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 //config:config FLASH_LOCK
   7 //config:       bool "flash_lock (2.1 kb)"
   8 //config:       default n  # doesn't build on Ubuntu 8.04
   9 //config:       help
  10 //config:       The flash_lock binary from mtd-utils as of git head 5ec0c10d0. This
  11 //config:       utility locks part or all of the flash device.
  12 //config:
  13 //config:config FLASH_UNLOCK
  14 //config:       bool "flash_unlock (1.3 kb)"
  15 //config:       default n  # doesn't build on Ubuntu 8.04
  16 //config:       help
  17 //config:       The flash_unlock binary from mtd-utils as of git head 5ec0c10d0. This
  18 //config:       utility unlocks part or all of the flash device.
  19
  20 //                       APPLET_ODDNAME:name          main               location         suid_type     help
  21 //applet:IF_FLASH_LOCK(  APPLET_ODDNAME(flash_lock,   flash_lock_unlock, BB_DIR_USR_SBIN, BB_SUID_DROP, flash_lock))
  22 //applet:IF_FLASH_UNLOCK(APPLET_ODDNAME(flash_unlock, flash_lock_unlock, BB_DIR_USR_SBIN, BB_SUID_DROP, flash_unlock))
  23 /* not NOEXEC: if flash operation stalls, use less memory in "hung" process */
  24
  25 //kbuild:lib-$(CONFIG_FLASH_LOCK) += flash_lock_unlock.o
  26 //kbuild:lib-$(CONFIG_FLASH_UNLOCK) += flash_lock_unlock.o
  27
  28 //usage:#define flash_lock_trivial_usage
  29 //usage:       "MTD_DEVICE OFFSET SECTORS"
  30 //usage:#define flash_lock_full_usage "\n\n"
  31 //usage:       "Lock part or all of an MTD device. If SECTORS is -1, then all sectors\n"
  32 //usage:       "will be locked, regardless of the value of OFFSET"
  33 //usage:
  34 //usage:#define flash_unlock_trivial_usage
  35 //usage:       "MTD_DEVICE"
  36 //usage:#define flash_unlock_full_usage "\n\n"
  37 //usage:       "Unlock an MTD device"
  38
  39 #include "libbb.h"
  40 #include <mtd/mtd-user.h>
  41
  42 int flash_lock_unlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  43 int flash_lock_unlock_main(int argc UNUSED_PARAM, char **argv)
  44 {
  45         /* note: fields in these structs are 32-bits.
  46          * apparently we can't win anything by using off_t
  47          * or long long's for offset and/or sectors vars. */
  48         struct mtd_info_user info;
  49         struct erase_info_user lock;
  50         unsigned long offset;
  51         long sectors;
  52         int fd;
  53
  54 #define do_lock (ENABLE_FLASH_LOCK && (!ENABLE_FLASH_UNLOCK || (applet_name[6] == 'l')))
  55
  56         if (!argv[1])
  57                 bb_show_usage();
  58
  59         /* parse offset and number of sectors to lock */
  60         offset = 0;
  61         sectors = -1;
  62         if (do_lock) {
  63                 if (!argv[2] || !argv[3])
  64                         bb_show_usage();
  65                 offset = xstrtoul(argv[2], 0);
  66                 sectors = xstrtol(argv[3], 0);
  67         }
  68
  69         fd = xopen(argv[1], O_RDWR);
  70
  71         xioctl(fd, MEMGETINFO, &info);
  72
  73         lock.start = 0;
  74         lock.length = info.size;
  75         if (do_lock) {
  76                 unsigned long size = info.size - info.erasesize;
  77                 if (offset > size) {
  78                         bb_error_msg_and_die("%lx is beyond device size %lx\n",
  79                                         offset, size);
  80                 }
  81
  82                 if (sectors == -1) {
  83                         sectors = info.size / info.erasesize;
  84                 } else {
  85 // isn't this useless?
  86                         unsigned long num = info.size / info.erasesize;
  87                         if (sectors > num) {
  88                                 bb_error_msg_and_die("%ld are too many "
  89                                                 "sectors, device only has "
  90                                                 "%ld\n", sectors, num);
  91                         }
  92                 }
  93
  94                 lock.start = offset;
  95                 lock.length = sectors * info.erasesize;
  96                 xioctl(fd, MEMLOCK, &lock);
  97         } else {
  98                 xioctl(fd, MEMUNLOCK, &lock);
  99         }
 100
 101         return EXIT_SUCCESS;
 102 }