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Sources/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 
191 

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