phosphor-ipmi-flash: Update over eSPI interface

[Patrick Venture]

On Mon, Sep 9, 2019 at 7:01 AM Oskar Senft <osk at google.com> wrote:
>
> Hi Harry
>
> What's the behavior on eSPI? I assume you still have the aspeed-lpc-ctrl enabled, right?
>
> Thanks
> Oskar.
>
> On Mon, Sep 9, 2019 at 4:41 AM Harry Sung1 <hsung1 at lenovo.com> wrote:
>>
>> Hi Patrick,
>>
>>
>>
>> I found “phosphor-ipmi-flash” have not support flash over eSPI yet.
>>
>> May I ask if you have any plans to support flash over eSPI?
>>
>>
>>
>> I have done a simple test about shared memory between host and BMC :
>>
>> The shared memory is work after I set ESPI084 (source address) and ESPI088 (target address) registers.
>>
>> But it has an limitation that only 256 bytes are available on each page (4KB).
>>
>>
>> For example, if host address starts to write from 0xFE0B0000 (BMC reserved enough memory already)
>>
>> Writable area are:
>>
>> 0xFE0B0000 ~ 0xFE0B00FF
>>
>> 0xFE0B1000 ~ 0xFE0B10FF
>>
>> 0xFE0B2000 ~ 0xFE0B20FF
>>
>> 0xFE0B3000 ~ 0xFE0B30FF
>>
>> …
>>
>> …
>>
>> …
>>
>>
>>
>>
>>
>> Thanks,
>> Harry

Harry, currently there's no plan to implement it as I have no method
of testing it,  However, it should prove fairly straightforward to add
another option to the transport mechanism list.  Please let me know if
you run into any blockers.