Stefano,
https://github.com/zephyrproject-rtos/zephyr/tree/main/boards/arm/mps2_an521
The above is the Zephyr board def for a Dual M33 device & board. This is not true exactly but you can think of mps2_an521 as the view from secure world and mps2_an521_ns as the non secure world view.
All the devices in mps2_an521_common.dtsi are avilable at a non-secure side address: 0x4000_0000 + reg and secure side address of 0x5000_0000 + reg
This is the second simple case I mentioned.
It seems to me we should be able to handle this with one *-ranges at the "soc" bus level. This is similar to how they do this at compile time with includes.
Bill
system-dt@lists.openampproject.org