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 the defconfig file: boards/arm/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.