[avianes]

This is not true.

Most manufacturers take standardized IP and IP-providers provide an appropriate linux drivers. Few manufacturers are willing to develop and maintain their own GIC hardware and GIC driver, most of the time they just take the ARM standard GIC.

The fact that Apple does not provide drivers is a consequence of the Apple business model. And the fact that the ARM ISA does not stipulate a unique GIC is actually a strength. It makes the architecture more versatile and suitable for evolution (maybe Apple found out that the ARM standard GIC is not complete enough for them).

[emptysongglass]

I think that's uncharitable even if I am using superlatives to describe the situation.

We have plenty of examples in the wild. Just look at the state of Pine64 and u-boot, for example. It's a mess of standards.

And what you see as a strength others don't.

[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.