I have installed Ubuntu 20.04 Server on a Raspberry pi CM4 (not the standard pi, the compute module), but cannot figure out how to enable the wifi. the CM4 has it physically installed and the board's wifi works under raspios (after running through raspi-config and setting it up), but with the ubuntu image provided by ubuntu, i cannot even see wlan0 (or any wifi adapter) when running
ifconfig or
ls /sys/class/neti am only shown that eth0 and lo exist. i have a feeling it must have to do with enabling the correct spi port or wifi parameters in the dto, but cannot find any documentation on it. Anyone else seeing this with the new compute module?
2 Answers
Problem
My student research group had this issue after flashing RPi/CM4 with Ubuntu Server 20.04 LTS; when running ls /sys/class/net and sudo hwinfo --network --short only eth0 and lo exists.
Problem solving
We ran dmesg | grep -i sdio and discovered an error regarding failed to load driver for Wi-Fi chipset (image).
When checking the drivers installed, by running ls /lib/firmware/brcm/ , there were two drivers missing (image):
brcmfmac43455-sdio.txt
brcmfmac43455-sdio.raspberrypi,4-compute-module.txt
Solution
note: be aware of the difference between 43455 and 43456.
- We found the first driver on github:
Just download it in the folder using
sudo wget - For the second driver we did not find anything, however, we compared the the following drivers:
brcmfmac43456-sdio.raspberrypi,4-compute-module.txt
brcmfmac43456-sdio.raspberrypi,4-model-b.txt
and discovered they where identical. Just duplicate the brcmfmac43455-sdio.raspberrypi,4-model-b.txt and rename it to brcmfmac43456-sdio.raspberrypi,4-compute-module.txt.
After reboot Wi-Fi works!
Distro issue?We believe this may be a distro-issue..
I have the same issue with a remote CM4 I am supposed to work on.
But may I suggest you try installing "Ubuntu Iot Core" snap image and via the serial configure select the Wifi interface and see if that works?
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