1/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 *   Copyright (C) 1991, 1992 Linus Torvalds
4 *   Copyright 2007 rPath, Inc. - All Rights Reserved
5 *   Copyright 2009 Intel Corporation; author H. Peter Anvin
6 *
7 *   This file is part of the Linux kernel, and is made available under
8 *   the terms of the GNU General Public License version 2.
9 *
10 * ----------------------------------------------------------------------- */
11
12/*
13 * Get the MCA system description table
14 */
15
16#include "boot.h"
17
18int query_mca(void)
19{
20	struct biosregs ireg, oreg;
21	u16 len;
22
23	initregs(&ireg);
24	ireg.ah = 0xc0;
25	intcall(0x15, &ireg, &oreg);
26
27	if (oreg.eflags & X86_EFLAGS_CF)
28		return -1;	/* No MCA present */
29
30	set_fs(oreg.es);
31	len = rdfs16(oreg.bx);
32
33	if (len > sizeof(boot_params.sys_desc_table))
34		len = sizeof(boot_params.sys_desc_table);
35
36	copy_from_fs(&boot_params.sys_desc_table, oreg.bx, len);
37	return 0;
38}
39