Added generic function for calculating ACPI table checksum

src/core/acpi.c

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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; either version 2 of the
+ * License, or any later version.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <gpxe/acpi.h>
+
+/** @file
+ *
+ * ACPI support functions
+ *
+ */
+
+/**
+ * Fix up ACPI table checksum
+ *
+ * @v acpi		ACPI table header
+ */
+void acpi_fix_checksum ( struct acpi_description_header *acpi ) {
+	unsigned int i = 0;
+	uint8_t sum = 0;
+
+	for ( i = 0 ; i < acpi->length ; i++ ) {
+		sum += *( ( ( uint8_t * ) acpi ) + i );
+	}
+	acpi->checksum -= sum;
+}

src/include/gpxe/acpi.h

@@ -36,4 +36,6 @@ struct acpi_description_header {
 	uint32_t asl_compiler_revision;
 } __attribute__ (( packed ));
 
+extern void acpi_fix_checksum ( struct acpi_description_header *acpi );
+
 #endif /* _GPXE_ACPI_H */