ACPI Tables
This section has been derived from the Getting Started with ACPI guide. It may be out of date. Please refer to latest documentation when possible.
So what are DSDTs and SSDTs? Well, these are tables present in your firmware that outline hardware devices like USB controllers, CPU threads, embedded controllers, system clocks and such. A DSDT (Differentiated System Description Table) can be seen as the body holding most of the info with smaller bits of info being passed by the SSDT (Secondary System Description Table). You can think of the DSDT as the building blueprints with SSDTs being sticky notes outlining extra details to the project.
So What would we need for a virtual machine?
Mac OS X / macOS can be very picky about the devices present in the DSDT and so our job is to correct it. The main devices that need to be corrected for Darwin to work properly depends on your installation target:
For Catalina (10.15.7) and above, we’ll need:
- Embedded controller (EC)
- Mac OS X / macOS requires a device named EC to be present, so we create a dummy EC. The USBX devices (See next) also require an EC device to work.
- USBX
- This sets the correct USB power properties for charging devices like iPhones.
- Plugin type
- This generally allows the use of XCPM providing native CPU power management on Intel CPUs. Our version will enable VMPlatformPlugin XCPM, exactly like a Parallels VM.
For our use case on MacPro7,1 we will be emulating an Intel Cascade Lake CPU so regardless of the host architecture, the only ACPI’s we require to boot will be SSDT-EC-USBX and SSDT-PLUG.
For Mojave (10.14.4) and older, we’ll need:
- Embedded controller (EC)
- Mac OS X requires a device named EC to be present, so we create a dummy EC.
For our use case on MacPro5,1 / MacPro4,1 and MacPro2,1 we will be emulating an Intel Westmere E56XX CPU, or an Intel Celeron (Conroe/Merom) on older models so regardless of the host architecture, the only ACPI file we require to boot will be SSDT-EC.
Thanks to ExtremeXT for allowing me to include his manually created SSDT-EC-USBX which combines them into a single file, as well as the included SSDT-PLUG file.
Thanks to CorpNewt for SSDTTime, which was used on a DarwinKVM VM booted in to Arch Linux, to dump and create SSDT-EC.
I’ve tested all files and it works as expected, and I use it for my daily machine so I’m confident including it, feel free to manually make your own or possibly try the ones from Acidanthera! As long as you complete this ACPI section for your target installation, you can go ahead to the next step.
It’s been brought to my attention that the EC device is potentially not even required when running in virtualized environments, I haven’t had time to personally confirm that, but wanted to include it in here that this is a real possibility and this page may look very different before 2.0.0 releases fully!