This platform copies more files into `/boot` which are necessary to be
able to boot IoT on some single board computers.
We also immediately set this on the `Aarch64_IoT` platform which needs
u-boot to be placed in the `/boot`.
This closes#3312.
Convenience function for creating a map with a single input pointing to
a pipeline's tree with a given key.
Different stages use different keys in the map (often "tree").
Functions will be added for each stage to create a map with the
appropriate key when necessary.
The references field in org.osbuild.tree inputs currently supports one
of three forms, all of which are functionally equivalent:
- Array of one string
- Array of one object with key "id" and string value
- Single object with no properties (only key/name)
We use the first form which is the simplest.
The string should refer to a pipeline by name (as name:<pipelinename>),
which means the input refer to the final tree of the named pipeline.
