Adding another parameter to cmdline.txt


I was wondering if there was a way to add a cmdline.txt option from the Balena cloud dashboard?

We need to add a parameter, which we did on the SD card, but when we upgraded balena it was removed. We want to make sure it is always applied.

Any suggestions?

Thank you :wink:


Can you let us know what parameters you are looking to add to the cmdline.txt?

I need to add spidev.bufsiz=65535

Hi, thanks for your message. We have discussed internally the possibility of allowing customization of kernel command line arguments and agreed that it is not something we want to provide in our product. A solution that I am internally discussing is providing the spidev driver as a module instead of built in so it can be loaded from the application container with the appropriate parameters passed in. Could you please tell us what device type and BalenaOS version you are currently using?

Just realized it鈥檚 a RaspberryPi4 so I have gone ahead and created a feature request for this at Provide spidev as a module so it can be loaded with appropriate parameters 路 Issue #623 路 balena-os/balena-raspberrypi 路 GitHub. We will update the ticket once this is available.

great. would the module be loaded by default? included with os?

Hey @n42 - The idea is that the module will be included with the OS image, but the loading (and passing the appropriate arguments) will probably be left to the application container. Unfortunately, until this is done you will have to keep configuring devices individually. Hope that helps, we鈥檒l work on the request (here - Provide spidev as a module so it can be loaded with appropriate parameters 路 Issue #623 路 balena-os/balena-raspberrypi 路 GitHub) as soon as we are able, and give you a shout once it鈥檚 released. Let us know if you need any additional support at this stage.


Preloading the config.txt is fine for now. It seems to work as long as we don鈥檛 update the balenaos on the device - which we hope to be able to avoid for the most part. We are also looking for a workaround in our software so it would not require the extra config.

If you do make the change - where will we be notified? can you post on this thread so we鈥檒l be notified that we need to add the load the module?

Thank you.


We are tracking the issue now - and we鈥檒l indeed let you know on this thread when it get鈥檚 merged!

I realize this is almost 3 years later, but I also need to add a parameter to cmdline.txt for my system to work: video=HDMI-A-1:800x480M-32@60D. Has there been a way to do this without manually adding it to the mnt/boot host OS?