Michael Niewöhner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/34948 )
Change subject: superio/nuvoton: add a driver for nct668xd ......................................................................
Patch Set 8:
Patch Set 8:
IIRC one of the boards I had on my desk had some Nuvoton SIO with an external SPI flash; probably for firmware. I can have a look tomorrow and if I still have it, it has one of those SIOs and I find some cardboard box it fits into, I could send it to you if you want to port it.
Had a look and didn't find that board any more, so I guess it was the broken ivy bridge board I threw away a few months ago.
ooops.... I'm sorry, I didn't check this CR for a month... :S
Well, yes, there are at least Lenovo P320, M800/900 and there was another one but I forgot the model... There are some Intel boards, too.
Those newer Nuvoton eSIOs have a SPI flash with EC firmware on it, that can be customized by OEM.