OpenCores
URL https://opencores.org/ocsvn/or1k_soc_on_altera_embedded_dev_kit/or1k_soc_on_altera_embedded_dev_kit/trunk

Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

[/] [or1k_soc_on_altera_embedded_dev_kit/] [tags/] [linux-2.6/] [linux-2.6.24_or32_unified_v2.3/] [lib/] [gen_crc32table.c] - Blame information for rev 8

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 3 xianfeng
#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
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.