diff --git a/src/mainboard/starlabs/starbook/cmos.layout b/src/mainboard/starlabs/starbook/cmos.layout
index fa912b5a13..d725d042d0 100644
--- a/src/mainboard/starlabs/starbook/cmos.layout
+++ b/src/mainboard/starlabs/starbook/cmos.layout
@@ -44,6 +44,9 @@ entries
 # coreboot config options: check sums
 984	16	h	0	check_sum
 
+# coreboot config options: ramtop
+1000	10	h	0	ramtop
+
 # Bank: 2
 # embedded controller settings (outside the checksummed area)
 1024	8	h	1	fn_lock_state
diff --git a/src/mainboard/starlabs/starbook/variants/tgl/cmos.layout b/src/mainboard/starlabs/starbook/variants/tgl/cmos.layout
index 1700d0d9c1..589359fa71 100644
--- a/src/mainboard/starlabs/starbook/variants/tgl/cmos.layout
+++ b/src/mainboard/starlabs/starbook/variants/tgl/cmos.layout
@@ -44,6 +44,9 @@ entries
 # coreboot config options: check sums
 984	16	h	0	check_sum
 
+# coreboot config options: ramtop
+1000	10	h	0	ramtop
+
 # Bank: 2
 # embedded controller settings (outside the checksummed area)
 1024	8	h	1	fn_lock_state