Now allows applying external overlays either in form of
.dts file, literal dts context added to store or precompiled .dtbo.
If overlays are defined, kernel device-trees are compiled with '-@'
so the .dtb files contain symbols which we can reference in our
overlays.
Since `fdtoverlay` doesn't respect `/ compatible` by itself
we query compatible strings of both `dtb` and `dtbo(verlay)`
and apply only if latter is substring of the former.
Also adds support for filtering .dtb files (as there are now nearly 1k
dtbs).
Co-authored-by: georgewhewell <georgerw@gmail.com>
Co-authored-by: Kai Wohlfahrt <kai.wohlfahrt@gmail.com>
This can be used to explicitly specify a specific dtb file, relative to
the dtb base.
Update the generic-extlinux-compatible module to make use of this option.
Add support for custom device-tree files, and applying overlays to them.
This is useful for supporting non-discoverable hardware, such as sensors
attached to GPIO pins on a Raspberry Pi.
