src/udev/mtd_probe/probe_smartmedia.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright © 2010 - Maxim Levitsky
   4  *
   5  * mtd_probe is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * mtd_probe is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with mtd_probe; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor,
  18  * Boston, MA  02110-1301  USA
  19  */
  20
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <mtd/mtd-user.h>
  24 #include <stdint.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/stat.h>
  29 #include <sys/types.h>
  30 #include <unistd.h>
  31
  32 #include "alloc-util.h"
  33 #include "mtd_probe.h"
  34
  35 static const uint8_t cis_signature[] = {
  36         0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
  37 };
  38
  39 int probe_smart_media(int mtd_fd, mtd_info_t* info) {
  40         int sector_size;
  41         int block_size;
  42         int size_in_megs;
  43         int spare_count;
  44         _cleanup_free_ uint8_t *cis_buffer = NULL;
  45         int offset;
  46         int cis_found = 0;
  47
  48         cis_buffer = malloc(SM_SECTOR_SIZE);
  49         if (!cis_buffer)
  50                 return log_oom();
  51
  52         if (info->type != MTD_NANDFLASH) {
  53                 log_debug("Not marked MTD_NANDFLASH.");
  54                 return -EINVAL;
  55         }
  56
  57         sector_size = info->writesize;
  58         block_size = info->erasesize;
  59         size_in_megs = info->size / (1024 * 1024);
  60
  61         if (!IN_SET(sector_size, SM_SECTOR_SIZE, SM_SMALL_PAGE)) {
  62                 log_debug("Unexpected sector size: %i", sector_size);
  63                 return -EINVAL;
  64         }
  65
  66         switch(size_in_megs) {
  67         case 1:
  68         case 2:
  69                 spare_count = 6;
  70                 break;
  71         case 4:
  72                 spare_count = 12;
  73                 break;
  74         default:
  75                 spare_count = 24;
  76                 break;
  77         }
  78
  79         for (offset = 0; offset < block_size * spare_count; offset += sector_size) {
  80                 (void) lseek(mtd_fd, SEEK_SET, offset);
  81
  82                 if (read(mtd_fd, cis_buffer, SM_SECTOR_SIZE) == SM_SECTOR_SIZE) {
  83                         cis_found = 1;
  84                         break;
  85                 }
  86         }
  87
  88         if (!cis_found) {
  89                 log_debug("CIS not found");
  90                 return -EINVAL;
  91         }
  92
  93         if (memcmp(cis_buffer, cis_signature, sizeof(cis_signature)) != 0 &&
  94             memcmp(cis_buffer + SM_SMALL_PAGE, cis_signature, sizeof(cis_signature)) != 0) {
  95                 log_debug("CIS signature didn't match");
  96                 return -EINVAL;
  97         }
  98
  99         printf("MTD_FTL=smartmedia\n");
 100         return 0;
 101 }