tools/firmware-utils/src/nand_ecc.c

   1 // SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only
   2 /*
   3  * calculate ecc code for nand flash
   4  *
   5  * Copyright (C) 2008 yajin <yajin@vm-kernel.org>
   6  * Copyright (C) 2009 Felix Fietkau <nbd@nbd.name>
   7  */
   8
   9
  10 #include <sys/types.h>
  11 #include <sys/stat.h>
  12 #include <unistd.h>
  13 #include <stdlib.h>
  14 #include <stdint.h>
  15 #include <fcntl.h>
  16 #include <stdio.h>
  17
  18 #define DEF_NAND_PAGE_SIZE   2048
  19 #define DEF_NAND_OOB_SIZE     64
  20 #define DEF_NAND_ECC_OFFSET   0x28
  21
  22 static int page_size = DEF_NAND_PAGE_SIZE;
  23 static int oob_size = DEF_NAND_OOB_SIZE;
  24 static int ecc_offset = DEF_NAND_ECC_OFFSET;
  25
  26 /*
  27  * Pre-calculated 256-way 1 byte column parity
  28  */
  29 static const uint8_t nand_ecc_precalc_table[] = {
  30         0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a, 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00,
  31         0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f, 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
  32         0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c, 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
  33         0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59, 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
  34         0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33, 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
  35         0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56, 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
  36         0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55, 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
  37         0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30, 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
  38         0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30, 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
  39         0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55, 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
  40         0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56, 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
  41         0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33, 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
  42         0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59, 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
  43         0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c, 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
  44         0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f, 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
  45         0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a, 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00
  46 };
  47
  48 /**
  49  * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256-byte block
  50  * @dat:        raw data
  51  * @ecc_code:   buffer for ECC
  52  */
  53 int nand_calculate_ecc(const uint8_t *dat,
  54                        uint8_t *ecc_code)
  55 {
  56         uint8_t idx, reg1, reg2, reg3, tmp1, tmp2;
  57         int i;
  58
  59         /* Initialize variables */
  60         reg1 = reg2 = reg3 = 0;
  61
  62         /* Build up column parity */
  63         for(i = 0; i < 256; i++) {
  64                 /* Get CP0 - CP5 from table */
  65                 idx = nand_ecc_precalc_table[*dat++];
  66                 reg1 ^= (idx & 0x3f);
  67
  68                 /* All bit XOR = 1 ? */
  69                 if (idx & 0x40) {
  70                         reg3 ^= (uint8_t) i;
  71                         reg2 ^= ~((uint8_t) i);
  72                 }
  73         }
  74
  75         /* Create non-inverted ECC code from line parity */
  76         tmp1  = (reg3 & 0x80) >> 0; /* B7 -> B7 */
  77         tmp1 |= (reg2 & 0x80) >> 1; /* B7 -> B6 */
  78         tmp1 |= (reg3 & 0x40) >> 1; /* B6 -> B5 */
  79         tmp1 |= (reg2 & 0x40) >> 2; /* B6 -> B4 */
  80         tmp1 |= (reg3 & 0x20) >> 2; /* B5 -> B3 */
  81         tmp1 |= (reg2 & 0x20) >> 3; /* B5 -> B2 */
  82         tmp1 |= (reg3 & 0x10) >> 3; /* B4 -> B1 */
  83         tmp1 |= (reg2 & 0x10) >> 4; /* B4 -> B0 */
  84
  85         tmp2  = (reg3 & 0x08) << 4; /* B3 -> B7 */
  86         tmp2 |= (reg2 & 0x08) << 3; /* B3 -> B6 */
  87         tmp2 |= (reg3 & 0x04) << 3; /* B2 -> B5 */
  88         tmp2 |= (reg2 & 0x04) << 2; /* B2 -> B4 */
  89         tmp2 |= (reg3 & 0x02) << 2; /* B1 -> B3 */
  90         tmp2 |= (reg2 & 0x02) << 1; /* B1 -> B2 */
  91         tmp2 |= (reg3 & 0x01) << 1; /* B0 -> B1 */
  92         tmp2 |= (reg2 & 0x01) << 0; /* B7 -> B0 */
  93
  94         /* Calculate final ECC code */
  95 #ifdef CONFIG_MTD_NAND_ECC_SMC
  96         ecc_code[0] = ~tmp2;
  97         ecc_code[1] = ~tmp1;
  98 #else
  99         ecc_code[0] = ~tmp1;
 100         ecc_code[1] = ~tmp2;
 101 #endif
 102         ecc_code[2] = ((~reg1) << 2) | 0x03;
 103
 104         return 0;
 105 }
 106
 107 /*
 108  *  usage: bb-nandflash-ecc    start_address  size
 109  */
 110 void usage(const char *prog)
 111 {
 112         fprintf(stderr, "Usage: %s [options] <input> <output>\n"
 113                 "Options:\n"
 114                 "    -p <pagesize>      NAND page size (default: %d)\n"
 115                 "    -o <oobsize>       NAND OOB size (default: %d)\n"
 116                 "    -e <offset>        NAND ECC offset (default: %d)\n"
 117                 "\n", prog, DEF_NAND_PAGE_SIZE, DEF_NAND_OOB_SIZE,
 118                 DEF_NAND_ECC_OFFSET);
 119         exit(1);
 120 }
 121
 122 /*start_address/size does not include oob
 123   */
 124 int main(int argc, char **argv)
 125 {
 126         uint8_t *page_data = NULL;
 127         uint8_t *ecc_data;
 128         int infd = -1, outfd = -1;
 129         int ret = 1;
 130         ssize_t bytes;
 131         int ch;
 132
 133         while ((ch = getopt(argc, argv, "e:o:p:")) != -1) {
 134                 switch(ch) {
 135                 case 'p':
 136                         page_size = strtoul(optarg, NULL, 0);
 137                         break;
 138                 case 'o':
 139                         oob_size = strtoul(optarg, NULL, 0);
 140                         break;
 141                 case 'e':
 142                         ecc_offset = strtoul(optarg, NULL, 0);
 143                         break;
 144                 default:
 145                         usage(argv[0]);
 146                 }
 147         }
 148         argc -= optind;
 149         if (argc < 2)
 150                 usage(argv[0]);
 151
 152         argv += optind;
 153
 154         infd = open(argv[0], O_RDONLY, 0);
 155         if (infd < 0) {
 156                 perror("open input file");
 157                 goto out;
 158         }
 159
 160         outfd = open(argv[1], O_WRONLY|O_CREAT|O_TRUNC, 0644);
 161         if (outfd < 0) {
 162                 perror("open output file");
 163                 goto out;
 164         }
 165
 166         page_data = malloc(page_size + oob_size);
 167
 168         while ((bytes = read(infd, page_data, page_size)) == page_size) {
 169                 int j;
 170
 171                 ecc_data = page_data + page_size + ecc_offset;
 172                 for (j = 0; j < page_size / 256; j++)
 173                 {
 174                         nand_calculate_ecc(page_data + j * 256, ecc_data);
 175                         ecc_data += 3;
 176                 }
 177                 write(outfd, page_data, page_size + oob_size);
 178         }
 179
 180         ret = 0;
 181 out:
 182         if (infd >= 0)
 183                 close(infd);
 184         if (outfd >= 0)
 185                 close(outfd);
 186         if (page_data)
 187                 free(page_data);
 188         return ret;
 189 }
 190