mainboard/intel/galileo: Enable minimal ACPI tables

Enable the minimal ACPI tables.  Initialize the FADT header and provide
an empty DSDT.

Testing on Galileo:
*  Edit the src/mainboard/intel/galileo/Makefile.inc file:
   *  Add "select ADD_FSP_PDAT_FILE"
   *  Add "select ADD_FSP_RAW_BIN"
   *  Add "select ADD_RMU_FILE"
*  Place the FSP.bin file in the location specified by CONFIG_FSP_FILE
*  Place the pdat.bin files in the location specified by
CONFIG_FSP_PDAT_FILE
*  Place the rmu.bin file in the location specified by CONFIG_RMU_FILE
*  Build EDK2 CorebootPayloadPkg/CorebootPayloadPkgIa32.dsc to generate
UEFIPAYLOAD.fd
*  Edit .config file and add the following lines:
   * CONFIG_PAYLOAD_ELF=y
   * CONFIG_PAYLOAD_FILE="path to UEFIPAYLOAD.fd"
*  Testing successful if:
   *  Outputs multiple lines of debug serial text

Change-Id: I2e30c8af2994c9f56d9ba4fe6bc35e133b1d2d6b
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/13759
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/mainboard/intel/galileo/acpi_tables.c b/src/mainboard/intel/galileo/acpi_tables.c
new file mode 100644
index 0000000..543d265
--- /dev/null
+++ b/src/mainboard/intel/galileo/acpi_tables.c
@@ -0,0 +1,38 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Google Inc.
+ * Copyright (C) 2015-2016 Intel Corporation.
+ *
+ * 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 <string.h>
+#include <soc/acpi.h>
+
+void acpi_create_fadt(acpi_fadt_t *fadt, acpi_facs_t *facs, void *dsdt)
+{
+	acpi_header_t *header = &(fadt->header);
+
+	/* Initialize the FADT header */
+	memset((void *) fadt, 0, sizeof(acpi_fadt_t));
+	memcpy(header->signature, "FACP", 4);
+	header->length = sizeof(acpi_fadt_t);
+	header->revision = 5;
+	memcpy(header->oem_id, OEM_ID, 6);
+	memcpy(header->oem_table_id, ACPI_TABLE_CREATOR, 8);
+	memcpy(header->asl_compiler_id, ASLC, 4);
+	header->asl_compiler_revision = 1;
+
+	/* Fill in SoC specific values */
+	acpi_fill_in_fadt(fadt);
+
+	header->checksum = acpi_checksum((void *) fadt, header->length);
+}