miscutils/flash_lock_unlock.c

   1 /* vi: set sw=4 ts=4: */
   2 /* Ported to busybox from mtd-utils.
   3  *
   4  * Licensed under GPLv2, see file LICENSE in this source tree.
   5  */
   6
   7 //usage:#define flash_lock_trivial_usage
   8 //usage:       "MTD_DEVICE OFFSET SECTORS"
   9 //usage:#define flash_lock_full_usage "\n\n"
  10 //usage:       "Lock part or all of an MTD device. If SECTORS is -1, then all sectors\n"
  11 //usage:       "will be locked, regardless of the value of OFFSET"
  12 //usage:
  13 //usage:#define flash_unlock_trivial_usage
  14 //usage:       "MTD_DEVICE"
  15 //usage:#define flash_unlock_full_usage "\n\n"
  16 //usage:       "Unlock an MTD device"
  17
  18 #include "libbb.h"
  19 #include <mtd/mtd-user.h>
  20
  21 int flash_lock_unlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  22 int flash_lock_unlock_main(int argc UNUSED_PARAM, char **argv)
  23 {
  24         /* note: fields in these structs are 32-bits.
  25          * apparently we can't win anything by using off_t
  26          * or long long's for offset and/or sectors vars. */
  27         struct mtd_info_user info;
  28         struct erase_info_user lock;
  29         unsigned long offset;
  30         long sectors;
  31         int fd;
  32
  33 #define do_lock (ENABLE_FLASH_LOCK && (!ENABLE_FLASH_UNLOCK || (applet_name[6] == 'l')))
  34
  35         if (!argv[1])
  36                 bb_show_usage();
  37
  38         /* parse offset and number of sectors to lock */
  39         offset = 0;
  40         sectors = -1;
  41         if (do_lock) {
  42                 if (!argv[2] || !argv[3])
  43                         bb_show_usage();
  44                 offset = xstrtoul(argv[2], 0);
  45                 sectors = xstrtol(argv[3], 0);
  46         }
  47
  48         fd = xopen(argv[1], O_RDWR);
  49
  50         xioctl(fd, MEMGETINFO, &info);
  51
  52         lock.start = 0;
  53         lock.length = info.size;
  54         if (do_lock) {
  55                 unsigned long size = info.size - info.erasesize;
  56                 if (offset > size) {
  57                         bb_error_msg_and_die("%lx is beyond device size %lx\n",
  58                                         offset, size);
  59                 }
  60
  61                 if (sectors == -1) {
  62                         sectors = info.size / info.erasesize;
  63                 } else {
  64 // isn't this useless?
  65                         unsigned long num = info.size / info.erasesize;
  66                         if (sectors > num) {
  67                                 bb_error_msg_and_die("%ld are too many "
  68                                                 "sectors, device only has "
  69                                                 "%ld\n", sectors, num);
  70                         }
  71                 }
  72
  73                 lock.start = offset;
  74                 lock.length = sectors * info.erasesize;
  75                 xioctl(fd, MEMLOCK, &lock);
  76         } else {
  77                 xioctl(fd, MEMUNLOCK, &lock);
  78         }
  79
  80         return EXIT_SUCCESS;
  81 }