Re: [coreboot] Embedded Controller (EC)

[Аладышев Константин]

Thanks! But my main purpose right now is to make standard OS-battery interface through ACPI embedded controller. And as I understand embedded controller in 'twinkie' isn't the one suitable for this case, as 'twinkie' is separate board that implements USB-PD sniffing dongle with Type-C connectors .

Best Regards,
Aladyshev Konstantin

-----Original Message-----
From: [e-mail] [mailto:[e-mail]] On Behalf Of Shawn N
Sent: Friday, December 08, 2017 8:14 PM
To: Аладышев Константин
Cc: Vadim Bendebury; Randall Spangler; Coreboot
Subject: Re: [coreboot] Embedded Controller (EC)

On Fri, Dec 8, 2017 at 8:30 AM, Randall Spangler  wrote:
> On Fri, Dec 8, 2017 at 5:57 AM, Аладышев Константин 
>
> wrote:
> > Thanks for your answer!
> >
> > I've looked more closely at Chromium Embedded Controller project and 
> > EC chips it supports. To my surprise 'chromeec' even supports 
> > ordinary STM32 controllers without ACPI EC registers (am I right?).
>
> Yes, we've used it for everything from the main EC to a USB-PD 
> controller to a charger.  STM32 isn't suitable as the main EC for 
> x86-based Chromebooks, of course, due to lack of eSPI / LPC.
> > So I think is it very important to do schematics as it is in 
> > Chromebooks to make use of this project.
> >
> > Is there any chance to find schematics for Chromebook boards, to get 
> > reference design of implementing ECs with ‘chromeec’ project?
>
> I don't know.  But it supports several STM32 discovery boards, so you 
> can tinker with it on ready-built hardware.

There are also schematics available for several misc. peripherals that use stm32 + cros_ec, see twinkie for example:

https://www.chromium.org/chromium-os/twinkie

Unfortunately there are no schematics for actual Chromebook mainboards publicly available. I looked into making some public, but there were some overriding concerns.
> > Best regards,
> > Aladyshev Konstantin
> >
> > From: [e-mail] [mailto:[e-mail]] On Behalf Of 
> > Randall Spangler
> > Sent: Friday, December 01, 2017 7:02 PM
> > To: Vadim Bendebury
> > Cc: Аладышев Константин; Coreboot; Shawn N
> > Subject: Re: [coreboot] Embedded Controller (EC)
> >
> > On Fri, Dec 1, 2017 at 6:32 AM, Vadim Bendebury 
> >
> > wrote:
> > [+cc a couple of guys who might have some advice in this respect]
> >
> > On Fri, Dec 1, 2017 at 5:07 AM, Аладышев Константин 
> >
> > wrote:
> > Hello! I'm trying to understand, what is the easiest way today to 
> > integrate EC to custom motherboard? What controller should I choose 
> > for new custom motherboard?
> > First of all, are there any ECs on market that ship with embedded
> >
> > firmware, where all you need to do is just a little bit of register 
> > configuration (like SuperIO)? Or is it always like you need to write 
> > all firmware by yourself?
> >
> > Most EC vendors that sell dedicated ECs also sell their SDK and 
> > source code, but it's not cheap.  So usually roll your own, hopefully 
> > based on an open design.
> >
> > In that case what is the main difference between ordinary 
> > microcontroller (for example STM32) and some controller marked by 
> > vendor as EC?
> >
> > Interfaces.  EC will have:
> > • Keyboard scanner
> > • eSPI / LPC for connecting to x86 SoC • More I2C ports (and in the 
> > old days, PECI and PS/2 ports).
> > How stable and flexible are projects about open EC firmware? Is it
> >
> > possible to adapt these projects for my custom motherboard?
> >
> > I'm talking about:
> > Chromium Embedded Controller:
> >
> > http://www.chromium.org/chromium-os/ec-development
> >
> > This is used on all current Chromebooks, so it's full-featured and stable.
> > We do tend to branch old boards, so if your motherboard has an old 
> > chipset on it you may need to look back in time to find support for it.
> > Origami-EC:
> >
> > https://git.code.paulk.fr/gitweb/?p=origami-ec.git;a=summary
> > What is the current status of EC support from coreboot point of view?
> >
> > https://review.coreboot.org/cgit/coreboot.git/tree/src/ec
> >
> > Best regards,
> > Aladyshev Konstantin