Getting-Started-With-ACPI/Universal/ec-fix.md

Fixing Embedded Controller

What we'll be doing is creating a fake Embedded Controller (EC) to satisfy macOS Catalina's EC addiction, and disabling the EC on desktops to prevent panics and crashes.

You'll want to begin by grabbing either one of these uncompiled SSDT files:

• SSDT-EC-USBX
  • For Skylake and newer and all AMD systems
• SSDT-EC
  • For Broadwell and older

Fixing the Path

For Intel systems, the path is likely correct, though it's worth double checking. You will want to find your current EC by opening your decompiled DSDT and searching for PNP0C09. You should get a result similar to this:

Note: If your EC device happens to already be named EC in your DSDT, you do not need SSDT-EC at all and can move on.

As you can see, PNP0C09 is found under the EC0 device and _SB.PC00.LPC0 scope. Looking at the SSDT though, this differs from the path _SB_.PCI0.LPCB seen within. This will need to be corrected in the SSDT to match what is found in the DSDT. Using the above image, you should get something similar to this:

Scope (\_SB.PC00.LPC0) <- Rename this
{
    Device (EC) <- DO NOT RENAME THIS
    {
        Name (_HID, "ACID0001")  // _HID: Hardware ID
        Method (_STA, 0, NotSerialized)  // _STA: Status
        {
            If (_OSI ("Darwin"))
            {
                Return (0x0F) // Enable our Fake EC only when in macOS
            }
            Else
            {
                Return (Zero)
            }
        }
    }
}

Generally, PC00.LPC0 is most common on Intel HEDT while PCI0.SBRG is most common on AMD. Always verify your path and device. DO NOT ASSUME. If you are having issues finding the Scope, you can use the below Hardware IDs or Addresses:

• Finding the LowPinCount path:
  • Intel: Search Name (_ADR, 0x001F0000)
  • AMD: Search Name (_ADR, 0x00140003)
• Finding the PCI path:
  • Intel: Search PNP0A08 (If multiple show up, use the first one)
  • AMD: Assume PCI0(most AMD DSDTs don't declare the PCI path directly)

Make sure that you do not rename Device (EC). This is what macOS Catalina looks for to boot!

Desktop users, continue down below to disabling your actual EC

Disabling real EC (Desktops only)

For desktops, it's preferable to disable the actual Embedded Controller as it is not supported by macOS 100% and is known to sometimes cause panics. If we use the screenshot above, we'll see that the device name is EC0. Other common names for ECs are H_EC, ECDV, and EC0. You'll want to grab your SSDT again and uncomment the _STA method to disable it (remove the /* and */ around it):

/* <- REMOVE THIS
External (_SB_.PCI0.LPCB.EC0, DeviceObj) <- Rename this

   Scope (\_SB.PCI0.LPCB.EC0) <- Rename this
   {
      Method (_STA, 0, NotSerialized) // _STA: Status
      {
         If (_OSI ("Darwin")) // Darwin = macOS
         {
            Return (0) // Hides our real EC only when in macOS
         }
         Else
      {
      Return (0x0F)
     }
  }
}
*/ <- REMOVE THIS

Like above, make sure the path is correct for the External and Scope field.

What happens if device in the DSDT is already named EC

For laptops, you don't need SSDT-EC at all.

What happens if multiple PNP0C09 show up

When this happens you need to figure out which is the main and which is not, it's fairly easy to figure out. Check each controller for the following properties:

• _HID (Hardware ID)
• _CRS (Current Resource Settings)
• _GPE (General Purpose Events)

Note if you have an STA Method as well, see below: STA Edge Case

What happens if no PNP0C09 show up

This means you only need to fake an Embedded Controller rather so that AppleBusPowerController will load and handle USB power properly and continue booting. To make the actual SSDT, its almost plug and play as no uncommenting needed. The main thing that needs to be changed:

• LowPinCount path
• PCI path

We want to make sure the SSDT hooks into our DSDT correctly so we need to make sure the ACPI path is correct:

• Finding the LowPinCount path:
  • Intel: Search Name (_ADR, 0x001F0000)
  • AMD: Search Name (_ADR, 0x00140003)
• Finding the PCI path:
  • Intel: Search PNP0A08 (If multiple show up, use the first one)
  • AMD: Assume PCI0(most AMD DSDTs don't declare the PCI path directly)

Once you find out, change PCI0.LPCB to your correct path:

Scope (\_SB.PC00.LPC0) <- Rename this
{
    Device (EC) <- DO NOT RENAME THIS
    {
        Name (_HID, "ACID0001")  // _HID: Hardware ID
        Method (_STA, 0, NotSerialized)  // _STA: Status
        {
            If (_OSI ("Darwin"))
            {
                Return (0x0F) // Enable our Fake EC only when in macOS
            }
            Else
            {
                Return (Zero)
            }
        }
    }
}

For those having issues, you can also check Device Manager -> CPU -> BIOS device Name. Windows will only report the main EC so will save you some headache on that

STA Edge Case

Do note that if your PNP0C09 device has a Method (_STA already you can skip down to "What happens if no PNP0C09 show up?". The reason for this is that the real EC is considered disabled already.

Correcting USB Power

Hey what about USBX? Do I need to do anything?

USBX is universal across all systems, it just creates a USBX device that forces USB power properties. This is crucial for fixing Mics, DACs, Webcams, Bluetooth Dongles and other high power draw devices. This is not mandatory to boot but should be added in post-install if not before. Note that it requires the EC functioning correctly and that USBX is only used on skylake+ systems - those on Broadwell and older can ignore.

Now you're ready to compile the SSDT!