diff --git a/src/mainboard/google/brox/variants/lotso/Makefile.mk b/src/mainboard/google/brox/variants/lotso/Makefile.mk
index 4868317..849eb1a 100644
--- a/src/mainboard/google/brox/variants/lotso/Makefile.mk
+++ b/src/mainboard/google/brox/variants/lotso/Makefile.mk
@@ -3,4 +3,5 @@
 bootblock-y += gpio.c
 romstage-y += memory.c
 romstage-y += gpio.c
+ramstage-$(CONFIG_FW_CONFIG) += variant.c
 ramstage-y += gpio.c
diff --git a/src/mainboard/google/brox/variants/lotso/variant.c b/src/mainboard/google/brox/variants/lotso/variant.c
new file mode 100644
index 0000000..72b7cbe
--- /dev/null
+++ b/src/mainboard/google/brox/variants/lotso/variant.c
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <assert.h>
+#include <baseboard/variants.h>
+#include <chip.h>
+#include <fw_config.h>
+#include <sar.h>
+
+void variant_update_soc_chip_config(struct soc_intel_alderlake_config *config)
+{
+	if (fw_config_probe(FW_CONFIG(WIFI_BT, WIFI_CNVI_WIFI6E))) {
+		printk(BIOS_INFO, "CNVi bluetooth enabled by fw_config\n");
+		config->cnvi_bt_core = true;
+	}
+}
+
+const char *get_wifi_sar_cbfs_filename(void)
+{
+	return get_wifi_sar_fw_config_filename(FW_CONFIG_FIELD(WIFI_BT));
+}