summaryrefslogtreecommitdiffstats
path: root/OvmfPkg/PlatformPei/Cmos.c
blob: 9b34e10b17962384f053b2b884f74da227f1a4fe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
/** @file
  PC/AT CMOS access routines

  Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/


#include "Cmos.h"
#include "Library/IoLib.h"

/**
  Reads 8-bits of CMOS data.

  Reads the 8-bits of CMOS data at the location specified by Index.
  The 8-bit read value is returned.

  @param  Index  The CMOS location to read.

  @return The value read.

**/
UINT8
EFIAPI
CmosRead8 (
  IN      UINTN                     Index
  )
{
  IoWrite8 (0x70, (UINT8) Index);
  return IoRead8 (0x71);
}


/**
  Writes 8-bits of CMOS data.

  Writes 8-bits of CMOS data to the location specified by Index
  with the value specified by Value and returns Value.

  @param  Index  The CMOS location to write.
  @param  Value  The value to write to CMOS.

  @return The value written to CMOS.

**/
UINT8
EFIAPI
CmosWrite8 (
  IN      UINTN                     Index,
  IN      UINT8                     Value
  )
{
  IoWrite8 (0x70, (UINT8) Index);
  IoWrite8 (0x71, Value);
  return Value;
}