Setup for Building for Linkit Smart 7688

Overview

Building for the Linkiit Smart 7688 device requires some one-time setup of your Linux host build enviornment. Once the host environment is configured, building a KinomaJS application is very similar as on the other platforms.

The Linkit Smart 7688 is a MIPS architecture device running the OpenWrt version of Linux. The SDK includes mraa to access the pins on the device.

This document and build instructions are based off of the version 0.9.3 firmware and SDK. Information about creating the boot image and SD card for this configuration can be found on the Linkit Smart 7688 site.

The main steps for setting up your Linux host build environment for the Linkit Smart 7688 are as follows:

1. Download the SDK and toolchain for the platform to build and make the environment for cross-compiling the code.

2. Install additional libraries

3. Set up environment variables.

Download SDK

The Linkit Smart 7688 SDK includes the build tools and sysroot and can be found on the Linkit Smart 7688 website.

Download and unpack the following package somewhere on your host build machine.

• Linux Toolchain

mkdir /opt/tools/linkit7688
cd /opt/tools/linkit7688
tar -jxvf /tmp/OpenWrt-Toolchain-ramips-mt7688_gcc-4.8-linaro_uClibc-0.9.33.2.Linux-x86_64.tar.bz2

To reduce the size of the paths to the toolchain and sysroot, make a link to it.

cd /opt/tools/linkit7688
ln -s OpenWrt-Toolchain-ramips-mt7688_gcc-4.8-linaro_uClibc-0.9.33.2.Linux-x86_64/toolchain-mipsel_24kec+dsp_gcc-4.8-linaro_uClibc-0.9.33.2 linkitToolchain

Install additional libraries

To access the pins on the device with KinomaJS, install mraa.

(from the MediaTek forum)

1. Fetch the libraries and headers

   cd /opt/tools/linkit7688
   wget -O api.tar.gz https://www.dropbox.com/s/qmx73eyrwwh654v/api.tar.gz?dl=0
   tar -zxvf api.tar.gz
   cd api
    wget -O libmraa.a https://www.dropbox.com/s/ihw50mzq63knwil/libmraa.a?dl=0
   

2. Copy the headers and libraries into place and link library versions

   cp -r mraa* /opt/tools/linkit7688/linkitToolchain/usr/include
   cp libmraa* /opt/tools/linkit7688/linkitToolchain/usr/lib
   cd /opt/tools/linkit7688/linkitToolchain/usr/lib
   ln -s libmraa.so.0.8.0 libmraa.so
   ln -s libmraa.so.0.8.0 libmraa.so.0
   

Set up Environment Variables

Create the following file to load the variables needed to build or set the variables in your local environment.

/etc/profile.d/linkit7688.sh:

export LINKIT7688_SYSROOT=/opt/tools/linkit7688/linkitToolchain
export LINKIT7688_GNUEABI=/opt/tools/linkit7688/linkitToolchain

The build environment is now set up. You can proceed with the KinomaJS build instructions to build an application.