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1 | /** @file\r |
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2 | This file implements CalculateCrc32 Boot Services as defined in\r |
3 | Platform Initialization specification 1.0 VOLUME 2 DXE Core Interface.\r |
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4 | \r |
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5 | This Boot Services is in the Runtime Driver because this service is\r |
6 | also required by SetVirtualAddressMap() when the EFI System Table and\r |
7 | EFI Runtime Services Table are converted from physical address to\r |
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8 | virtual addresses. This requires that the 32-bit CRC be recomputed.\r |
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9 | \r |
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10 | Copyright (c) 2006 - 2008, Intel Corporation. <BR>\r |
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11 | All rights reserved. This program and the accompanying materials\r |
12 | are licensed and made available under the terms and conditions of the BSD License\r |
13 | which accompanies this distribution. The full text of the license may be found at\r |
14 | http://opensource.org/licenses/bsd-license.php\r |
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15 | \r |
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16 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
17 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r |
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18 | \r |
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19 | **/\r |
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20 | \r |
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21 | \r |
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22 | #include <Uefi.h>\r |
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23 | \r |
24 | UINT32 mCrcTable[256];\r |
25 | \r |
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26 | /**\r |
27 | Calculate CRC32 for target data.\r |
28 | \r |
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29 | @param Data The target data.\r |
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30 | @param DataSize The target data size.\r |
31 | @param CrcOut The CRC32 for target data.\r |
32 | \r |
33 | @retval EFI_SUCCESS The CRC32 for target data is calculated successfully.\r |
34 | @retval EFI_INVALID_PARAMETER Some parameter is not valid, so the CRC32 is not\r |
35 | calculated.\r |
36 | \r |
37 | **/\r |
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38 | EFI_STATUS\r |
39 | EFIAPI\r |
40 | RuntimeDriverCalculateCrc32 (\r |
41 | IN VOID *Data,\r |
42 | IN UINTN DataSize,\r |
43 | OUT UINT32 *CrcOut\r |
44 | )\r |
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45 | {\r |
46 | UINT32 Crc;\r |
47 | UINTN Index;\r |
48 | UINT8 *Ptr;\r |
49 | \r |
50 | if (Data == NULL || DataSize == 0 || CrcOut == NULL) {\r |
51 | return EFI_INVALID_PARAMETER;\r |
52 | }\r |
53 | \r |
54 | Crc = 0xffffffff;\r |
55 | for (Index = 0, Ptr = Data; Index < DataSize; Index++, Ptr++) {\r |
56 | Crc = (Crc >> 8) ^ mCrcTable[(UINT8) Crc ^ *Ptr];\r |
57 | }\r |
58 | \r |
59 | *CrcOut = Crc ^ 0xffffffff;\r |
60 | return EFI_SUCCESS;\r |
61 | }\r |
62 | \r |
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63 | \r |
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64 | /**\r |
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65 | This internal function reverses bits for 32bit data.\r |
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66 | \r |
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67 | @param Value The data to be reversed.\r |
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68 | \r |
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69 | @return Data reversed.\r |
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70 | \r |
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71 | **/\r |
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72 | UINT32\r |
73 | ReverseBits (\r |
74 | UINT32 Value\r |
75 | )\r |
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76 | {\r |
77 | UINTN Index;\r |
78 | UINT32 NewValue;\r |
79 | \r |
80 | NewValue = 0;\r |
81 | for (Index = 0; Index < 32; Index++) {\r |
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82 | if ((Value & (1 << Index)) != 0) {\r |
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83 | NewValue = NewValue | (1 << (31 - Index));\r |
84 | }\r |
85 | }\r |
86 | \r |
87 | return NewValue;\r |
88 | }\r |
89 | \r |
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90 | /**\r |
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91 | Initialize CRC32 table.\r |
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92 | \r |
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93 | **/\r |
94 | VOID\r |
95 | RuntimeDriverInitializeCrc32Table (\r |
96 | VOID\r |
97 | )\r |
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98 | {\r |
99 | UINTN TableEntry;\r |
100 | UINTN Index;\r |
101 | UINT32 Value;\r |
102 | \r |
103 | for (TableEntry = 0; TableEntry < 256; TableEntry++) {\r |
104 | Value = ReverseBits ((UINT32) TableEntry);\r |
105 | for (Index = 0; Index < 8; Index++) {\r |
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106 | if ((Value & 0x80000000) != 0) {\r |
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107 | Value = (Value << 1) ^ 0x04c11db7;\r |
108 | } else {\r |
109 | Value = Value << 1;\r |
110 | }\r |
111 | }\r |
112 | \r |
113 | mCrcTable[TableEntry] = ReverseBits (Value);\r |
114 | }\r |
115 | }\r |