diff --git a/tools/dts/odroidc2.dts b/tools/dts/odroidc2.dts
index 0835335dba1..ca4049dd2d8 100644
--- a/tools/dts/odroidc2.dts
+++ b/tools/dts/odroidc2.dts
@@ -22,18 +22,24 @@
 		#size-cells = < 0x02 >;
 		ranges;
 
+		/* 16 MiB reserved for Hardware ROM Firmware */
 		hwrom@0 {
 			reg = < 0x00 0x00 0x00 0x1000000 >;
 			no-map;
 		};
 
-		secmon@10000000 {
+        /* 2 MiB reserved for ARM Trusted Firmware (BL31) */
+        secmon@10000000 {
 			reg = < 0x00 0x10000000 0x00 0x200000 >;
 			no-map;
 		};
 
+        /* 35 MiB reserved for ARM Trusted Firmware
+         *   0x5000000 - 0x5300000: 3 MiB for BL31 (alternate location)
+         *   0x5300000 - 0x7300000: 32 MiB for BL32 (TrustZone OS)
+         */
 		secmon@5000000 {
-			reg = < 0x00 0x5000000 0x00 0x300000 >;
+			reg = < 0x00 0x5000000 0x00 0x2300000 >;
 			no-map;
 		};