The _ool variations of the IOKit device.defs functions all incorrectly deal with error conditions. If you run the mig tool on device.defs you can see the source of the kernel-side MIG handling code.
The _ool variations of the IOKit device.defs functions all incorrectly deal with error conditions. If you run the mig tool on device.defs you can see the source of the kernel-side MIG handling code.