summaryrefslogtreecommitdiff
path: root/MdePkg/Library/BaseLib/CheckSum.c
blob: e851164998f19b85aad940ef88706b454cb5acb7 (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
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
/** @file
  Utility functions to generate checksum based on 2's complement
  algorithm.

  Copyright (c) 2007, Intel Corporation<BR>
  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.

  Module Name:  CheckSum.c

**/

/**
  Calculate the sum of all elements in a buffer in unit of UINT8. 
  During calculation, the carry bits are dropped.

  This function calculates the sum of all elements in a buffer 
  in unit of UINT8. The carry bits in result of addition are dropped. 
  The result is returned as UINT8. If Length is Zero, then Zero is 
  returned.
  
  If Buffer is NULL, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). 

  @param  Buffer			Pointer to the buffer to carry out the sum operation.
  @param  Length	    The size, in bytes, of Buffer .

  @return Sum         The sum of Buffer with carry bits dropped during additions.

**/
UINT8
EFIAPI
CalculateSum8 (
  IN      CONST UINT8     	        *Buffer,
  IN      UINTN		  	              Length
  )
{
  UINT8     Sum;
  UINTN     Count;

  ASSERT (Buffer != NULL);
  ASSERT (Length <= (MAX_ADDRESS - ((UINTN) Buffer) + 1));

  for (Sum = 0, Count = 0; Count < Length; Count++) {
    Sum = (UINT8) (Sum + *(Buffer + Count));
  }
  
  return Sum;
}


/**
  Returns the two's complement checksum of all elements in a buffer 
  of 8-bit values.

  This function first calculates the sum of the 8-bit values in the 
  buffer specified by Buffer and Length.  The carry bits in the result 
  of addition are dropped. Then, the two's complement of the sum is 
  returned.  If Length is 0, then 0 is returned.
  
  If Buffer is NULL, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().


  @param  Buffer			Pointer to the buffer to carry out the checksum operation.
  @param  Length	    The size, in bytes, of Buffer.

  @return Checksum	  The 2's complement checksum of Buffer.

**/
UINT8
EFIAPI
CalculateCheckSum8 (
  IN      CONST UINT8     	        *Buffer,
  IN      UINTN		  	              Length
  )
{
  UINT8     CheckSum;

  CheckSum = CalculateSum8 (Buffer, Length);

  //
  // Return the checksum based on 2's complement.
  //
  return (UINT8) (0x100 - CheckSum);
}

/**
  Returns the sum of all elements in a buffer of 16-bit values.  During 
  calculation, the carry bits are dropped.

  This function calculates the sum of the 16-bit values in the buffer 
  specified by Buffer and Length. The carry bits in result of addition are dropped. 
  The 16-bit result is returned.  If Length is 0, then 0 is returned.  
  
  If Buffer is NULL, then ASSERT().
  If Buffer is not aligned on a 16-bit boundary, then ASSERT().
  If Length is not aligned on a 16-bit boundary, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

  @param  Buffer			Pointer to the buffer to carry out the sum operation.
  @param  Length	    The size, in bytes, of Buffer.

  @return Sum         The sum of Buffer with carry bits dropped during additions.

**/
UINT16
EFIAPI
CalculateSum16 (
  IN      CONST UINT16    	        *Buffer,
  IN      UINTN		  	              Length
  )
{
  UINT16    Sum;
  UINTN     Count;

  ASSERT (Buffer != NULL);
  ASSERT (((UINTN) Buffer & 0x1) == 0);
  ASSERT ((Length & 0x1) == 0);
  ASSERT (Length <= (MAX_ADDRESS - ((UINTN) Buffer) + 1));


  for (Sum = 0, Count = 0; Count < Length; Count++) {
    Sum = (UINT16) (Sum + *(Buffer + Count));
  }
  
  return Sum;
}


/**
  Returns the two's complement checksum of all elements in a buffer of 
  16-bit values.

  This function first calculates the sum of the 16-bit values in the buffer 
  specified by Buffer and Length.  The carry bits in the result of addition 
  are dropped. Then, the two's complement of the sum is returned.  If Length 
  is 0, then 0 is returned.
  
  If Buffer is NULL, then ASSERT().
  If Buffer is not aligned on a 16-bit boundary, then ASSERT().
  If Length is not aligned on a 16-bit boundary, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). 

  @param  Buffer			Pointer to the buffer to carry out the checksum operation.
  @param  Length	    The size, in bytes, of Buffer.

  @return Checksum	  The 2's complement checksum of Buffer.

**/
UINT16
EFIAPI
CalculateCheckSum16 (
  IN      CONST UINT16    	        *Buffer,
  IN      UINTN		  	              Length
  )
{
  UINT16     CheckSum;

  CheckSum = CalculateSum16 (Buffer, Length);

  //
  // Return the checksum based on 2's complement.
  //
  return (UINT16) (0x10000 - CheckSum);
}


/**
  Returns the sum of all elements in a buffer of 32-bit values.  During 
  calculation, the carry bits are dropped.

  This function calculates the sum of the 32-bit values in the buffer 
  specified by Buffer and Length. The carry bits in result of addition are dropped. 
  The 32-bit result is returned.  If Length is 0, then 0 is returned.  
  
  If Buffer is NULL, then ASSERT().
  If Buffer is not aligned on a 32-bit boundary, then ASSERT().
  If Length is not aligned on a 32-bit boundary, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

  @param  Buffer			Pointer to the buffer to carry out the sum operation.
  @param  Length	    The size, in bytes, of Buffer.

  @return Sum         The sum of Buffer with carry bits dropped during additions.

**/
UINT32
EFIAPI
CalculateSum32 (
  IN      CONST UINT32    	        *Buffer,
  IN      UINTN		  	              Length
  )
{
  UINT32    Sum;
  UINTN     Count;

  ASSERT (Buffer != NULL);
  ASSERT (((UINTN) Buffer & 0x3) == 0);
  ASSERT ((Length & 0x3) == 0);
  ASSERT (Length <= (MAX_ADDRESS - ((UINTN) Buffer) + 1));


  for (Sum = 0, Count = 0; Count < Length; Count++) {
    Sum = Sum + *(Buffer + Count);
  }
  
  return Sum;
}


/**
  Returns the two's complement checksum of all elements in a buffer of 
  32-bit values.

  This function first calculates the sum of the 32-bit values in the buffer 
  specified by Buffer and Length.  The carry bits in the result of addition 
  are dropped. Then, the two's complement of the sum is returned.  If Length 
  is 0, then 0 is returned.
  
  If Buffer is NULL, then ASSERT().
  If Buffer is not aligned on a 32-bit boundary, then ASSERT().
  If Length is not aligned on a 32-bit boundary, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). 

  @param  Buffer			Pointer to the buffer to carry out the checksum operation.
  @param  Length	    The size, in bytes, of Buffer.

  @return Checksum	  The 2's complement checksum of Buffer.

**/
UINT32
EFIAPI
CalculateCheckSum32 (
  IN      CONST UINT32    	        *Buffer,
  IN      UINTN		  	              Length
  )
{
  UINT32     CheckSum;

  CheckSum = CalculateSum32 (Buffer, Length);

  //
  // Return the checksum based on 2's complement.
  //
  return (UINT32) ((UINT32)(-1) - CheckSum + 1);
}


/**
  Returns the sum of all elements in a buffer of 64-bit values.  During 
  calculation, the carry bits are dropped.

  This function calculates the sum of the 64-bit values in the buffer 
  specified by Buffer and Length. The carry bits in result of addition are dropped. 
  The 64-bit result is returned.  If Length is 0, then 0 is returned.  
  
  If Buffer is NULL, then ASSERT().
  If Buffer is not aligned on a 64-bit boundary, then ASSERT().
  If Length is not aligned on a 64-bit boundary, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

  @param  Buffer			Pointer to the buffer to carry out the sum operation.
  @param  Length	    The size, in bytes, of Buffer.

  @return Sum         The sum of Buffer with carry bits dropped during additions.

**/
UINT64
EFIAPI
CalculateSum64 (
  IN      CONST UINT64    	        *Buffer,
  IN      UINTN		  	              Length
  )
{
  UINT64    Sum;
  UINTN     Count;

  ASSERT (Buffer != NULL);
  ASSERT (((UINTN) Buffer & 0x7) == 0);
  ASSERT ((Length & 0x7) == 0);
  ASSERT (Length <= (MAX_ADDRESS - ((UINTN) Buffer) + 1));

  for (Sum = 0, Count = 0; Count < Length; Count++) {
    Sum = Sum + *(Buffer + Count);
  }
  
  return Sum;
}


/**
  Returns the two's complement checksum of all elements in a buffer of 
  64-bit values.

  This function first calculates the sum of the 64-bit values in the buffer 
  specified by Buffer and Length.  The carry bits in the result of addition 
  are dropped. Then, the two's complement of the sum is returned.  If Length 
  is 0, then 0 is returned.
  
  If Buffer is NULL, then ASSERT().
  If Buffer is not aligned on a 64-bit boundary, then ASSERT().
  If Length is not aligned on a 64-bit boundary, then ASSERT().
  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). 

  @param  Buffer			Pointer to the buffer to carry out the checksum operation.
  @param  Length	    The size, in bytes, of Buffer.

  @return Checksum	  The 2's complement checksum of Buffer.

**/
UINT64
EFIAPI
CalculateCheckSum64 (
  IN      CONST UINT64    	        *Buffer,
  IN      UINTN		  	              Length
  )
{
  UINT64     CheckSum;

  CheckSum = CalculateSum64 (Buffer, Length);

  //
  // Return the checksum based on 2's complement.
  //
  return (UINT64) ((UINT64)(-1) - CheckSum + 1);
}