Hey iFabio, I had a similar question today and saw that this is (currently) the topmost Google result. I figured I'd put my findings here to help future visitors. Here's my mini-tutorial:
acpie is a utility that accepts a binary ACPI dump and a path within and will report the offset, if any, where that path occurs. I haven't looked at the repo but I have to imagine this is probably just logic OpenCore already uses internally for things like ACPI patching that's being exposed via this single-purpose utility. In my case, I'd seen the note below while reviewing the documentation and figured I'd give it a try.
Link
Anyway, the syntax of the command is:
acpie.exe -f (filename of a binary ACPI dump) (ACPI path) [optional: occurrence, if none specified will assume the first]
You can see here that my first command failed because I was trying to use the textual tables, not the compiled one. The successful invocation shows the offset within the file where \_SB occurs, so we know that our path exists within ACPI (as it should for \_SB).
In my case I wanted to verify that the path I'd found for my HPET entry was valid. I manually 'walked up' the nested braces within the .dsl file, but wasn't sure if my understanding of the syntax was correct (I'm honestly still a little confused why sometimes it's _SB and other times _SB_, but that's another story...). Anyway, the path I'd found was
\_SB.PCI0.PX40.HPET
and if I enter it...
You can see that I get an offset, so I think I've at least got the proper path in mind. You can also see what happens if you specify a value that couldn't be found (I can assure you that replacing an O for a 0 was totally not a mistake I made and definitely completely intentional ?).
Just to double-check, if I grab a copy of the opcode list, open the .aml and go to decimal offset 9280 (hex 2440), I can see the opcode info combined with the textual name:
82 DEVICE OP
46 ('F', apparently? Maybe this means something different in this context?)
08 NAME_OP
48 H
50 P
45 E
54 T
08 NAME_OP
As mentioned, you can also specify an optional 'occurrence' value after the path, so like in this case if you wanted to find the nth Current Resource Settings value, you can do so (which would be useful for the 'Skip' parameter in the OpenCore configuration file)
Anyway, hope that was helpful.
