To upgrade your kernel first download the shell script for the kernel version you require and after making it executable (enter 'chmod 755 <script>') you can install it as 'root' (by entering 'sudo <script>'). Once the script has finished executing the device will need to be rebooted to use the updated (patched) kernel.
4.9.0-11.12 (current latest Zesty kernel)
To get audio running on a Mini PC with a headphone jack using the RT5640 codec (for example Tronsmart Ara) after using a kernel upgrade script simply:
- Open the URL https://github.com/plbossart/UCM in a browser
- Click the green coloured 'Clone or Download' button on the right and download as a 'zip' file
- In a terminal window go to the download directory and enter 'unzip UCM-master.zip'
- Install by entering 'sudo cp -rf UCM-master/bytcr-rt5640 /usr/share/alsa/ucm'