Re: Romulus to use Virtual PNOR

[Stewart Smith <stewart@linux.ibm.com>]

Alexander Amelkin <a.amelkin@yadro.com> writes:
> 25.01.2019 10:40, Lei YU wrote:
>> This email is to notify that Romulus is going to use VirtualPNOR feature, if
>> no objections are received.
>>
>> It **impacts** to existing Romulus systems, that they must do PNOR code update
>> when the feature is enabled.
>>
>> A little background on this topic could be found at:
>> https://lists.ozlabs.org/pipermail/openbmc/2018-May/011822.html
>> https://lists.ozlabs.org/pipermail/openbmc/2018-November/014112.html
>>
>> I did not receive any feedback, so I choose to use VritualPNOR feature,
>> which has below benefits:
>> 1. It requires minor code changes for a system to switch to VirtualPNOR;
>> 2. It gets full features, including PNOR version, code verification, and code
>>    update via new interface;
>> 3. When OpenBMC switches to Redfish, it will get Redfish code update for free,
>>    because IBM will implement Redfish code update based on VirtualPNOR.
>>
>> The related changes are:
>> * OpenBMC: https://gerrit.openbmc-project.xyz/#/q/topic:ubifs-pnor-for-romulus
>> * op-build: https://github.com/open-power/op-build/pull/2578
>>
>> Any objections?
>
> Well, the main concern is how it will affect vesnin, which is P8-based (like palmetto).
>
> All this virtual PNOR functionality is based on mbox/hiomap, which is
> not supported for P8 in openpower firmware.

For various reasons, this is now changing, so you'll be able to do hiomap
on P8.

> As a result, we suspect that palmetto and (what concerns us most)
> vesnin will lose firmware update support completely.

I think this is a valid concern, and I'd be concerned if there's tight
coupling between VPNOR and the firmware update APIs.

-- 
Stewart Smith
OPAL Architect, IBM.