Google Kukui EC

Overview

Kukui is a reference board for Chromium OS-based devices Krane and Kodama. These are known as the Lenovo Chromebook Duet and 10e Chromebook Tablet, respectively.

Zephyr has support for the STM32-based embedded controller (EC) on-board.

Hardware

STM32F098RCH6
MT6370 battery charger
BMM150 compass
BMM160 gyroscope
Connections to the MediaTek AP

Supported Features

The following features are supported:

Interface	Controller	Driver/Component
NVIC	on-chip	nested vector interrupt controller
UART	on-chip	serial port-polling; serial port-interrupt
PINMUX	on-chip	pinmux
GPIO	on-chip	gpio
CLOCK	on-chip	reset and clock control
FLASH	on-chip	flash memory
WATCHDOG	on-chip	independent watchdog

Other features (such as I2C) are not available in Zephyr.

The default configuration can be found in boards/google/kukui/google_kukui_defconfig

Connections and IOs

Each of the GPIO pins can be configured by software as output (push-pull or open-drain), as input (with or without pull-up or pull-down), or as peripheral alternate function.

Default Zephyr Peripheral Mapping:

UART_1 TX/RX : PA10/PA9
I2C_1 SCL/SDA : PB8/PB9
I2C_2 SCL/SDA : PA11/PA12
Volume down : GPIOB pin 11
Volume up : GPIOB pin 10
Power : GPIOA pin 0

Programming and Debugging

Build application as usual for the google_kukui board, and flash using Servo V2, μServo, or Servo V4 (CCD). See the Chromium EC Flashing Documentation [1] for more information.

Debugging

Use SWD with a J-Link or ST-Link.