tools/firmware-utils/src/nand_ecc.c

   1 /*
   2  * calculate ecc code for nand flash
   3  *
   4  * Copyright (C) 2008 yajin <yajin@vm-kernel.org>
   5  * Copyright (C) 2009 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 or
  10  * (at your option) version 3 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20  * MA 02111-1307 USA
  21  */
  22
  23
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <unistd.h>
  27 #include <stdlib.h>
  28 #include <stdint.h>
  29 #include <fcntl.h>
  30 #include <stdio.h>
  31
  32 #define DEF_NAND_PAGE_SIZE   2048
  33 #define DEF_NAND_OOB_SIZE     64
  34 #define DEF_NAND_ECC_OFFSET   0x28
  35
  36 static int page_size = DEF_NAND_PAGE_SIZE;
  37 static int oob_size = DEF_NAND_OOB_SIZE;
  38 static int ecc_offset = DEF_NAND_ECC_OFFSET;
  39
  40 /*
  41  * Pre-calculated 256-way 1 byte column parity
  42  */
  43 static const uint8_t nand_ecc_precalc_table[] = {
  44         0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a, 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00,
  45         0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f, 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
  46         0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c, 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
  47         0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59, 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
  48         0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33, 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
  49         0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56, 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
  50         0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55, 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
  51         0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30, 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
  52         0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30, 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
  53         0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55, 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
  54         0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56, 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
  55         0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33, 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
  56         0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59, 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
  57         0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c, 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
  58         0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f, 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
  59         0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a, 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00
  60 };
  61
  62 /**
  63  * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256-byte block
  64  * @dat:        raw data
  65  * @ecc_code:   buffer for ECC
  66  */
  67 int nand_calculate_ecc(const uint8_t *dat,
  68                        uint8_t *ecc_code)
  69 {
  70         uint8_t idx, reg1, reg2, reg3, tmp1, tmp2;
  71         int i;
  72
  73         /* Initialize variables */
  74         reg1 = reg2 = reg3 = 0;
  75
  76         /* Build up column parity */
  77         for(i = 0; i < 256; i++) {
  78                 /* Get CP0 - CP5 from table */
  79                 idx = nand_ecc_precalc_table[*dat++];
  80                 reg1 ^= (idx & 0x3f);
  81
  82                 /* All bit XOR = 1 ? */
  83                 if (idx & 0x40) {
  84                         reg3 ^= (uint8_t) i;
  85                         reg2 ^= ~((uint8_t) i);
  86                 }
  87         }
  88
  89         /* Create non-inverted ECC code from line parity */
  90         tmp1  = (reg3 & 0x80) >> 0; /* B7 -> B7 */
  91         tmp1 |= (reg2 & 0x80) >> 1; /* B7 -> B6 */
  92         tmp1 |= (reg3 & 0x40) >> 1; /* B6 -> B5 */
  93         tmp1 |= (reg2 & 0x40) >> 2; /* B6 -> B4 */
  94         tmp1 |= (reg3 & 0x20) >> 2; /* B5 -> B3 */
  95         tmp1 |= (reg2 & 0x20) >> 3; /* B5 -> B2 */
  96         tmp1 |= (reg3 & 0x10) >> 3; /* B4 -> B1 */
  97         tmp1 |= (reg2 & 0x10) >> 4; /* B4 -> B0 */
  98
  99         tmp2  = (reg3 & 0x08) << 4; /* B3 -> B7 */
 100         tmp2 |= (reg2 & 0x08) << 3; /* B3 -> B6 */
 101         tmp2 |= (reg3 & 0x04) << 3; /* B2 -> B5 */
 102         tmp2 |= (reg2 & 0x04) << 2; /* B2 -> B4 */
 103         tmp2 |= (reg3 & 0x02) << 2; /* B1 -> B3 */
 104         tmp2 |= (reg2 & 0x02) << 1; /* B1 -> B2 */
 105         tmp2 |= (reg3 & 0x01) << 1; /* B0 -> B1 */
 106         tmp2 |= (reg2 & 0x01) << 0; /* B7 -> B0 */
 107
 108         /* Calculate final ECC code */
 109 #ifdef CONFIG_MTD_NAND_ECC_SMC
 110         ecc_code[0] = ~tmp2;
 111         ecc_code[1] = ~tmp1;
 112 #else
 113         ecc_code[0] = ~tmp1;
 114         ecc_code[1] = ~tmp2;
 115 #endif
 116         ecc_code[2] = ((~reg1) << 2) | 0x03;
 117
 118         return 0;
 119 }
 120
 121 /*
 122  *  usage: bb-nandflash-ecc    start_address  size
 123  */
 124 void usage(const char *prog)
 125 {
 126         fprintf(stderr, "Usage: %s [options] <input> <output>\n"
 127                 "Options:\n"
 128                 "    -p <pagesize>      NAND page size (default: %d)\n"
 129                 "    -o <oobsize>       NAND OOB size (default: %d)\n"
 130                 "    -e <offset>        NAND ECC offset (default: %d)\n"
 131                 "\n", prog, DEF_NAND_PAGE_SIZE, DEF_NAND_OOB_SIZE,
 132                 DEF_NAND_ECC_OFFSET);
 133         exit(1);
 134 }
 135
 136 /*start_address/size does not include oob
 137   */
 138 int main(int argc, char **argv)
 139 {
 140         uint8_t *page_data = NULL;
 141         uint8_t *ecc_data;
 142         int infd = -1, outfd = -1;
 143         int ret = 1;
 144         ssize_t bytes;
 145         int ch;
 146
 147         while ((ch = getopt(argc, argv, "e:o:p:")) != -1) {
 148                 switch(ch) {
 149                 case 'p':
 150                         page_size = strtoul(optarg, NULL, 0);
 151                         break;
 152                 case 'o':
 153                         oob_size = strtoul(optarg, NULL, 0);
 154                         break;
 155                 case 'e':
 156                         ecc_offset = strtoul(optarg, NULL, 0);
 157                         break;
 158                 default:
 159                         usage(argv[0]);
 160                 }
 161         }
 162         argc -= optind;
 163         if (argc < 2)
 164                 usage(argv[0]);
 165
 166         argv += optind;
 167
 168         infd = open(argv[0], O_RDONLY, 0);
 169         if (infd < 0) {
 170                 perror("open input file");
 171                 goto out;
 172         }
 173
 174         outfd = open(argv[1], O_WRONLY|O_CREAT|O_TRUNC, 0644);
 175         if (outfd < 0) {
 176                 perror("open output file");
 177                 goto out;
 178         }
 179
 180         page_data = malloc(page_size + oob_size);
 181
 182         while ((bytes = read(infd, page_data, page_size)) == page_size) {
 183                 int j;
 184
 185                 ecc_data = page_data + page_size + ecc_offset;
 186                 for (j = 0; j < page_size / 256; j++)
 187                 {
 188                         nand_calculate_ecc(page_data + j * 256, ecc_data);
 189                         ecc_data += 3;
 190                 }
 191                 write(outfd, page_data, page_size + oob_size);
 192         }
 193
 194         ret = 0;
 195 out:
 196         if (infd >= 0)
 197                 close(infd);
 198         if (outfd >= 0)
 199                 close(outfd);
 200         if (page_data)
 201                 free(page_data);
 202         return ret;
 203 }
 204