diff --git a/src/mainboard/google/octopus/variants/phaser/Makefile.inc b/src/mainboard/google/octopus/variants/phaser/Makefile.inc
index d54ed40095..37270eb960 100644
--- a/src/mainboard/google/octopus/variants/phaser/Makefile.inc
+++ b/src/mainboard/google/octopus/variants/phaser/Makefile.inc
@@ -2,3 +2,4 @@ bootblock-y += gpio.c
 
 ramstage-y += variant.c
 ramstage-y += gpio.c
+ramstage-y += mainboard.c
diff --git a/src/mainboard/google/octopus/variants/phaser/mainboard.c b/src/mainboard/google/octopus/variants/phaser/mainboard.c
new file mode 100644
index 0000000000..2d44830661
--- /dev/null
+++ b/src/mainboard/google/octopus/variants/phaser/mainboard.c
@@ -0,0 +1,32 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <boardid.h>
+#include <ec/google/chromeec/ec.h>
+#include <sar.h>
+
+const char *get_wifi_sar_cbfs_filename(void)
+{
+	const char *filename = NULL;
+	uint32_t sku_id;
+
+	if (google_chromeec_cbi_get_sku_id(&sku_id))
+		return NULL;
+
+	if (sku_id == 5)
+		filename = "wifi_sar-laser.hex";
+
+	return filename;
+}