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1 | #include <stdio.h> | |
2 | #include "crc32defs.h" | |
3 | #include <inttypes.h> | |
4 | ||
5 | #define ENTRIES_PER_LINE 4 | |
6 | ||
7 | #define LE_TABLE_SIZE (1 << CRC_LE_BITS) | |
8 | #define BE_TABLE_SIZE (1 << CRC_BE_BITS) | |
9 | ||
10 | static uint32_t crc32table_le[4][LE_TABLE_SIZE]; | |
11 | static uint32_t crc32table_be[4][BE_TABLE_SIZE]; | |
12 | ||
13 | /** | |
14 | * crc32init_le() - allocate and initialize LE table data | |
15 | * | |
16 | * crc is the crc of the byte i; other entries are filled in based on the | |
17 | * fact that crctable[i^j] = crctable[i] ^ crctable[j]. | |
18 | * | |
19 | */ | |
20 | static void crc32init_le(void) | |
21 | { | |
22 | unsigned i, j; | |
23 | uint32_t crc = 1; | |
24 | ||
25 | crc32table_le[0][0] = 0; | |
26 | ||
27 | for (i = 1 << (CRC_LE_BITS - 1); i; i >>= 1) { | |
28 | crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0); | |
29 | for (j = 0; j < LE_TABLE_SIZE; j += 2 * i) | |
30 | crc32table_le[0][i + j] = crc ^ crc32table_le[0][j]; | |
31 | } | |
32 | for (i = 0; i < LE_TABLE_SIZE; i++) { | |
33 | crc = crc32table_le[0][i]; | |
34 | for (j = 1; j < 4; j++) { | |
35 | crc = crc32table_le[0][crc & 0xff] ^ (crc >> 8); | |
36 | crc32table_le[j][i] = crc; | |
37 | } | |
38 | } | |
39 | } | |
40 | ||
41 | /** | |
42 | * crc32init_be() - allocate and initialize BE table data | |
43 | */ | |
44 | static void crc32init_be(void) | |
45 | { | |
46 | unsigned i, j; | |
47 | uint32_t crc = 0x80000000; | |
48 | ||
49 | crc32table_be[0][0] = 0; | |
50 | ||
51 | for (i = 1; i < BE_TABLE_SIZE; i <<= 1) { | |
52 | crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0); | |
53 | for (j = 0; j < i; j++) | |
54 | crc32table_be[0][i + j] = crc ^ crc32table_be[0][j]; | |
55 | } | |
56 | for (i = 0; i < BE_TABLE_SIZE; i++) { | |
57 | crc = crc32table_be[0][i]; | |
58 | for (j = 1; j < 4; j++) { | |
59 | crc = crc32table_be[0][(crc >> 24) & 0xff] ^ (crc << 8); | |
60 | crc32table_be[j][i] = crc; | |
61 | } | |
62 | } | |
63 | } | |
64 | ||
65 | static void output_table(uint32_t table[4][256], int len, char *trans) | |
66 | { | |
67 | int i, j; | |
68 | ||
69 | for (j = 0 ; j < 4; j++) { | |
70 | printf("{"); | |
71 | for (i = 0; i < len - 1; i++) { | |
72 | if (i % ENTRIES_PER_LINE == 0) | |
73 | printf("\n"); | |
74 | printf("%s(0x%8.8xL), ", trans, table[j][i]); | |
75 | } | |
76 | printf("%s(0x%8.8xL)},\n", trans, table[j][len - 1]); | |
77 | } | |
78 | } | |
79 | ||
80 | int main(int argc, char** argv) | |
81 | { | |
82 | printf("/* this file is generated - do not edit */\n\n"); | |
83 | ||
84 | if (CRC_LE_BITS > 1) { | |
85 | crc32init_le(); | |
86 | printf("static const u32 crc32table_le[4][256] = {"); | |
87 | output_table(crc32table_le, LE_TABLE_SIZE, "tole"); | |
88 | printf("};\n"); | |
89 | } | |
90 | ||
91 | if (CRC_BE_BITS > 1) { | |
92 | crc32init_be(); | |
93 | printf("static const u32 crc32table_be[4][256] = {"); | |
94 | output_table(crc32table_be, BE_TABLE_SIZE, "tobe"); | |
95 | printf("};\n"); | |
96 | } | |
97 | ||
98 | return 0; | |
99 | } |