How to use eSPI between Host and slave BMC in openbmc project

Andrew Jeffery andrew at
Mon May 11 10:13:24 AEST 2020

Hi Felix,

On Sun, 10 May 2020, at 17:57, zhang_cy1989 wrote:
> Dear Andrew Jeffery
> I noticed that you mentioned eSPI in another 
> mail thread.But I can't find some information in openbmc 
> project.    There are some questions about eSPI:
>        1 Are there some solutions to use eSPI interface in openbmc project?
>        2 Whether the Host side needs eSPI controler driver? I can't find any 
> info about eSPI in linux kernel for host os. Is eSPI transparent to the 
> Host side?
>        3 Whether the slave side(Ex BMC/EC) needs slave eSPI 
> driver? I know there are some registers descriptions of eSPI controller 
> in the ast2500 data sheet.         Unfortunately, I don't find slave 
> eSPI driver either.
>        4 which intel products include eSPI 
> feature?
>        5 eSPI interface can transmit io cycle and mem cycle, 
> but in which case or applications eSPI transfer mem cycle?

Unfortunately I'm not well placed to answer your questions - I work on
IBM POWER systems which use LPC rather than eSPI.

Some of the Intel crew will no doubt be more helpful here, I've added
James on Cc to see if he can give you any pointers. Jeremy has also
been poking at eSPI recently, so I've added him as well.



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