Help. My NVMe shows up as External…

Some people (see comments) are having issues with M.2 devices sitting behind a PCI bridge (IOName is pci-bridge) and then IONVMeFamily.kext fails to read the built-in property.

Update: Blog article updated for macOS Sierra DP4 !

The solution so far was to use a (tiny) SSDT (snippet) or add it to any other SSDT and to set the missing built-in property from a _DSM method, but we can also patch a few more bytes in the binary:

AppleNVMeController::InitializePCI()

test       rax, rax
je         0xa711
or         byte [ds:rbx+0x108], 0x10

Let’s just nop the first five bytes so that it looks like this:

nop
nop
nop
nop
nop
or         byte [ds:rbx+0x108], 0x10

In other words. You need Clover to search for the output of:

echo -n '4885c07407808b0801000010'|xxd -r -p|base64

And replace it with the output of:

echo -n '9090909090808b0801000010'|xxd -r -p|base64

Then you take the result and morph it into this:

    <dict>
        <key>Comment</key>
        <string>IONVMeFamily Pike R. Alpha Patch#External</string>
        <key>Disabled</key>
        <false/>
        <key>Name</key>
        <string>IONVMeFamily</string>
        <key>Find</key>
        <data>SIXAdAeAiwgBAAAQ</data>
        <key>Replace</key>
        <data>kJCQkJCAiwgBAAAQ</data>
    </dict>

Add the above lines to KextsToPatch in your Clover config.plist and that should fix it for you.

Edit: Confirmed working on a Gigabyte GA-Z87MX-D3H where a PCIe X4 card with a M.2 is installed in the PCIEX8 slot (Device _SB.PCI0.PEG1@1,1 in the DSDT).

Edit-2: I have since updated the tiny SSDT for this motherboard. Just rename PEG1 to the device that you are using. Like NPE7 for certain hardware 😉

Edit-3: ACPI code from said link (above) added.

        External(_SB.PCI0.PEG1, DeviceObj)

        /* PEG1 is used for my PCIe card with M.2, installed in slot 'PCIEX8' */

        Scope (\_SB.PCI0.PEG1)
        {
            /* Here we inject a new device (SSD0) for the PCIe card with M.2 */

            Device (SSD0)
            {
                Name (_ADR, Zero)  // _ADR: Address
                Name (NVME, One)
                Method (_DSM, 4, NotSerialized)  // _DSM: Device-Specific Method
                {
                    If (LEqual (Arg2, Zero))
                    {
                        Return (Buffer (One)
                        {
                             0x03
                        })
                    }

                    If (LEqual (NVME, One))
                    {
                        Return (Package (0x04)
                        {
                            "use-msi", 
                            One, 
                            "nvme-LPSR-during-S3-S4", 
                            One
                        })
                    }
                    Else
                    {
                        Return (Package (0x06)
                        {
                            "use-msi", 
                            One, 
                            "sata-express-power-off", 
                            One, 
                            "ssd-off-in-S4", 
                            One
                        })
                    }
                }

                Device (PRT0)
                {
                    Name (_ADR, 0xFFFF)  // _ADR: Address
                    Method (_DSM, 4, NotSerialized)  // _DSM: Device-Specific Method
                    {
                        If (LEqual (Arg2, Zero))
                        {
                            Return (Buffer (One)
                            {
                                 0x03
                            })
                        }

                        Return (Package (0x02)
                        {
                            "io-device-location", 
                            Buffer (0x04)
                            {
                                "SSD"
                            }
                        })
                    }
                }
            }
        }