Getting DIMM size in Redfish

[Lei YU]

After sending this email, it's found that there is an existing review
to add DIMM properties:
https://gerrit.openbmc-project.xyz/c/openbmc/phosphor-dbus-interfaces/+/24976

@Cheng C Yang Could you kindly share where the properties are implemented?
Thanks a lot!

On Fri, Oct 11, 2019 at 11:01 AM Lei YU <mine260309 at gmail.com> wrote:
>
> This mail is to discuss how to get DIMM size in Redfish (bmcweb).
>
> Currently, bmcweb does not report DIMM size because it's not
> implemented, and we are trying to implement this.
>
> The DIMM interface is defined in [phosphor-dbus-interface][1], which
> does not provide any metadata.
>
> For OpenPOWER systems, the size information is provided in `PrettyName`, e.g.
>
>     "PrettyName": "DDR4-2666 32GiB 64-bit ECC RDIMM"
>
> It is guaranteed to be a string with 5 parts, and we could parse this
> string to get the size.
> I do not know how other systems (e.g. x86 or ARM) get the DIMM size.
>
> During the [review][2] , Ed suggested creating an appropriate
> interface for the DIMM size.
>
> It's a good suggestion, but it could be complicated to be implemented:
> * The information is sent by host via inband IPMI as FRU;
> * In ipmid, the code to handle FRU is generic and part of the code is
> generated, so it could be hard to make a specific change for DIMM
> size.
>
> So the question to the community is, how other systems get the DIMM size?
> Knowing this, we could try to design a generic method to handle the case.
>
> Otherwise, we will have to write specific code, either in ipmid or in
> bmcweb, to get such specific values.
>
> Thanks!
>
> [1]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/xyz/openbmc_project/Inventory/Item/Dimm.interface.yaml
> [2]: https://gerrit.openbmc-project.xyz/c/openbmc/bmcweb/+/25754