Setting up the development environment

First, you would need to replicate the production station. For replicating the station, you can follow the instructions described in: https://github.com/sbtinstruments/wharf.

Then, you are ready to set up the dev environment.

SSH keys

In the current version of wharf (1/12/2023) we have added a feature that when you connect a USB driver to the Raspberry Pi, it will copy the ssh/authorized_keys file (if exists in the USB) to the /home/root/.ssh folder. It is important that you add your public key so you can develop using VScode remote extension.

Set up VScode remote

Add the following configuration to your ~/.ssh/config.

Host <hostname>
    HostName %h
    User root
    PasswordAuthentication no
    ForwardX11 yes
    ForwardAgent yes

Be aware that the <hostname> is set also using the udev service that reads the identification.json file from the USB drive you plug to the Raspberry Pi.

Second, you have to make the rootfs read and write by running the following command:

mount -o rw, remount /

Important
Note that this is done only in the development station. The production station we keep it read only.

Install extensions and set up display

After the previous step is finilized, we connect using the VScode Remote extension and we clone this repository in the Raspberry Pi:

git clone [email protected]:sbtinstruments/wright.git

If you want to forward the display, you will need to run a X11 server from your computer, e.g. VcXsrv on Windows.

Inside the .vscode/ folder, we have created a debugging and extension file. Install all the recommended extensions and then reload the window and the terminal (just to make sure all the changes are applied). Make sure the $DISPLAY environmental variable is set by running:

echo $DISPLAY

Now you should be able to run in debugging mode pressing F5.

Build your wharf-image in Yocto

Once you have commited the changes using the following inline config:

git -c "user.name=<your-name>" -c "user.email=<you-email>" commit -m "<your-commit-message>"

, you will like to create a production image. For that, you copy the commit hash to the file wharfos.conf in the repository https://github.com/sbtinstruments/sbt-yocto.

Then, run the following commands in your Yocto dev container:

cli setup sbt-raspberry
cd build sbt-raspberry
bitbake wharf-image

Once finalized bitbaking, you need to write the image on a SD card. First, you download the image to your local computer:

docker cp <devcontainerID>:/sbt-yocto/build-sbt-raspberry/tmp/deploy/images/sbt-raspberry/wharf-image-sbt-raspberry-<date>.rootfs.wic </path/to/local/folder>

Using the Raspberry Pi imager (download here https://www.raspberrypi.com/software/), write the above rootfs.wic image in the SD card and when is done, plug it into the Raspberry Pi SD card holder. Connect the power supply and your new changes should be applied now.