Bug#910727: Overlays cannot be applied to dtbs - missing DTC_FLAGS='-@'

[Heinrich Schuchardt <xypron.glpk@gmx.de>]

Package: linux-source
Version: 4.18+98
Priority: wishlist

Many boards like the Odroid-C2 come with optional add on boards. E.g.
for the Odroid C2 there is an RTC module. The overlays can be applied by
U-Boot using the 'fdt apply' command.

For successful application of device tree overlays the dtb files must be
built with the environment variable DTC_FLAGS='-@'. This flag adds a
__symbols__ section to the dtb file.

Unfortunately the flag '-@' is not set for packages linux-image-arm64
and linux-image-armhf.

Pleae, adjust the build rules.

Best regards

Heinrich Schuchardt