diff --git a/src/mainboard/intel/graysreef/mainboard_smi.c b/src/mainboard/intel/graysreef/mainboard_smi.c
new file mode 100644
index 0000000..ecfc385
--- /dev/null
+++ b/src/mainboard/intel/graysreef/mainboard_smi.c
@@ -0,0 +1,97 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2008-2009 coresystems GmbH
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <arch/io.h>
+#include <arch/romcc_io.h>
+#include <console/console.h>
+#include <cpu/x86/smm.h>
+#include <southbridge/intel/lynxpoint/nvs.h>
+#include <southbridge/intel/lynxpoint/pch.h>
+#include <southbridge/intel/lynxpoint/me.h>
+#include <northbridge/intel/haswell/haswell.h>
+#include <cpu/intel/haswell/haswell.h>
+
+int mainboard_io_trap_handler(int smif)
+{
+	switch (smif) {
+	case 0x99:
+		printk(BIOS_DEBUG, "Sample\n");
+		smm_get_gnvs()->smif = 0;
+		break;
+	default:
+		return 0;
+	}
+
+	/* On success, the IO Trap Handler returns 0
+	 * On failure, the IO Trap Handler returns a value != 0
+	 *
+	 * For now, we force the return value to 0 and log all traps to
+	 * see what's going on.
+	 */
+	//gnvs->smif = 0;
+	return 1;
+}
+
+/*
+ * Change LED_POWER# (SIO GPIO 45) state based on sleep type.
+ * The IO address is hardcoded as we don't have device path in SMM.
+ */
+#define SIO_GPIO_BASE_SET4	(0x730 + 3)
+#define SIO_GPIO_BLINK_GPIO45	0x25
+void mainboard_smi_sleep(u8 slp_typ)
+{
+	u8 reg8;
+
+	switch (slp_typ) {
+	case SLP_TYP_S3:
+	case SLP_TYP_S4:
+		break;
+
+	case SLP_TYP_S5:
+		/* Turn off LED */
+		reg8 = inb(SIO_GPIO_BASE_SET4);
+		reg8 |= (1 << 5);
+		outb(reg8, SIO_GPIO_BASE_SET4);
+		break;
+	}
+}
+
+#define APMC_FINALIZE 0xcb
+
+static int mainboard_finalized = 0;
+
+int mainboard_smi_apmc(u8 apmc)
+{
+	switch (apmc) {
+	case APMC_FINALIZE:
+		if (mainboard_finalized) {
+			printk(BIOS_DEBUG, "SMI#: Already finalized\n");
+			return 0;
+		}
+
+		intel_me_finalize_smm();
+		intel_pch_finalize_smm();
+		intel_northbridge_haswell_finalize_smm();
+		intel_cpu_haswell_finalize_smm();
+
+		mainboard_finalized = 1;
+		break;
+	}
+	return 0;
+}