# # For a description of the syntax of this configuration file, # see scripts/kbuild/config-language.txt. # menu "Linux System Utilities" config DMESG bool "dmesg" default n 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 dmesg 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 FBSET bool "fbset" default n 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 "Turn on extra fbset options" default n 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 "Turn on fbset readmode support" default n 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 FDFLUSH bool "fdflush" default n 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 FDFORMAT bool "fdformat" default n help fdformat is used to low-level format a floppy disk. config FDISK bool "fdisk" default n 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 help Enable this option to support large disks > 4GB. 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_FDISK_ADVANCED bool "Support expert mode" default n 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 FREERAMDISK bool "freeramdisk" default n 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" default n 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 MKFS_MINIX bool "mkfs_minix" default n 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. comment "Minix filesystem support" depends on FSCK_MINIX || MKFS_MINIX 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 GETOPT bool "getopt" default n 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 HEXDUMP bool "hexdump" default n 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 HWCLOCK bool "hwclock" default n 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_LONG_OPTIONS bool "Support long options (--hctosys,...)" default n depends on HWCLOCK && GETOPT_LONG help By default, the hwclock utility only uses short options. If you are overly fond of its long options, such as --hctosys, --utc, etc) then enable this option. config FEATURE_HWCLOCK_ADJTIME_FHS bool "Use FHS /var/lib/hwclock/adjtime" default y 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. http://www.pathname.com/fhs/pub/fhs-2.3.html#VARLIBHWCLOCKSTATEDIRECTORYFORHWCLO config IPCRM bool "ipcrm" default n select FEATURE_SUID 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" default n select FEATURE_SUID help The ipcs utility is used to provide information on the currently allocated System V interprocess (IPC) objects in the system. config LOSETUP bool "losetup" default n 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 MDEV bool "mdev" default n 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 n 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_EXEC bool "Support command execution at device addition/removal" default n 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 firmwares" default n 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 MKSWAP bool "mkswap" default n 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_V0 bool "version 0 support" default n depends on MKSWAP # depends on MKSWAP && DEPRECATED help Enable support for the old v0 style. If your kernel is older than 2.1.117, then v0 support is the only option. config MORE bool "more" default n 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 FEATURE_USE_TERMIOS bool "Use termios to manipulate the screen" default y depends on MORE help This option allows utilities such as 'more' and 'top' to determine the size of the screen. If you leave this disabled, your utilities that display things on the screen will be especially primitive and will be unable to determine the current screen size, and will be unable to move the cursor. config MOUNT bool "mount" default n 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. Most people using BusyBox will also want to enable the 'mount' utility. config FEATURE_MOUNT_NFS bool "Support mounting NFS file systems" default n depends on MOUNT select FEATURE_HAVE_RPC select FEATURE_SYSLOG help Enable mounting of NFS file systems. config FEATURE_MOUNT_CIFS bool "Support mounting CIFS/SMB file systems" default n depends on MOUNT help Enable support for samba mounts. config FEATURE_MOUNT_FLAGS depends on MOUNT bool "Support lots of -o flags in mount" 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" default y help Support mount all and looking for files in /etc/fstab. config PIVOT_ROOT bool "pivot_root" default n 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" default n 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 READPROFILE bool "readprofile" default n help This allows you to parse /proc/profile for basic profiling. config SETARCH bool "setarch" default n 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 SWAPONOFF bool "swaponoff" default n help This option enables both the 'swapon' and the 'swapoff' utilities. 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 SWITCH_ROOT bool "switch_root" default n 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 UMOUNT bool "umount" default n 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 "umount -a option" default n depends on UMOUNT help Support -a option to unmount all currently mounted filesystems. comment "Common options for mount/umount" depends on MOUNT || UMOUNT config FEATURE_MOUNT_LOOP bool "Support loopback mounts" default n 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_MTAB_SUPPORT bool "Support for the old /etc/mtab file" default n depends on MOUNT || UMOUNT 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 writeable, 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. endmenu