In a previous post I explained how to use a Solomon SSD1306 OLED display on Fedora with a Raspberry Pi, but that only covered displays that come with a I2C driving interface.

The SSD1306 display controller also supports a (both 3-wire and 4-wire) SPI interface, and the ssd130x DRM driver has support for it since Linux 5.19.

This blog post explains how to setup Fedora to use a SSD1306 OLED when connected through 4-wire SPI interface.

First you need connect the SSD1306 display to the RPi, there are different ways to do this since one can choose the GPIO to use for some the reset and data/command pins.

But to simplify the configuration, one could use the default GPIO pins that are defined in the ssd1306-spi.dtbo provided by the RPi firmware package.

To do this, connect the SSD1306 display to the RPi as follows:

Then you need to install Fedora, this can be done by downloading an aarch64 Fedora raw image (e.g: Workstation Edition) and executing the following command:

sudo arm-image-installer --image $image --target=rpi4 -- \\
media=$device --addconsole --addkey=id_rsa.pub \\
--norootpass --resizefs

where $device is the block device for your uSD (e.g: /dev/sda) and image is the file name (e.g: Fedora-Workstation-40-1.14.aarch64.raw.xz) of the downloaded image.

Finally you need to configure the RPi firmware to enable the SPI pins and load the ssd1306-spi Device Tree Blob Overlay (dtbo) to register a SSD1306 SPI device, e.g:

sudo cat << EOF >> /boot/efi/config.txt
dtparam=spi=on
dtoverlay=ssd1306-spi,inverted
EOF

The ssd1306-spi.dtbo supports many parameters in case your display doesn’t match the defaults. Take a look to the RPi overlays README for more details about all these parameters and their possible values.

The ssd130x DRM driver registers an emulated fbdev device that can be bound with fbcon and use the OLED display to have a framebuffer console. If you want to do that, it’s convenient to change the virtual terminal console font to a smaller one, e.g:

sudo sed -i 's/FONT=.*/FONT="drdos8x8"/' /etc/vconsole.conf
sudo dracut -f

And that’s it. Happy hacking!