ec/google/wilco: Details on EC firmware

[Paul Menzel]

Dear coreboot folks,

Some Google Chromebooks come with a Google Wilco EC (EC_GOOGLE_WILCO) 
instead of Google Chrome EC. coreboot implements the interface for the 
Google Wilco EC.

Unfortunately, I was unable to find more details on the firmware. 
Phoronix claims is “open-source firmware” [1].

It’d be great if somebody could provide some details.

Kind regards,

Paul

[1]: 
https://www.phoronix.com/scan.php?page=news_item&px=ChromeOS-Wilco-EC-Li...

[Duncan Laurie]

On Tue, May 25, 2021 at 4:57 AM Paul Menzel  wrote:
> Dear coreboot folks,
>
> Some Google Chromebooks come with a Google Wilco EC (EC_GOOGLE_WILCO)
> instead of Google Chrome EC. coreboot implements the interface for the
> Google Wilco EC.
>
> Unfortunately, I was unable to find more details on the firmware.
> Phoronix claims is “open-source firmware” [1].
>
> It’d be great if somebody could provide some details.

The Wilco EC firmware is a modified version of Dell's typical Latitude EC
that implements a custom mailbox protocol similar to the one we use in the
Chromium EC.

This particular EC firmware is not open source unfortunately, just the
host-side interfaces (kernel and firmware drivers).

-duncan