diff --git a/src/mainboard/amd/dbm690t/devicetree.cb b/src/mainboard/amd/dbm690t/devicetree.cb
index d873681351..870503789f 100644
--- a/src/mainboard/amd/dbm690t/devicetree.cb
+++ b/src/mainboard/amd/dbm690t/devicetree.cb
@@ -1,3 +1,14 @@
+#Define gpp_configuration,	A=0, B=1, C=2, D=3, E=4(default)
+#Define vga_rom_address = 0xfff0000
+#Define port_enable, (bit map): GFX(2,3), GPP(4,5,6,7)
+#Define gfx_dev2_dev3, 0: a link will never be established on Dev2 or Dev3,
+#			1: the system allows a PCIE link to be established on Dev2 or Dev3.
+#Define gfx_dual_slot, 0: single slot, 1: dual slot
+#Define gfx_lane_reversal, 0: disable lane reversal, 1: enable
+#Define gfx_tmds, 0: didn't support TMDS, 1: support
+#Define gfx_compliance, 0: didn't support compliance, 1: support
+#Define gfx_reconfiguration, 0: short reconfiguration, 1(default): long reconfiguration
+#Define gfx_link_width, 0: x16, 1: x1, 2: x2, 3: x4, 4: x8, 5: x12 (not supported), 6: x16
 chip northbridge/amd/amdk8/root_complex
 	device apic_cluster 0 on
 		chip cpu/amd/socket_S1G1