# Fixing Trackpads: Manual | Getting Started With ACPI

# # Fixing Trackpads: Manual

- Finding the ACPI path
- Edits to the sample SSDT
- Compiling the SSDT
- Wrapping up

## # Finding the ACPI path

Finding the ACPI pathing is quite easy actually, first open your decompiled DSDT you got from Dumping the DSDT and Decompiling and Compiling with either maciASL(if in macOS) or any other text editor if in Windows or Linux(VSCode has an ACPI extension
(opens new window) that can also help).

Next search for `Device (GPI0)`. Should give you a result similar to this:

What we care about from this is the `_STA` method:

    Method (_STA, 0, NotSerialized)
    {
        If ((GPHD == One))
        {
            Return (0x03)
        }

        Return (0x0F)
    }

What we want is for this to always return `0x0F` when booting macOS, so we want to make an SSDT that will return `GPHD == Zero` in macOS.

NOTE that you may have the other way around where GPHD needs to be set as `One` to return `0x0F`. And your device name may also be different, don't throw random SSDTs in thinking it'll work

Here's some more examples:

With this example, we can see that we need both `SBRG` and `GPEN` to return `One`. If only one is present, it'll create some issues so in our SSDT we'll want to have both of them return `One`:

## # Edits to the sample SSDT

Now that we have our ACPI path, lets grab our SSDT and get to work:

- SSDT-GPI0.dsl
  (opens new window)

From the second example, we'll want to set both GPEN and SBRG to `One` to allow it to operate in macOS:

Before:

    If (_OSI ("Darwin"))
    {
        GPEN = One <- Proper variables
    }

Following the example pathing we found, the SSDT should look something like this:

After:

    If (_OSI ("Darwin"))
    {
        GPEN = One <- Change to the right variables
        SBRG = One <- Change to the right variables
    }

## # Compiling the SSDT

With the SSDT done, you're now ready to compile the SSDT!

## # Wrapping up

Once you're done making your SSDT, either head to the next page to finish the rest of the SSDTs or head here if you're ready to wrap up:

- Cleanup