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1 | /* -*- linux-c -*- ------------------------------------------------------- * |
2 | * | |
3 | * Copyright (C) 1991, 1992 Linus Torvalds | |
4 | * Copyright 2007 rPath, Inc. - All Rights Reserved | |
0a706db3 | 5 | * Copyright 2009 Intel Corporation; author H. Peter Anvin |
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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 | /* | |
3b53d304 PA |
13 | * Get the MCA system description table |
14 | */ | |
15 | ||
16 | #include "boot.h" | |
17 | ||
18 | int query_mca(void) | |
19 | { | |
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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) | |
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28 | return -1; /* No MCA present */ |
29 | ||
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30 | set_fs(oreg.es); |
31 | len = rdfs16(oreg.bx); | |
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32 | |
33 | if (len > sizeof(boot_params.sys_desc_table)) | |
34 | len = sizeof(boot_params.sys_desc_table); | |
35 | ||
0a706db3 | 36 | copy_from_fs(&boot_params.sys_desc_table, oreg.bx, len); |
3b53d304 PA |
37 | return 0; |
38 | } |