Build a QEMU/VirtualBox image
HERE OTA Connect lets you easily manage OTA updates to embedded devices running custom-built Yocto images. This is a guide for building a simple Yocto image that you can run in Virtualbox or QEMU. This is a good way to get started if you don’t know yet what hardware your project will use, or if you just want to try out the features of HERE OTA Connect without worrying about physical devices.
You’ll need a build machine with the following:
A x86-64 Linux distro supported by the Yocto project with the required packages installed. (On a Debian-based system, you should be able to install all the required packages with
sudo apt-get install gawk wget git-core diffstat unzip texinfo gcc-multilib default-jre build-essential chrpath parted socat libsdl1.2-dev xterm repo libpython2.7-dev.)
Many/most distros that aren’t on the officially supported list will still work just fine—feel free to give it a try with whatever you’re running.
Although the Yocto project as a whole does support architectures other than x86-64 for the build machine, one of the layers we’ll be using only supports x86-64.
You can run this all inside a VM, but a Yocto build is a pretty resource-intensive process, so generally we don’t recommend it. If you do, make sure there’s plenty of ram and disk space available to the VM.
100GB of free disk space
Download the latest version directly from Google, or
install it from your distro’s packages if available (
apt-get install repo)
Also, make sure that you’ve generated your provisioning credentials first.
Create your Yocto build environment
First, clone a manifest file for the quickstart project:
mkdir myproject cd myproject repo init -u https://github.com/advancedtelematic/updater-repo.git repo sync
This downloads the basic Yocto layers you need.
Now you can run the following script to get the environment set up:
source meta-updater/scripts/envsetup.sh qemux86-64
Customize your build
The environment setup script will have created a build directory and placed you in it. It also generates a configuration file, located at
conf/local.conf. This file is where we’ll make our modifications to the base config.
To connect with your HERE OTA Connect account, you’ll need the provisioning credentials bundle you downloaded earlier. Add the following line to your local.conf to supply those credentials to the build:
SOTA_PACKED_CREDENTIALS = "/path/to/your/credentials.zip"
Optional configuration keys
Set image name
When you build a filesystem image, it gets automatically uploaded to OTA Connect. By default, the image will be named
qemux86-64-ota, and you’ll see the various versions of the image under that name. You can also choose to set your own name as follows:
OSTREE_BRANCHNAME = "my-super-great-project"
Persistent Yocto shared state cache and download directory
Yocto caches its build artefacts to speed up future builds. By default, these are stored under the build directory of the current project. However, if you’re planning to build several different projects that have some shared base files, you might want them to share their cache directories, both to save space and speed up your builds. You can do that as follows:
SSTATE_DIR = "/path/to/your/shared-sstate" DL_DIR = "/path/to/your/shared-download"
Add extra packages
There are quite a lot of packages available to install that aren’t installed by default. You can add extra packages to your image with IMAGE_INSTALL_append; for example, this will install vim:
IMAGE_INSTALL_append = " vim " (1)
|1||Note the spaces before and after the package name. This option dumbly appends a string to an install list, so we wrap it in spaces to make sure we don’t alter the list in unexpected ways.|
You can get a list of all the available packages in the layers you have configured with
Now you’re ready to build an image.
This step will take a while. If you used the build mirror, it might be as little as 10-15 minutes. Building everything from scratch, it will likely take a few hours.
Run the built image with QEMU
The build process creates disk images as an artefact. You can then directly run them with QEMU. (If you don’t already have it installed, install it with
apt-get install qemu or similar.) The meta-updater layer contains a helper script to launch the images:
../meta-updater/scripts/run-qemu-ota [image name] [mac address]
Both arguments are optional; image name defaults to
core-image-minimal, and if a mac address isn’t specified, a random one is generated.
You should see your new device appear in OTA Connect shortly after it boots. It will generate a random name for itself during autoprovisioning; you can change the name later.