# DO NOT EDIT. This file is generated from Config.src # # For a description of the syntax of this configuration file, # see docs/Kconfig-language.txt. # menu "Linux System Utilities" config ACPID bool "acpid (9 kb)" default y select PLATFORM_LINUX help acpid listens to ACPI events coming either in textual form from /proc/acpi/event (though it is marked deprecated it is still widely used and _is_ a standard) or in binary form from specified evdevs (just use /dev/input/event*). It parses the event to retrieve ACTION and a possible PARAMETER. It then spawns /etc/acpi/[/] either via run-parts (if the resulting path is a directory) or directly as an executable. N.B. acpid relies on run-parts so have the latter installed. config FEATURE_ACPID_COMPAT bool "Accept and ignore redundant options" default y depends on ACPID help Accept and ignore compatibility options -g -m -s -S -v. config BLKDISCARD bool "blkdiscard (4.3 kb)" default y select PLATFORM_LINUX help blkdiscard discards sectors on a given device. config BLKID bool "blkid (12 kb)" default y select PLATFORM_LINUX select VOLUMEID help Lists labels and UUIDs of all filesystems. config FEATURE_BLKID_TYPE bool "Print filesystem type" default y depends on BLKID help Show TYPE="filesystem type" config BLOCKDEV bool "blockdev (2.3 kb)" default y help Performs some ioctls with block devices. config CAL bool "cal (5.8 kb)" default y help cal is used to display a monthly calendar. config CHRT bool "chrt (4.7 kb)" default y help Manipulate real-time attributes of a process. This requires sched_{g,s}etparam support in your libc. config DMESG bool "dmesg (3.7 kb)" default y select PLATFORM_LINUX help dmesg is used to examine or control the kernel ring buffer. When the Linux kernel prints messages to the system log, they are stored in the kernel ring buffer. You can use dmesg to print the kernel's ring buffer, clear the kernel ring buffer, change the size of the kernel ring buffer, and change the priority level at which kernel messages are also logged to the system console. Enable this option if you wish to enable the 'dmesg' utility. config FEATURE_DMESG_PRETTY bool "Pretty output" default y depends on DMESG help If you wish to scrub the syslog level from the output, say 'Y' here. The syslog level is a string prefixed to every line with the form "<#>". With this option you will see: # dmesg Linux version 2.6.17.4 ..... BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 000000000009f000 (usable) Without this option you will see: # dmesg <5>Linux version 2.6.17.4 ..... <6>BIOS-provided physical RAM map: <6> BIOS-e820: 0000000000000000 - 000000000009f000 (usable) config EJECT bool "eject (4 kb)" default y select PLATFORM_LINUX help Used to eject cdroms. (defaults to /dev/cdrom) config FEATURE_EJECT_SCSI bool "SCSI support" default y depends on EJECT help Add the -s option to eject, this allows to eject SCSI-Devices and usb-storage devices. config FALLOCATE bool "fallocate (4.1 kb)" default y help Preallocate space for files. config FATATTR bool "fatattr (1.9 kb)" default y select PLATFORM_LINUX help fatattr lists or changes the file attributes on a fat file system. config FBSET bool "fbset (5.9 kb)" default y select PLATFORM_LINUX help fbset is used to show or change the settings of a Linux frame buffer device. The frame buffer device provides a simple and unique interface to access a graphics display. Enable this option if you wish to enable the 'fbset' utility. config FEATURE_FBSET_FANCY bool "Enable extra options" default y depends on FBSET help This option enables extended fbset options, allowing one to set the framebuffer size, color depth, etc. interface to access a graphics display. Enable this option if you wish to enable extended fbset options. config FEATURE_FBSET_READMODE bool "Enable readmode support" default y depends on FBSET help This option allows fbset to read the video mode database stored by default as /etc/fb.modes, which can be used to set frame buffer device to pre-defined video modes. config FDFORMAT bool "fdformat (4.4 kb)" default y select PLATFORM_LINUX help fdformat is used to low-level format a floppy disk. config FDISK bool "fdisk (37 kb)" default y select PLATFORM_LINUX help The fdisk utility is used to divide hard disks into one or more logical disks, which are generally called partitions. This utility can be used to list and edit the set of partitions or BSD style 'disk slices' that are defined on a hard drive. config FDISK_SUPPORT_LARGE_DISKS bool "Support over 4GB disks" default y depends on FDISK depends on !LFS # with LFS no special code is needed config FEATURE_FDISK_WRITABLE bool "Write support" default y depends on FDISK help Enabling this option allows you to create or change a partition table and write those changes out to disk. If you leave this option disabled, you will only be able to view the partition table. config FEATURE_AIX_LABEL bool "Support AIX disklabels" default n depends on FDISK && FEATURE_FDISK_WRITABLE help Enabling this option allows you to create or change AIX disklabels. Most people can safely leave this option disabled. config FEATURE_SGI_LABEL bool "Support SGI disklabels" default n depends on FDISK && FEATURE_FDISK_WRITABLE help Enabling this option allows you to create or change SGI disklabels. Most people can safely leave this option disabled. config FEATURE_SUN_LABEL bool "Support SUN disklabels" default n depends on FDISK && FEATURE_FDISK_WRITABLE help Enabling this option allows you to create or change SUN disklabels. Most people can safely leave this option disabled. config FEATURE_OSF_LABEL bool "Support BSD disklabels" default n depends on FDISK && FEATURE_FDISK_WRITABLE help Enabling this option allows you to create or change BSD disklabels and define and edit BSD disk slices. config FEATURE_GPT_LABEL bool "Support GPT disklabels" default n depends on FDISK && FEATURE_FDISK_WRITABLE help Enabling this option allows you to view GUID Partition Table disklabels. config FEATURE_FDISK_ADVANCED bool "Support expert mode" default y depends on FDISK && FEATURE_FDISK_WRITABLE help Enabling this option allows you to do terribly unsafe things like define arbitrary drive geometry, move the beginning of data in a partition, and similarly evil things. Unless you have a very good reason you would be wise to leave this disabled. config FINDFS bool "findfs (12 kb)" default y select PLATFORM_LINUX select VOLUMEID help Prints the name of a filesystem with given label or UUID. config FLOCK bool "flock (6.3 kb)" default y help Manage locks from shell scripts config FDFLUSH bool "fdflush (1.3 kb)" default y select PLATFORM_LINUX help fdflush is only needed when changing media on slightly-broken removable media drives. It is used to make Linux believe that a hardware disk-change switch has been actuated, which causes Linux to forget anything it has cached from the previous media. If you have such a slightly-broken drive, you will need to run fdflush every time you change a disk. Most people have working hardware and can safely leave this disabled. config FREERAMDISK bool "freeramdisk (1.3 kb)" default y select PLATFORM_LINUX help Linux allows you to create ramdisks. This utility allows you to delete them and completely free all memory that was used for the ramdisk. For example, if you boot Linux into a ramdisk and later pivot_root, you may want to free the memory that is allocated to the ramdisk. If you have no use for freeing memory from a ramdisk, leave this disabled. config FSCK_MINIX bool "fsck.minix (13 kb)" default y help The minix filesystem is a nice, small, compact, read-write filesystem with little overhead. It is not a journaling filesystem however and can experience corruption if it is not properly unmounted or if the power goes off in the middle of a write. This utility allows you to check for and attempt to repair any corruption that occurs to a minix filesystem. config FSFREEZE bool "fsfreeze (3.5 kb)" default y select PLATFORM_LINUX select LONG_OPTS help Halt new accesses and flush writes on a mounted filesystem. config FSTRIM bool "fstrim (4.4 kb)" default y select PLATFORM_LINUX help Discard unused blocks on a mounted filesystem. config GETOPT bool "getopt (5.8 kb)" default y help The getopt utility is used to break up (parse) options in command lines to make it easy to write complex shell scripts that also check for legal (and illegal) options. If you want to write horribly complex shell scripts, or use some horribly complex shell script written by others, this utility may be for you. Most people will wisely leave this disabled. config FEATURE_GETOPT_LONG bool "Support -l LONGOPTs" default y depends on GETOPT && LONG_OPTS help Enable support for long options (option -l). config HEXDUMP bool "hexdump (8.6 kb)" default y help The hexdump utility is used to display binary data in a readable way that is comparable to the output from most hex editors. config FEATURE_HEXDUMP_REVERSE bool "Support -R, reverse of 'hexdump -Cv'" default y depends on HEXDUMP help The hexdump utility is used to display binary data in an ascii readable way. This option creates binary data from an ascii input. NB: this option is non-standard. It's unwise to use it in scripts aimed to be portable. config HD bool "hd (7.8 kb)" default y help hd is an alias to hexdump -C. config XXD bool "xxd (8.9 kb)" default y help The xxd utility is used to display binary data in a readable way that is comparable to the output from most hex editors. config HWCLOCK bool "hwclock (5.8 kb)" default y select PLATFORM_LINUX help The hwclock utility is used to read and set the hardware clock on a system. This is primarily used to set the current time on shutdown in the hardware clock, so the hardware will keep the correct time when Linux is _not_ running. config FEATURE_HWCLOCK_ADJTIME_FHS bool "Use FHS /var/lib/hwclock/adjtime" default n # util-linux-ng in Fedora 13 still uses /etc/adjtime depends on HWCLOCK help Starting with FHS 2.3, the adjtime state file is supposed to exist at /var/lib/hwclock/adjtime instead of /etc/adjtime. If you wish to use the FHS behavior, answer Y here, otherwise answer N for the classic /etc/adjtime path. pathname.com/fhs/pub/fhs-2.3.html#VARLIBHWCLOCKSTATEDIRECTORYFORHWCLO config IONICE bool "ionice (3.8 kb)" default y select PLATFORM_LINUX help Set/set program io scheduling class and priority Requires kernel >= 2.6.13 config IPCRM bool "ipcrm (3.2 kb)" default y help The ipcrm utility allows the removal of System V interprocess communication (IPC) objects and the associated data structures from the system. config IPCS bool "ipcs (11 kb)" default y select PLATFORM_LINUX help The ipcs utility is used to provide information on the currently allocated System V interprocess (IPC) objects in the system. config LAST bool "last (6.1 kb)" default y depends on FEATURE_WTMP help 'last' displays a list of the last users that logged into the system. config FEATURE_LAST_FANCY bool "Output extra information" default y depends on LAST help 'last' displays detailed information about the last users that logged into the system (mimics sysvinit last). +900 bytes. config LOSETUP bool "losetup (5.5 kb)" default y select PLATFORM_LINUX help losetup is used to associate or detach a loop device with a regular file or block device, and to query the status of a loop device. This version does not currently support enabling data encryption. config LSPCI bool "lspci (6.3 kb)" default y #select PLATFORM_LINUX help lspci is a utility for displaying information about PCI buses in the system and devices connected to them. This version uses sysfs (/sys/bus/pci/devices) only. config LSUSB bool "lsusb (4.2 kb)" default y #select PLATFORM_LINUX help lsusb is a utility for displaying information about USB buses in the system and devices connected to them. This version uses sysfs (/sys/bus/usb/devices) only. config MDEV bool "mdev (17 kb)" default y select PLATFORM_LINUX help mdev is a mini-udev implementation for dynamically creating device nodes in the /dev directory. For more information, please see docs/mdev.txt config FEATURE_MDEV_CONF bool "Support /etc/mdev.conf" default y depends on MDEV help Add support for the mdev config file to control ownership and permissions of the device nodes. For more information, please see docs/mdev.txt config FEATURE_MDEV_RENAME bool "Support subdirs/symlinks" default y depends on FEATURE_MDEV_CONF help Add support for renaming devices and creating symlinks. For more information, please see docs/mdev.txt config FEATURE_MDEV_RENAME_REGEXP bool "Support regular expressions substitutions when renaming device" default y depends on FEATURE_MDEV_RENAME help Add support for regular expressions substitutions when renaming device. config FEATURE_MDEV_EXEC bool "Support command execution at device addition/removal" default y depends on FEATURE_MDEV_CONF help This adds support for an optional field to /etc/mdev.conf for executing commands when devices are created/removed. For more information, please see docs/mdev.txt config FEATURE_MDEV_LOAD_FIRMWARE bool "Support loading of firmware" default y depends on MDEV help Some devices need to load firmware before they can be usable. These devices will request userspace look up the files in /lib/firmware/ and if it exists, send it to the kernel for loading into the hardware. config MESG bool "mesg (1.4 kb)" default y help Mesg controls access to your terminal by others. It is typically used to allow or disallow other users to write to your terminal config FEATURE_MESG_ENABLE_ONLY_GROUP bool "Enable writing to tty only by group, not by everybody" default y depends on MESG help Usually, ttys are owned by group "tty", and "write" tool is setgid to this group. This way, "mesg y" only needs to enable "write by owning group" bit in tty mode. If you set this option to N, "mesg y" will enable writing by anybody at all. This is not recommended. config MKE2FS bool "mke2fs (10 kb)" default y select PLATFORM_LINUX help Utility to create EXT2 filesystems. config MKFS_EXT2 bool "mkfs.ext2 (10 kb)" default y select PLATFORM_LINUX help Alias to "mke2fs". config MKFS_MINIX bool "mkfs.minix (10 kb)" default y select PLATFORM_LINUX help The minix filesystem is a nice, small, compact, read-write filesystem with little overhead. If you wish to be able to create minix filesystems this utility will do the job for you. config FEATURE_MINIX2 bool "Support Minix fs v2 (fsck_minix/mkfs_minix)" default y depends on FSCK_MINIX || MKFS_MINIX help If you wish to be able to create version 2 minix filesystems, enable this. If you enabled 'mkfs_minix' then you almost certainly want to be using the version 2 filesystem support. config MKFS_REISER bool "mkfs_reiser" default n select PLATFORM_LINUX help Utility to create ReiserFS filesystems. Note: this applet needs a lot of testing and polishing. config MKDOSFS bool "mkdosfs (7.2 kb)" default y select PLATFORM_LINUX help Utility to create FAT32 filesystems. config MKFS_VFAT bool "mkfs.vfat (7.2 kb)" default y select PLATFORM_LINUX help Alias to "mkdosfs". config MKSWAP bool "mkswap (6.3 kb)" default y help The mkswap utility is used to configure a file or disk partition as Linux swap space. This allows Linux to use the entire file or partition as if it were additional RAM, which can greatly increase the capability of low-memory machines. This additional memory is much slower than real RAM, but can be very helpful at preventing your applications being killed by the Linux out of memory (OOM) killer. Once you have created swap space using 'mkswap' you need to enable the swap space using the 'swapon' utility. config FEATURE_MKSWAP_UUID bool "UUID support" default y depends on MKSWAP help Generate swap spaces with universally unique identifiers. config MORE bool "more (7 kb)" default y help more is a simple utility which allows you to read text one screen sized page at a time. If you want to read text that is larger than the screen, and you are using anything faster than a 300 baud modem, you will probably find this utility very helpful. If you don't have any need to reading text files, you can leave this disabled. config MOUNT bool "mount (23 kb)" default y select PLATFORM_LINUX help All files and filesystems in Unix are arranged into one big directory tree. The 'mount' utility is used to graft a filesystem onto a particular part of the tree. A filesystem can either live on a block device, or it can be accessible over the network, as is the case with NFS filesystems. config FEATURE_MOUNT_FAKE bool "Support -f (fake mount)" default y depends on MOUNT help Enable support for faking a file system mount. config FEATURE_MOUNT_VERBOSE bool "Support -v (verbose)" default y depends on MOUNT help Enable multi-level -v[vv...] verbose messages. Useful if you debug mount problems and want to see what is exactly passed to the kernel. config FEATURE_MOUNT_HELPERS bool "Support mount helpers" default n depends on MOUNT help Enable mounting of virtual file systems via external helpers. E.g. "mount obexfs#-b00.11.22.33.44.55 /mnt" will in effect call "obexfs -b00.11.22.33.44.55 /mnt" Also "mount -t sometype [-o opts] fs /mnt" will try "sometype [-o opts] fs /mnt" if simple mount syscall fails. The idea is to use such virtual filesystems in /etc/fstab. config FEATURE_MOUNT_LABEL bool "Support specifying devices by label or UUID" default y depends on MOUNT select VOLUMEID help This allows for specifying a device by label or uuid, rather than by name. This feature utilizes the same functionality as blkid/findfs. config FEATURE_MOUNT_NFS bool "Support mounting NFS file systems on Linux < 2.6.23" default n depends on MOUNT select FEATURE_SYSLOG help Enable mounting of NFS file systems on Linux kernels prior to version 2.6.23. Note that in this case mounting of NFS over IPv6 will not be possible. Note that this option links in RPC support from libc, which is rather large (~10 kbytes on uclibc). config FEATURE_MOUNT_CIFS bool "Support mounting CIFS/SMB file systems" default y depends on MOUNT help Enable support for samba mounts. config FEATURE_MOUNT_FLAGS depends on MOUNT bool "Support lots of -o flags" default y help Without this, mount only supports ro/rw/remount. With this, it supports nosuid, suid, dev, nodev, exec, noexec, sync, async, atime, noatime, diratime, nodiratime, loud, bind, move, shared, slave, private, unbindable, rshared, rslave, rprivate, and runbindable. config FEATURE_MOUNT_FSTAB depends on MOUNT bool "Support /etc/fstab and -a (mount all)" default y help Support mount all and looking for files in /etc/fstab. config FEATURE_MOUNT_OTHERTAB depends on FEATURE_MOUNT_FSTAB bool "Support -T " default y help Support mount -T (specifying an alternate fstab) config MOUNTPOINT bool "mountpoint (4.9 kb)" default y help mountpoint checks if the directory is a mountpoint. config NOLOGIN bool "nologin" default y depends on FEATURE_SH_EMBEDDED_SCRIPTS help Politely refuse a login config NOLOGIN_DEPENDENCIES bool "Enable dependencies for nologin" default y depends on NOLOGIN select CAT select ECHO select SLEEP help nologin is implemented as a shell script. It requires the following in the runtime environment: cat echo sleep If you know these will be available externally you can disable this option. config NSENTER bool "nsenter (6.5 kb)" default y select PLATFORM_LINUX help Run program with namespaces of other processes. config PIVOT_ROOT bool "pivot_root (1.1 kb)" default y select PLATFORM_LINUX help The pivot_root utility swaps the mount points for the root filesystem with some other mounted filesystem. This allows you to do all sorts of wild and crazy things with your Linux system and is far more powerful than 'chroot'. Note: This is for initrd in linux 2.4. Under initramfs (introduced in linux 2.6) use switch_root instead. config RDATE bool "rdate (5.6 kb)" default y help The rdate utility allows you to synchronize the date and time of your system clock with the date and time of a remote networked system using the RFC868 protocol, which is built into the inetd daemon on most systems. config RDEV bool "rdev (1.8 kb)" default y help Print the device node associated with the filesystem mounted at '/'. config READPROFILE bool "readprofile (7.1 kb)" default y #select PLATFORM_LINUX help This allows you to parse /proc/profile for basic profiling. config RENICE bool "renice (4.2 kb)" default y help Renice alters the scheduling priority of one or more running processes. config REV bool "rev (4.4 kb)" default y help Reverse lines of a file or files. config RTCWAKE bool "rtcwake (6.8 kb)" default y select PLATFORM_LINUX help Enter a system sleep state until specified wakeup time. config SCRIPT bool "script (8.6 kb)" default y help The script makes typescript of terminal session. config SCRIPTREPLAY bool "scriptreplay (2.4 kb)" default y help This program replays a typescript, using timing information given by script -t. config SETARCH bool "setarch (3.6 kb)" default y select PLATFORM_LINUX help The linux32 utility is used to create a 32bit environment for the specified program (usually a shell). It only makes sense to have this util on a system that supports both 64bit and 32bit userland (like amd64/x86, ppc64/ppc, sparc64/sparc, etc...). config LINUX32 bool "linux32 (3.3 kb)" default y select PLATFORM_LINUX help Alias to "setarch linux32". config LINUX64 bool "linux64 (3.3 kb)" default y select PLATFORM_LINUX help Alias to "setarch linux64". config SETPRIV bool "setpriv (6.6 kb)" default y select PLATFORM_LINUX select LONG_OPTS help Run a program with different Linux privilege settings. Requires kernel >= 3.5 config FEATURE_SETPRIV_DUMP bool "Support dumping current privilege state" default y depends on SETPRIV help Enables the "--dump" switch to print out the current privilege state. This is helpful for diagnosing problems. config FEATURE_SETPRIV_CAPABILITIES bool "Support capabilities" default y depends on SETPRIV help Capabilities can be used to grant processes additional rights without the necessity to always execute as the root user. Enabling this option enables "--dump" to show information on capabilities. config FEATURE_SETPRIV_CAPABILITY_NAMES bool "Support capability names" default y depends on SETPRIV && FEATURE_SETPRIV_CAPABILITIES help Capabilities can be either referenced via a human-readble name, e.g. "net_admin", or using their index, e.g. "cap_12". Enabling this option allows using the human-readable names in addition to the index-based names. config SETSID bool "setsid (3.6 kb)" default y help setsid runs a program in a new session config SWAPON bool "swapon (15 kb)" default y select PLATFORM_LINUX help Once you have created some swap space using 'mkswap', you also need to enable your swap space with the 'swapon' utility. The 'swapoff' utility is used, typically at system shutdown, to disable any swap space. If you are not using any swap space, you can leave this option disabled. config FEATURE_SWAPON_DISCARD bool "Support discard option -d" default y depends on SWAPON help Enable support for discarding swap area blocks at swapon and/or as the kernel frees them. This option enables both the -d option on 'swapon' and the 'discard' option for swap entries in /etc/fstab. config FEATURE_SWAPON_PRI bool "Support priority option -p" default y depends on SWAPON help Enable support for setting swap device priority in swapon. config SWAPOFF bool "swapoff (14 kb)" default y select PLATFORM_LINUX config FEATURE_SWAPONOFF_LABEL bool "Support specifying devices by label or UUID" default y depends on SWAPON || SWAPOFF select VOLUMEID help This allows for specifying a device by label or uuid, rather than by name. This feature utilizes the same functionality as blkid/findfs. config SWITCH_ROOT bool "switch_root (5.5 kb)" default y select PLATFORM_LINUX help The switch_root utility is used from initramfs to select a new root device. Under initramfs, you have to use this instead of pivot_root. (Stop reading here if you don't care why.) Booting with initramfs extracts a gzipped cpio archive into rootfs (which is a variant of ramfs/tmpfs). Because rootfs can't be moved or unmounted*, pivot_root will not work from initramfs. Instead, switch_root deletes everything out of rootfs (including itself), does a mount --move that overmounts rootfs with the new root, and then execs the specified init program. * Because the Linux kernel uses rootfs internally as the starting and ending point for searching through the kernel's doubly linked list of active mount points. That's why. config TASKSET bool "taskset (4.2 kb)" default y help Retrieve or set a processes's CPU affinity. This requires sched_{g,s}etaffinity support in your libc. config FEATURE_TASKSET_FANCY bool "Fancy output" default y depends on TASKSET help Needed for machines with more than 32-64 CPUs: affinity parameter 0xHHHHHHHHHHHHHHHHHHHH can be arbitrarily long in this case. Otherwise, it is limited to sizeof(long). config UEVENT bool "uevent (3.1 kb)" default y select PLATFORM_LINUX help uevent is a netlink listener for kernel uevent notifications sent via netlink. It is usually used for dynamic device creation. config UMOUNT bool "umount (5.1 kb)" default y select PLATFORM_LINUX help When you want to remove a mounted filesystem from its current mount point, for example when you are shutting down the system, the 'umount' utility is the tool to use. If you enabled the 'mount' utility, you almost certainly also want to enable 'umount'. config FEATURE_UMOUNT_ALL bool "Support -a (unmount all)" default y depends on UMOUNT help Support -a option to unmount all currently mounted filesystems. config UNSHARE bool "unshare (7.2 kb)" default y depends on !NOMMU select PLATFORM_LINUX select LONG_OPTS help Run program with some namespaces unshared from parent. config WALL bool "wall (2.6 kb)" default y depends on FEATURE_UTMP help Write a message to all users that are logged in. comment "Common options for mount/umount" depends on MOUNT || UMOUNT config FEATURE_MOUNT_LOOP bool "Support loopback mounts" default y depends on MOUNT || UMOUNT help Enabling this feature allows automatic mounting of files (containing filesystem images) via the linux kernel's loopback devices. The mount command will detect you are trying to mount a file instead of a block device, and transparently associate the file with a loopback device. The umount command will also free that loopback device. You can still use the 'losetup' utility (to manually associate files with loop devices) if you need to do something advanced, such as specify an offset or cryptographic options to the loopback device. (If you don't want umount to free the loop device, use "umount -D".) config FEATURE_MOUNT_LOOP_CREATE bool "Create new loopback devices if needed" default y depends on FEATURE_MOUNT_LOOP help Linux kernels >= 2.6.24 support unlimited loopback devices. They are allocated for use when trying to use a loop device. The loop device must however exist. This feature lets mount to try to create next /dev/loopN device if it does not find a free one. config FEATURE_MTAB_SUPPORT bool "Support old /etc/mtab file" default n depends on MOUNT || UMOUNT select FEATURE_MOUNT_FAKE help Historically, Unix systems kept track of the currently mounted partitions in the file "/etc/mtab". These days, the kernel exports the list of currently mounted partitions in "/proc/mounts", rendering the old mtab file obsolete. (In modern systems, /etc/mtab should be a symlink to /proc/mounts.) The only reason to have mount maintain an /etc/mtab file itself is if your stripped-down embedded system does not have a /proc directory. If you must use this, keep in mind it's inherently brittle (for example a mount under chroot won't update it), can't handle modern features like separate per-process filesystem namespaces, requires that your /etc directory be writable, tends to get easily confused by --bind or --move mounts, won't update if you rename a directory that contains a mount point, and so on. (In brief: avoid.) About the only reason to use this is if you've removed /proc from your kernel. source util-linux/volume_id/Config.in endmenu