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
10static uint32_t crc32table_le[4][LE_TABLE_SIZE];
11static 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 */
20static 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 */
44static 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
65static 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
80int 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}
100