src/udev/mtd_probe/probe_smartmedia.c

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