Update config.ign example to 3.3.0

[cringdahl]

Update config.ign example from 2.3.0 to 3.3.0

2.3.0 is a deprecated version, and butane doesn't output anything but 3.x. The existing 2.3.0 example is not a 1-to-1 translation, and will get newbies (like me) confused as to why a 1-to-1 translation doesn't work. (reason: defining OEM in 3.x appears to overwrite it)

How to use

1. Add changed text to config.ign, plus valid SSH key
2. sudo flatcar-install -d ${DISK} -i config.ign -f flatcar_production_image.bin.bz2 -C stable -B arm64-usr -o ''

Testing done

Verified this config.ign resulted in a basic working RPi4 installation.

• Changelog entries added in the respective changelog/ directory (user-facing change, bug fix, security fix, update)
• Inspected CI output for image differences: /boot and /usr size, packages, list files for any missing binaries, kernel modules, config files, kernel modules, etc.

[tormath1]

Thanks a lot for keeping this up-to-date!

I think we can even more simplify things, with Butane/Ignition v3 we can directly use kernelArguments.

Butane looks like this:

variant: flatcar
version: 1.1.0
kernel_arguments:
  should_exist:
    - console=ttyAMA0,115200n8
    - console=tty1
    - flatcar.autologin
    - usbcore.autosuspend=-1

and Ignition:

{
  "ignition": {
    "version": "3.4.0"
  },
  "kernelArguments": {
    "shouldExist": [
      "console=ttyAMA0,115200n8",
      "console=tty1",
      "flatcar.autologin",
      "usbcore.autosuspend=-1"
    ]
  }

What do you think?