Precisely. Since there's no equivalent of the Power ISA in "x86 land", it's hard to make a direct comparison (I don't believe that formally Intel or AMD consider themselves to share an architecture, and they both have slightly different instruction sets), but the closest comparison would be if AMD or Intel released the source code for PSP or ME respectively, along with all other ancillary firmware and documentation for the bring-up procedures so that, without an NDA or business agreement, a third party could design a motherboard around a Threadripper or Xeon CPU, provide that to a customer, and allow the customer to make modifications to the firmware running on that motherboard.
