1 files changed, 38 insertions, 0 deletions
diff --git a/kernel/arch/x86/boot/mca.c b/kernel/arch/x86/boot/mca.c
new file mode 100644
index 000000000..a95a53114
--- /dev/null
+++ b/kernel/arch/x86/boot/mca.c
@@ -0,0 +1,38 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ *   This file is part of the Linux kernel, and is made available under
+ *   the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Get the MCA system description table
+ */
+
+#include "boot.h"
+
+int query_mca(void)
+{
+	struct biosregs ireg, oreg;
+	u16 len;
+
+	initregs(&ireg);
+	ireg.ah = 0xc0;
+	intcall(0x15, &ireg, &oreg);
+
+	if (oreg.eflags & X86_EFLAGS_CF)
+		return -1;	/* No MCA present */
+
+	set_fs(oreg.es);
+	len = rdfs16(oreg.bx);
+
+	if (len > sizeof(boot_params.sys_desc_table))
+		len = sizeof(boot_params.sys_desc_table);
+
+	copy_from_fs(&boot_params.sys_desc_table, oreg.bx, len);
+	return 0;
+}