Getting SPI to work

[xkcd]

First post, so please be kind.

I’m trying to use the Rock Pi 4B SPI ports for data transfer to some other hardware, preferably using libmraa.

But I’m not even close

Here is what I’ve tried so far:

• Installed https://redirect.armbian.com/region/EU/rockpi-4b/Focal_legacy image
• Modified /boot/armbianEnv.txt to enable SPI and SPI-DEV
• Expected there to be a dev/spi folder, but there is nothing.

Can someone provide a dummies guide on how to proceed?

Thanks.