Apalis TK1, Ubuntu and Black Screen

I know that Ubuntu isn’t a widely used platform within Toradex however, given that I’m trying to get the JetPack with L4T up and running on the Apalis TK1, I’m unsure where else to ask these questions:

I’m now in a position where I have the NVIDIA L4T rootfs with the Toradex TK1 L4T kernel up and running on my Ixora carrier board. Having had previous success with getting Wi-Fi up and running, I’m now in a position where I am unable to recreate this and I shall explain why.

Upon booting the fresh L4T deployment onto the TK1, I notice that when I get to the Ubuntu desktop, Wi-Fi is not available from the networking options - purely ethernet. Upon further inspection of dmesg, I understand why…

dmesg | grep firmware
iwlwifi 0000:01:00.0: request for firmware file 'iwlwifi-7260-7.ucode' failed.

I know that from using the backports, firmware needs to be present in the /lib/firmware folder so therefore installing the linux-firmware should fix things:

sudo apt-get update
sudo apt-get install linux-firmware
sudo reboot

When the system reboots, however, I lose the desktop environment. I’m presented with a black screen. The X server is already active and restarting it makes not a jot of difference.

If I take a copy of the iwlwifi-7260-7.ucode file, uninstall the linux-firmware package but then restore the iwlwifi-7260-7.ucode file back to the /lib/firmware folder and reboot, the desktop is restored to full operation - however, I am still unable to configure the Wi-Fi from the networking utility (device not ready error) and neither can I connect to a network via the terminal. I able able to scan for networks though:

sudo iwlist wlan0 scan

This returns the available networks within our building - all look correct yet I do not seem to be able to connect to any network:

sudo iwconfig wlan0 essid <OUR_SSID> key <OUR_KEY>

No IP address is ever obtained for wlan0

Like I said at the start of the post, I appreciate that Ubuntu is not your focus but I really am unsure where else to ask these questions given the rather unique hardware platform.

As a slight side note to this, I have previously had ROS up and running on the same Ubuntu deployment which had the Wi-Fi working but try as I can, I can now not get any of the ROS packages to install due to unmet dependencies

Whether i have a bad rootfs which is causing these issues, I’m really not sure - I seem to be going round in circles with some things working and then not. Frustrating!

iwconfig works only for connecting to WEP protected networks. For WPA/WPA2 you’ll need to use wpa_supplicant. You can find the example here:
https://wiki.archlinux.org/index.php/WPA_supplicant#Configuration