diff --git a/src/northbridge/intel/gm45/acpi.c b/src/northbridge/intel/gm45/acpi.c
new file mode 100644
index 0000000..da9bfa8
--- /dev/null
+++ b/src/northbridge/intel/gm45/acpi.c
@@ -0,0 +1,107 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2007-2009 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 <types.h>
+#include <string.h>
+#include <console/console.h>
+#include <arch/acpi.h>
+#include <arch/acpigen.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include "gm45.h"
+
+unsigned long acpi_fill_mcfg(unsigned long current)
+{
+	device_t dev;
+	u32 pciexbar = 0;
+	u32 pciexbar_reg;
+	int max_buses;
+
+	dev = dev_find_device(0x8086, 0x2a40, 0);
+	if (!dev)
+		return current;
+
+	pciexbar_reg = pci_read_config32(dev, D0F0_PCIEXBAR_LO);
+
+	// MMCFG not supported or not enabled.
+	if (!(pciexbar_reg & (1 << 0)))
+		return current;
+
+	switch ((pciexbar_reg >> 1) & 3) {
+	case 0: // 256MB
+		pciexbar = pciexbar_reg & ((1 << 31)|(1 << 30)|(1 << 29)|(1 << 28));
+		max_buses = 256;
+		break;
+	case 1: // 128M
+		pciexbar = pciexbar_reg & ((1 << 31)|(1 << 30)|(1 << 29)|(1 << 28)|(1 << 27));
+		max_buses = 128;
+		break;
+	case 2: // 64M
+		pciexbar = pciexbar_reg & ((1 << 31)|(1 << 30)|(1 << 29)|(1 << 28)|(1 << 27)|(1 << 26));
+		max_buses = 64;
+		break;
+	default: // RSVD
+		return current;
+	}
+
+	if (!pciexbar)
+		return current;
+
+	current += acpi_create_mcfg_mmconfig((acpi_mcfg_mmconfig_t *) current,
+			pciexbar, 0x0, 0x0, max_buses - 1);
+
+	return current;
+}
+
+unsigned long acpi_fill_dmar(unsigned long current)
+{
+	int me_active = (dev_find_slot(0, PCI_DEVFN(3, 0)) != NULL);
+	int stepping = pci_read_config8(dev_find_slot(0, PCI_DEVFN(0, 0)), PCI_CLASS_REVISION);
+
+	unsigned long tmp = current;
+	current += acpi_create_dmar_drhd(current, 0, 0, IOMMU_BASE1);
+	current += acpi_create_dmar_drhd_ds_pci(current, 0, 0x1b, 0);
+	acpi_dmar_drhd_fixup(tmp, current);
+
+	if (stepping != STEPPING_B2) {
+		tmp = current;
+		current += acpi_create_dmar_drhd(current, 0, 0, IOMMU_BASE2);
+		current += acpi_create_dmar_drhd_ds_pci(current, 0, 0x2, 0);
+		current += acpi_create_dmar_drhd_ds_pci(current, 0, 0x2, 1);
+		acpi_dmar_drhd_fixup(tmp, current);
+	}
+
+	if (me_active) {
+		tmp = current;
+		current += acpi_create_dmar_drhd(current, 0, 0, IOMMU_BASE3);
+		current += acpi_create_dmar_drhd_ds_pci(current, 0, 0x3, 0);
+		current += acpi_create_dmar_drhd_ds_pci(current, 0, 0x3, 1);
+		current += acpi_create_dmar_drhd_ds_pci(current, 0, 0x3, 2);
+		current += acpi_create_dmar_drhd_ds_pci(current, 0, 0x3, 3);
+		acpi_dmar_drhd_fixup(tmp, current);
+	}
+
+	current += acpi_create_dmar_drhd(current, DRHD_INCLUDE_PCI_ALL, 0, IOMMU_BASE4);
+
+	/* TODO: reserve GTT for 0.2.0 and 0.2.1? */
+	return current;
+}