Zotac ION example:

                Device (IGPU)
                {
                    Name (_ADR, Zero)
                    Method (_DSM, 4, NotSerialized)
                    {
                        Store (Package ()
                            {
                                "@0,can,hot-plug", Buffer (Zero) {},
                                "@0,compatible", Buffer () {"NVDA,NVMac"},
                                "@0,device_type", Buffer () {"display"},
                                "@0,audio-codec-index", Buffer () {0x03, 0x00, 0x00, 0x00},
                                "@0,NVDA,UnderscanMin", Buffer () {0x55, 0x00, 0x00, 0x00},
                                "@0,name", Buffer () {"NVDA,Display-A"},
                                "@1,AAPL,boot-display", Buffer (Zero) {},
                                "@1,can,hot-plug", Buffer (Zero) {},
                                "@1,compatible", Buffer () {"NVDA,NVMac"},
                                "@1,device_type", Buffer () {"display"},
                                "@1,name", Buffer () {"NVDA,Display-B"},
                                "@1,NVDA,UnderscanMin", Buffer () {0x55, 0x00, 0x00, 0x00},
                                "graphic-options", Buffer () {0x04, 0x00, 0x00, 0x00},
                                "hda-gfx", Buffer () {"onboard-1"},
                                "AAPL,aux-power-connected", Buffer () {0x01, 0x00, 0x00, 0x00},
                                "AAPL,backlight-control", Buffer () {0x00, 0x00, 0x00, 0x00},
                                "AAPL00,blackscreen-preferences", Buffer () {0x00, 0x00, 0x00, 0x08},
                                "AAPL01,blackscreen-preferences", Buffer () {0x00, 0x00, 0x00, 0x08},
                                "AAPL01,Coherency", Buffer () {0x02, 0x00, 0x00, 0x00},
                                "device-id", Buffer () {0x61, 0x08, 0x00, 0x00},
                                "device_type", Buffer () {"NVDA,Parent"},
                                "model", Buffer () {"NVIDIA GeForce 9400"},
                                "NVCAP", Buffer () {0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x0C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0B, 0x00, 0x00, 0x00, 0x00},
                                "NVDA,Features", Buffer () {0xFF, 0x06, 0xAE, 0x00},
                                "rom-revision", Buffer () {0x33, 0x33, 0x36, 0x32},
                                "subsystem-id", Buffer () {0xAE, 0x00, 0x00, 0x00},
                                "VRAM,totalsize", Buffer () {0x00, 0x00, 0x00, 0x20}
                            }, Local0)
                        DTGP (Arg0, Arg1, Arg2, Arg3, RefOf (Local0))
                        Return (Local0)
                    }
                }

....................

            Device (HDEF)
            {
                Name (_ADR, 0x00080000)
                Method (_DSM, 4, NotSerialized)
                {
                    Store (Package ()
                        {
                            "layout-id", Buffer () {0x0C, 0x00, 0x00, 0x00},
                            "hda-gfx", Buffer () {"onboard-1"},
                            "PinConfigurations", Buffer (Zero) {}
                        }, Local0)
                    DTGP (Arg0, Arg1, Arg2, Arg3, RefOf (Local0))
                    Return (Local0)
                }
            }