Cross-compiling

By using Golang tools the Mender client can easily be cross-compiled to target a number of different architectures.

The Mender client must also be integrated with your board, cross-compiling it is often one step in the board integration process.

This example is targeting the armhf architecture but is applicable to other architectures with minor adjustments.

Prerequisites

A Golang environment

Follow the instructions in the official Golang page to create a working Golang environment.

A cross-compiler toolchain

You will need a cross-compiler toolchain target ting your device. If you are using Ubuntu and target ting armhf, install it with:

sudo apt install gcc-arm-linux-gnueabihf

Compile the Mender client

First, fetch the Mender client source code:

go get github.com/mendersoftware/mender

Change directory to where the Mender sources are:

cd $GOPATH/src/github.com/mendersoftware/mender

Check out the version of the Mender client you want to compile; see git tag for available versions. For example, to use Mender 1.7.0 run the following command:

git checkout 1.7.0

Then cross-compile the mender binary with:

env CGO_ENABLED=1 \
    CC=arm-linux-gnueabihf-gcc \
    GOOS=linux \
    GOARCH=arm make build

After compilation has finished, the Mender binary is located at:

$GOPATH/src/github.com/mendersoftware/mender/mender

The strip command for your toolchain can be used to reduce the size of the binary by removing symbols that are not needed on a production system. In our example, we can run arm-linux-gnueabihf-strip mender.