zev Weiss wrote:
> On Sat, Oct 11, 2025 at 04:21:20AM PDT, Tan Siewert wrote:
> > The ASRock Rack X470D4U X470D4U is a single-socket X470-based microATX
> > motherboard for Ryzen processors with an AST2500 BMC and either 32MB or
> > 64MB SPI flash.
> >
> > This mainboard exists in three known "flavors" which only differ in the
> > used host NIC, the BMC SPI size and some parts that may be un-populated.
> >
> > To keep the complexity low with the BMC SPI, use the 32MB layout
> > regardless of the used SPI or mainboard flavor.

*snip*

> Hmm -- I can see the simplicity argument, but it seems a bit of a shame 
> to let the other 32MB go to waste on boards with 64MB chips (especially 
> given how tight a fit OpenBMC is getting in 32MB these days).

Agreed.

> Could we maybe have an aspeed-bmc-asrock-x470d4u-64.dts alongside this 
> one that #includes it and then drops in the 64M layout over the default 
> 32?  You could then arrange for a flag in the OpenBMC bitbake recipes to 
> opt in to using that dts if you want to.

I implemented this idea in one of my first drafts [1], but there were 
questions on the OpenBMC Discord if the additional 32MB of space are 
really needed, given that the 64MB SPI is only available on an ODM 
variant by default.

[1] https://gerrit.openbmc.org/c/openbmc/openbmc/+/82262/4

Cheers,
Tan

> Zev