1 /* vi: set sw=4 ts=4: */
3 * freeramdisk and fdflush implementations for busybox
5 * Copyright (C) 2000 and written by Emanuele Caratti <wiz@iol.it>
6 * Adjusted a bit by Erik Andersen <andersen@codepoet.org>
7 * Unified with fdflush by Tito Ragusa <farmatito@tiscali.it>
9 * Licensed under GPLv2, see file LICENSE in this source tree.
11 //config:config FDFLUSH
12 //config: bool "fdflush"
14 //config: select PLATFORM_LINUX
16 //config: fdflush is only needed when changing media on slightly-broken
17 //config: removable media drives. It is used to make Linux believe that a
18 //config: hardware disk-change switch has been actuated, which causes Linux to
19 //config: forget anything it has cached from the previous media. If you have
20 //config: such a slightly-broken drive, you will need to run fdflush every time
21 //config: you change a disk. Most people have working hardware and can safely
22 //config: leave this disabled.
24 //config:config FREERAMDISK
25 //config: bool "freeramdisk"
27 //config: select PLATFORM_LINUX
29 //config: Linux allows you to create ramdisks. This utility allows you to
30 //config: delete them and completely free all memory that was used for the
31 //config: ramdisk. For example, if you boot Linux into a ramdisk and later
32 //config: pivot_root, you may want to free the memory that is allocated to the
33 //config: ramdisk. If you have no use for freeing memory from a ramdisk, leave
34 //config: this disabled.
36 //applet:IF_FDFLUSH(APPLET_ODDNAME(fdflush, freeramdisk, BB_DIR_BIN, BB_SUID_DROP, fdflush))
37 //applet:IF_FREERAMDISK(APPLET(freeramdisk, BB_DIR_SBIN, BB_SUID_DROP))
39 //kbuild:lib-$(CONFIG_FDFLUSH) += freeramdisk.o
40 //kbuild:lib-$(CONFIG_FREERAMDISK) += freeramdisk.o
42 //usage:#define freeramdisk_trivial_usage
44 //usage:#define freeramdisk_full_usage "\n\n"
45 //usage: "Free all memory used by the specified ramdisk"
47 //usage:#define freeramdisk_example_usage
48 //usage: "$ freeramdisk /dev/ram2\n"
50 //usage:#define fdflush_trivial_usage
52 //usage:#define fdflush_full_usage "\n\n"
53 //usage: "Force floppy disk drive to detect disk change"
55 #include <sys/mount.h>
58 /* From <linux/fd.h> */
59 #define FDFLUSH _IO(2,0x4b)
61 int freeramdisk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
62 int freeramdisk_main(int argc UNUSED_PARAM, char **argv)
66 fd = xopen(single_argv(argv), O_RDWR);
68 // Act like freeramdisk, fdflush, or both depending on configuration.
69 ioctl_or_perror_and_die(fd, (ENABLE_FREERAMDISK && applet_name[1] == 'r')
70 || !ENABLE_FDFLUSH ? BLKFLSBUF : FDFLUSH, NULL, "%s", argv[1]);
72 if (ENABLE_FEATURE_CLEAN_UP) close(fd);