1 /* vi: set sw=4 ts=4: */
2 /*
3  * Ported to busybox from mtd-utils.
4  *
5  * Licensed under GPLv2, see file LICENSE in this source tree.
6  */
7 //config:config FLASH_LOCK
8 //config:	bool "flash_lock (2.1 kb)"
9 //config:	default n  # doesn't build on Ubuntu 8.04
10 //config:	help
11 //config:	The flash_lock binary from mtd-utils as of git head 5ec0c10d0. This
12 //config:	utility locks part or all of the flash device.
13 //config:
14 //config:config FLASH_UNLOCK
15 //config:	bool "flash_unlock (1.3 kb)"
16 //config:	default n  # doesn't build on Ubuntu 8.04
17 //config:	help
18 //config:	The flash_unlock binary from mtd-utils as of git head 5ec0c10d0. This
19 //config:	utility unlocks part or all of the flash device.
20 
21 //                       APPLET_ODDNAME:name          main               location         suid_type     help
22 //applet:IF_FLASH_LOCK(  APPLET_ODDNAME(flash_lock,   flash_lock_unlock, BB_DIR_USR_SBIN, BB_SUID_DROP, flash_lock))
23 //applet:IF_FLASH_UNLOCK(APPLET_ODDNAME(flash_unlock, flash_lock_unlock, BB_DIR_USR_SBIN, BB_SUID_DROP, flash_unlock))
24 /* not NOEXEC: if flash operation stalls, use less memory in "hung" process */
25 
26 //kbuild:lib-$(CONFIG_FLASH_LOCK) += flash_lock_unlock.o
27 //kbuild:lib-$(CONFIG_FLASH_UNLOCK) += flash_lock_unlock.o
28 
29 //usage:#define flash_lock_trivial_usage
30 //usage:       "MTD_DEVICE OFFSET SECTORS"
31 //usage:#define flash_lock_full_usage "\n\n"
32 //usage:       "Lock part or all of an MTD device. If SECTORS is -1, then all sectors\n"
33 //usage:       "will be locked, regardless of the value of OFFSET"
34 //usage:
35 //usage:#define flash_unlock_trivial_usage
36 //usage:       "MTD_DEVICE"
37 //usage:#define flash_unlock_full_usage "\n\n"
38 //usage:       "Unlock an MTD device"
39 
40 #include "libbb.h"
41 #include <mtd/mtd-user.h>
42 
43 int flash_lock_unlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
flash_lock_unlock_main(int argc UNUSED_PARAM,char ** argv)44 int flash_lock_unlock_main(int argc UNUSED_PARAM, char **argv)
45 {
46 	/* note: fields in these structs are 32-bits.
47 	 * apparently we can't win anything by using off_t
48 	 * or long long's for offset and/or sectors vars. */
49 	struct mtd_info_user info;
50 	struct erase_info_user lock;
51 	unsigned long offset;
52 	long sectors;
53 	int fd;
54 
55 #define do_lock (ENABLE_FLASH_LOCK && (!ENABLE_FLASH_UNLOCK || (applet_name[6] == 'l')))
56 
57 	if (!argv[1])
58 		bb_show_usage();
59 
60 	/* parse offset and number of sectors to lock */
61 	offset = 0;
62 	sectors = -1;
63 	if (do_lock) {
64 		if (!argv[2] || !argv[3])
65 			bb_show_usage();
66 		offset = xstrtoul(argv[2], 0);
67 		sectors = xstrtol(argv[3], 0);
68 	}
69 
70 	fd = xopen(argv[1], O_RDWR);
71 
72 	xioctl(fd, MEMGETINFO, &info);
73 
74 	lock.start = 0;
75 	lock.length = info.size;
76 	if (do_lock) {
77 		unsigned long size = info.size - info.erasesize;
78 		if (offset > size) {
79 			bb_error_msg_and_die("%lx is beyond device size %lx\n",
80 					offset, size);
81 		}
82 
83 		if (sectors == -1) {
84 			sectors = info.size / info.erasesize;
85 		} else {
86 // isn't this useless?
87 			unsigned long num = info.size / info.erasesize;
88 			if (sectors > num) {
89 				bb_error_msg_and_die("%ld are too many "
90 						"sectors, device only has "
91 						"%ld\n", sectors, num);
92 			}
93 		}
94 
95 		lock.start = offset;
96 		lock.length = sectors * info.erasesize;
97 		xioctl(fd, MEMLOCK, &lock);
98 	} else {
99 		xioctl(fd, MEMUNLOCK, &lock);
100 	}
101 
102 	return EXIT_SUCCESS;
103 }
104