Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/37935 )
Change subject: src/mainboard/*.asl: Remove _HID / _ADR objects ......................................................................
Patch Set 7:
(1 comment)
https://review.coreboot.org/c/coreboot/+/37935/7//COMMIT_MSG Commit Message:
https://review.coreboot.org/c/coreboot/+/37935/7//COMMIT_MSG@9 PS7, Line 9: A device object must contain either a _HID object or an _ADR object, : but should not contain both.
I understand this change is to be ACPI 6. […]
It's not about 6.3 in particular. I don't know when that rule (to have only one of them) was established, but newer iasl warns about it.
If a bus is enumerated by the OS, like PCI, one is supposed to provide an _ADR so that the device nodes in ACPI can be mapped to the devices the OS discovered. The OS already knows the type of the device and what driver to attach.
If a bus is not enumerated by the OS, existence of the devices is assumed (depending on _STA) and the type is given by _HID.
The devices of the Aopen board are PCI devices, hence _ADR has to be kept. It seems purely cosmetic anyway, as these device nodes contain no information and are not referenced anywhere (I guess one could just remove them).