How to build raw disk images for Raspberry Pi

This guide will show how we can build a raw disk image that can be written to an SD-card and booted without any other installation media.

caution

Any data on the SD-card will be erased, please only use a SD-card without anything important on it.

The SD-card must be reasonably large (32 GB or more) and fast (!!).

SeedImage resource

apiVersion: elemental.cattle.io/v1beta1
kind: SeedImage
metadata:
  name: fire-img
  namespace: fleet-default
spec:
  type: raw
  baseImage: registry.opensuse.org/isv/rancher/elemental/dev/containers/suse/sle-micro/5.5:latest
  targetPlatform: linux/arm64
  registrationRef:
    apiVersion: elemental.cattle.io/v1beta1
    kind: MachineRegistration
    name: fire-nodes
    namespace: fleet-default

Check the logs for the build pod using:

kubectl logs -n fleet-default fire-img -f -c build

When the build is finished we can download the image file using wget:

wget --no-check-certificate $(kubectl get seedimage -n fleet-default fire-img -o jsonpath="{.status.downloadURL}") -O sle-micro.arm64.raw

Now we can write the .raw image to the SD-card. This can be done with dd on the Linux command line if you're comfortable with this command. openSUSE has nice instructions on how to write an image to a storage medium for Linux, Windows, and OS X.