mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-11-23 11:35:19 +01:00
95 lines
2.3 KiB
C
95 lines
2.3 KiB
C
/** @file
|
|
|
|
OcRtcLib - library with RTC I/O functions
|
|
|
|
Copyright (c) 2017-2018, vit9696
|
|
|
|
All rights reserved.
|
|
|
|
This program and the accompanying materials
|
|
are licensed and made available under the terms and conditions of the BSD License
|
|
which accompanies this distribution. The full text of the license may be found at
|
|
http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
|
|
**/
|
|
|
|
#ifndef OC_RTC_LIB_H
|
|
#define OC_RTC_LIB_H
|
|
|
|
#include <Protocol/AppleRtcRam.h>
|
|
|
|
//
|
|
// Standard interface, available on most Intel chipsets
|
|
//
|
|
|
|
UINT8
|
|
OcRtcRead (
|
|
IN UINT8 Offset
|
|
);
|
|
|
|
VOID
|
|
OcRtcWrite (
|
|
IN UINT8 Offset,
|
|
IN UINT8 Value
|
|
);
|
|
|
|
/**
|
|
Calculate Apple CMOS checksum.
|
|
This is a modified version of ANSI CRC16 in REFIN mode (0xA001 poly).
|
|
See http://zlib.net/crc_v3.txt for more details.
|
|
|
|
1. Effective poly is 0x2001 due to a bitwise OR with BIT15.
|
|
The change turns CRC16 into CRC14, making BIT14 and BIT15 always zero.
|
|
This modification is commonly found in legacy Phoenix firmwares,
|
|
where it was used for password hashing as found by dogbert:
|
|
http://sites.google.com/site/dogber1/blag/pwgen-5dec.py
|
|
|
|
2. Only 7 shifts per byte are performed instead of the usual 8.
|
|
This might improve checksum quality against specific data, but the exact
|
|
reasons are unknown. The algorithm did not change since its introduction
|
|
in 10.4.x, and since Apple Developer Transition Kit was based on Phoenix
|
|
firmware, this could just be a quick change to get a different checksum.
|
|
|
|
@param[in] Data Pointer to data to calculate the checksum of.
|
|
@param[in] Size Size of data.
|
|
|
|
@retval Resulting checksum.
|
|
**/
|
|
UINT16
|
|
OcRtcChecksumApple (
|
|
IN CONST VOID *Data,
|
|
IN UINTN Size
|
|
);
|
|
|
|
/**
|
|
Install and initialise Apple RTC RAM protocol.
|
|
|
|
@param[in] Reinstall Overwrite installed protocol.
|
|
|
|
@retval installed or located protocol or NULL.
|
|
**/
|
|
APPLE_RTC_RAM_PROTOCOL *
|
|
OcAppleRtcRamInstallProtocol (
|
|
IN BOOLEAN Reinstall
|
|
);
|
|
|
|
//
|
|
// Modern faster interface, available on IvyBridge or newer
|
|
//
|
|
|
|
UINT8
|
|
OcRtcReadIvy (
|
|
IN UINT8 Offset
|
|
);
|
|
|
|
VOID
|
|
OcRtcWriteIvy (
|
|
IN UINT8 Offset,
|
|
IN UINT8 Value
|
|
);
|
|
|
|
#endif // OC_RTC_LIB_H
|