]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
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[LE_TABLE_SIZE]; | |
11 | static uint32_t crc32table_be[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; | |
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[i + j] = crc ^ crc32table_le[j]; | |
31 | } | |
32 | } | |
33 | ||
34 | /** | |
35 | * crc32init_be() - allocate and initialize BE table data | |
36 | */ | |
37 | static void crc32init_be(void) | |
38 | { | |
39 | unsigned i, j; | |
40 | uint32_t crc = 0x80000000; | |
41 | ||
42 | crc32table_be[0] = 0; | |
43 | ||
44 | for (i = 1; i < BE_TABLE_SIZE; i <<= 1) { | |
45 | crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0); | |
46 | for (j = 0; j < i; j++) | |
47 | crc32table_be[i + j] = crc ^ crc32table_be[j]; | |
48 | } | |
49 | } | |
50 | ||
51 | static void output_table(uint32_t table[], int len, char *trans) | |
52 | { | |
53 | int i; | |
54 | ||
55 | for (i = 0; i < len - 1; i++) { | |
56 | if (i % ENTRIES_PER_LINE == 0) | |
57 | printf("\n"); | |
58 | printf("%s(0x%8.8xL), ", trans, table[i]); | |
59 | } | |
60 | printf("%s(0x%8.8xL)\n", trans, table[len - 1]); | |
61 | } | |
62 | ||
63 | int main(int argc, char** argv) | |
64 | { | |
65 | printf("/* this file is generated - do not edit */\n\n"); | |
66 | ||
67 | if (CRC_LE_BITS > 1) { | |
68 | crc32init_le(); | |
69 | printf("static const u32 crc32table_le[] = {"); | |
70 | output_table(crc32table_le, LE_TABLE_SIZE, "tole"); | |
71 | printf("};\n"); | |
72 | } | |
73 | ||
74 | if (CRC_BE_BITS > 1) { | |
75 | crc32init_be(); | |
76 | printf("static const u32 crc32table_be[] = {"); | |
77 | output_table(crc32table_be, BE_TABLE_SIZE, "tobe"); | |
78 | printf("};\n"); | |
79 | } | |
80 | ||
81 | return 0; | |
82 | } |