[avianes]

Pine64 is based on an Allwinner A64 which has a ARM GIC-400. ARM GIC-400 is a standard GIC IP from ARM and compliant with ARM GICv2 specification.

It seems pretty standard to me, not a custom GIC as Apple.

And yes, in u-boot there are plenty of device-trees for each target. What's wrong with that?

The device tree is usually provided by the manufacturer, the compiled device tree is usually very small and allows genericity.