MAKEDEV (8) Linux Manual Page

MAKEDEV – create devices

Synopsis

cd /dev; ./MAKEDEV [ -n ] [ -v ] [ update ]
cd /dev; ./MAKEDEV [ -n ] [ -v ] [ generic ] [ local ] [ group-keyword … device … ]
cd /dev; ./MAKEDEV [ -n ] [ -v ] [ -d ] device …

Description

MAKEDEV is a script that will create the devices in /dev used to interface with drivers in the kernel.

Note that programs giving the error “ENOENT: No such file or directory” normally means that the device file is missing, whereas “ENODEV: No such device” normally means the kernel does not have the driver configured or loaded.

Options

-n: Do not actually update the devices, just print the actions that would be performed.
-d: Delete the devices. The main use for this flag is by MAKEDEV itself.
-v: Be verbose. Print out the actions as they are performed. This is the same output as produced by -n.

Customisation

Since there is currently no standardisation in what names are used for system users and groups, it is possible that you may need to modify MAKEDEV to reflect your site’s settings. Near the top of the file is a mapping from device type to user, group and permissions (e.g. all CD-ROM devices are set from the $cdrom variable). If you wish to change the defaults, this is the section to edit.

General Options

update: This only works on kernels which have /proc/interrupts (introduced during 1.1.x). This file is scanned to see what devices are currently configured into the kernel, and this is compared with the previous settings stored in the file called DEVICES. Devices which are new since then or have a different major number are created, and those which are no longer configured are deleted.
generic: Create a generic subset of devices. This subset consists of the standard devices, plus floppy drives, various hard drives, CD-ROM drives, pseudo-terminals, console devices, basic serial devices, busmice, audio devices, video framebuffers, printer ports, and some specialized devices. The generic subset varies somewhat according to architecture; see the /dev/MAKEDEV script itself for details.
local: This simply runs MAKEDEV.local. This is a script that can create any local devices.

Device Groups

MAKEDEV creates groups of devices when passed keywords for the group. Each listing below shows the MAKEDEV keyword and then lists the devices which will be created. Many devices can also be specified individually.

Standard Devices

std: Creates this group of standard devices: mem for access to physical memory, kmem for access to kernel virtual memory, null the null device (infinite sink), port for access to I/O ports, zero the null byte source (infinite source), core, a symlink to /proc/kcore (for kernel debugging), full which always returns ENOSPACE on write, random and urandom random byte generators, and tty to access the controlling tty of a process. The loopback disk devices loop0 through loop7 are also created in the std group. These allow you to use a regular file as a block device. A filesystem image can be mounted, and used as though it were a filesystem on a partition or other block device. loop may also be used as a separate keyword to create the 8 loop devices. Finally, the ram group of memory devices is also created by the std keyword (see below).

Memory Devices

ram: This is the keyword used to generate the ramdisk devices ram{0..16} and the ram symlink. This group does not include initrd.
initrd: Ramdisk which has been pre-initialized by a bootloader. initrd is not created in the ram group; it must be specifically included in the command line if you want it to be created.
cpu or microcode: Creates the CPU microcode update interface in the cpu/ folder, with devices microcode, and subfolders {0..3} each containing devices msr and cpuid.
rom: Creates the rom{0..7} rrom{0..7} flaxh{0..7} and rflash{0..7} flash memory card devices. rrom and rflash devices are read-only.

Console Devices

console: This keyword creates virtual consoles; tty{0..63} devices, the corresponding vcs and vcsa devices which are used to generate screen-dumps, and the console device itself plus appropriate symlinks. To create the console device alone, use consoleonly. The device tty0 is the currently active virtual console. The console device serves the same function.

Pseudo Terminals

pty: This keyword creates the Pseudo-TTY masters pty{a..e,p..z} and corresponding tty{a..e,p..z} devices, along with ptmx. Each possible argument will create a bank of 16 master and slave pairs. The master pseudo-terminals are pty{p..s}{0..9a..f}, and the slaves are tty{p..s}{0..9a..f}.

Serial Devices

ttyS{0..63}: Standard serial ports. There is no group keyword, you must specify these individually. However ttyS{0..3} are created under the generic option for most architectures.
cyclades or ttyC: Creates Cyclades ports ttyC{0..31}.
digi or ttyD: Creates Digiboard serial card ports ttyD{0..15}.
stallion or ttyE: Creates Stallion devices ttyE{0..255} and staliomem{0..3}.
computone or ttyF: Creates CompuTone serial card ports ttyH{0..255} and special devices ip2ipl{0,4,8,12} and ip2stat{1,5,9,13}.
chase or ttyH: Creates Chase serial card ports ttyH{0..15}.
isdnmodem or ttyI: Creates isdn4linux virtual modem ports ttyI{0..63}.
isdn-tty: Also creates isdn4linux virtual modem ports ttyI{0..7}.
isdnbri: Creates ISDN BRI driver devices isdn{0..63} isdnctrl{0..63} ippp{0..63} and isdninfo.
isdn-io: Also creates ISDN BRI driver devices isdn{0..7} isdnctrl{0..7} ippp{0..7} and isdninfo. The isdn-ippp keyword can be used separately to create only the ippp{0..7} devices.
ppp: Creates a device independent PPP interface.
dcbri: Creates Spellcaster DataComm/BRI ISDN card devices dcbri{0..3}.
riscom or ttyL: Creates Riscom serial card ports ttyL{0..15}.
PAM or ttyM: Creates PAM multimodem (or ISI serial card) ports ttyM{0..15}.
ESP or ttyP: Creates ESP ports ttyP{0..4}.
rocketport or ttyR: Creates Rocketport devices ttyR{0..63}.
ttyV: Creates Comtrol VS-1000 serial controller ports ttyV{0..15}.
specialixIO8 or ttyW: Creates Specialix IO8+ ports ttyW{0..15}.
specialix or ttyX: Creates Specialix ports ttyX{0..15}.
i2c: Creates i2c{0..7} devices for the I2C bus interface.
tlk: Philips SAA5249 Teletext signal decoder {2.6} ports tlk{0..3}.

Parallel Ports

lp: Creates the standard parallel ports lp0, lp1, and lp2 normally used for printers. These correspond to ports at 0x3bc, 0x378 and 0x278. Hence, on some machines, the first printer port may actually be lp1.
par: Alternative to lp. The same ports are created, but are named par{0..2} instead of lp{0..2}.
parport: Creates raw parallel ports parport0, parport1, and parport2.
slm: Creates the Atari SLM ACSI laser printer (68k/Atari) ports slm{0..3}.
pg: Parallel port generic ATAPI interface (devices pg{0..3}.
paride: Parallel port IDE disk devices pd{a..d} with 15 partitions on each. Also creates pcd{0..3} and pf{0..3}.

Other Bus Ports

netlink or tap: Creates NetLink devices route skip fwmonitor and tap{0..15} Ethertap devices. The tapx virtual ethernet device was designed as low level kernel support for Ethernet tunneling. Userland application can write Ethernet frame to /dev/tapX and the kernel will receive this frame from tapX interface. Every frame the kernel writes to a tapX interface can be read by a userland application from the corresponding /dev/tapX device.
enskip: ENskip kernel encryption package.
qng: ComScire Quantum Noise Generator.
ipsec: The Free S/WAN implementation of IPSEC.
adb: On powerpc, creates adb for the Apple Data Bus and adbmouse. On m68k, adb creates the ACSI disk device adb and partitions adb1 through adb15.
hamradio: Creates the scc{0..7} and bc{0..3} device groups.
comx: Creates COMX devices comx{0..4}.
irda: Creates IrCOMM devices (IrDA serial/parallel emulation) ircomm0 ircomm1 irlpt0 and irlpt1.
comedi: Control and Measurement devices comedi{0..3}.

Mouse Devices

busmice: This keyword creates the following devices: logibm (Logitech bus mouse), psaux (PS/2-style mouse), inportbm (Microsoft Inport bus mouse) and atibm (ATI XL bus mouse) and jbm (J-mouse).
m68k-mice: Creates mouse devices for the m68k architecture, including: amigamouse, amigamouse1, atarimouse and adbmouse.
input: On powerpc, this keyword creates the input folder which groups input devices mice, mouse{0..3}, event{0..3}, and js{0..3} (joystick), and creates these devices inside.

Joystick Devices

js: Joystick. Creates js0 and js1.
djs: Digital joystick. Creates djs0 and djs1.

Usb Devices

usb: USB is a general purpose I/O bus which can serve many purposes. The usb keyword creates a usb folder, and devices in the folder: lp{0..15} (printer), mouse{0..15} (USB connected mice), ez{0..15} (firmware loaders) scanner{0..15} (scanner interfaces), ttyACM{0..15} and ttyUSB{0..15} (dialout devices), and rio500 the Diamond Rio 500 device.

Disk Devices

fd{0..7}: Floppy disk devices. The device fdx is the device which autodetects the format, and the additional devices are fixed format (whose size is indicated in the name). The other devices are named as fdx{dqhu}n. The single letter (d, q, hor u) signifies the type of drive: 5.25" Double Density (d), 5.25" Quad Density (q), 5.25" High Density (h) or 3.5" (any model, u). The number n represents the capacity of that format in K. Thus the standard formats are fdxd360, fdxh1200, fdx720, fdx1440, and fdx2880.; For more information see Alain Knaff’s fdutils package.; Devices fd0* through fd3* are floppy disks on the first controller, and devices fd4* through fd7* are floppy disks on the second controller.
fd{0..7}-bare: Creates just the autodetecting floppy device specified, without the fixed format devices.
hd{a..l}: AT (ide) hard disks. The device hdx provides access to the whole disk, with the partitions being hdx{1..63}. For i386, the four primary partitions are hdx1 through hdx4, with the logical partitions being numbered from hdx5 though hdx20. (A primary partition can be made into an extended partition, which can hold 4 logical partitions). Other architectures may not differentiate partition types. By default, devices for 20 logical partitions are made. The kernel supports up to 63 partitions per device.; Drives hda and hdb are the two on the primary controller hdc and hdd are the two drives on the secondary controller. These devices can also be used to access IDE CDROMs. Additional devices hd{e..l} can be created.
xd{a..d}: XT hard disks. Partitions are the same as IDE disks, except only 8 partitions are created.
sd{a..h}: SCSI hard disks. The partitions are similar to the IDE disks, but there is a limit of 11 logical partitions sdx5 through sdx15, to allow there to be 8 SCSI disks on a system (addresses 0 through 7).
sd{i..z}: and sd{a..d}{a..z} The kernel (and MAKEDEV) can handle up to 128 SCSI disks (up to sddx). 15 partition devices are created for each.
eda edb: MCA ESDI hard disk. Partitions are handled the same as hd.
dasd{a..z}: Direct Access Storage Devices for the s390 architecture. Currently only one device partition is created (for example, dasda1).
ada{a..p}: ACSI disk (68k/Atari). 15 partitions are created for each.
dac960.{0..7}: Mylex DAC960 PCI RAID controller. For this device, an rd directory is created. 32 logical devices cxd{0..31} are created for each unit x specified, each with 7 partitions cxd{0..31}p{1..7}. The dac960 keyword will create all 7 units at once.
dpti: Adaptec I2O RAID and DPT SmartRAID V I2O controllers. Creates 7 devices for handling up to 7 controllers.
ataraid.{0..7}: Obsolete, device not in current devices.txt. For this device, an ataraid directory is created. dx is created for each unit x specified, and 15 partitions dxp{1..15}. The ataraid keyword will create all 7 units at once.
i2o.hd{a..d}{a..z}: I2O based harddisk drives. Device nodes are located in the i2o directory. The filename is followed by a number that specifies the partition on each disk. The numbers are handled the same as hd.
ida.{0..7}: Compaq Intelligent Drive Array. For this device, an ida directory is created. 16 logical devices cxd{0..15} are created for each unit x specified, each with 15 partitions cxd{0..15}p{1..15}. The ida keyword will create the first three units.
cciss.{0..7}: Compaq Next Generation Drive Array. For this device, a cciss directory is created. 16 logical devices cxd{0..15} are created for each unit x specified, each with 15 partitions cxd{0..15}p{1..15}. The cciss keyword will create the first three units.
md: Creates Metadisk (RAID) disk array with 16 devices.

Tape Devices

st{0..7}: SCSI tape devices. This creates the rewinding tape device stx and the non-rewinding tape device nstx, for each of modes 0 through 3.
qic: QIC-11, -24, -120, and -150 tapes. The devices created are ntpqic11 tpqic11 ntpqic24 tpqic24 ntpqic120 tpqic120 ntpqic150 and tpqic150 tape devices, along with rmt8, rmt16, tape-d, and tape-reset.
ftape: Floppy driver tapes (QIC-117). There are 4 methods of access depending on
the floppy tape drive. For each of access methods 0, 1, 2 and 3, the devices qftx zqftx and rawqftx (rewinding) and nqftx nzqftx nrawqdtx (non-rewinding) are created. For compatibility, devices ftape and nftape are symlinks to qft0 and nqft0 respectively.
ht0: Creates IDE tape devices ht0 and nht0.
pt{0..3}: Creates parallel port ATAPI tape devices pt{0..3} and npt{0..3}.

Cdrom Devices

sr or scd or scd-all: Creates scd{0..16} SCSI CD players and sr{0..16} symlinks for these devices. cdrom is a symlink which can be created by the user to the active CD device. It is not created by MAKEDEV.
pktcdvd: Provides packet writing devices pktcdvd{0..3} for CD/DVD.
pcd{0..3}: Parallel port ATAPI CD-ROM devices
sonycd: Sony CDU-31a CD-ROM
mcd: Mitsumi CD-ROM
mcdx: Obsolete, device not in current devices.txt.
cdu535: Sony CDU-535 CD-ROM
lmscd: Philips LMS CM-205 CD-ROM. The newer name for this device is cm205, but MAKEDEV creates only lmscd at this time.
cm206cd: Philips LMS CM-206 CD-ROM
bpcd: MicroSolutions BackPack parallel port CD-ROM (Obsolete – use pcd)
sbpcd{0..15}: Matsushita (Panasonic/SoundBlaster) CD-ROM. Units {0..3} are created with the keyword sbpcd.
aztcd: Aztech/Orchid/Okano/Wearnes CD-ROM
gscd: GoldStar CD-ROM
optcd: Optics Storage CD-ROM
sjcd: Sanyo CD-ROM
hitcd: Hitachi CD-ROM

Scanners

logiscan: Logitech ScanMan32 & ScanMan 256.
m105scan: Mustek M105 Handscanner.
ac4096: A4Tek Color Handscanner.

Audio Devices

audio: This creates the audio devices used by the sound driver. These include mixer mixer{1..3} (Mixer controls), sequencer (Audio sequencer), dsp dsp{1..3} (Digital audio), sndstat (Sound card status information), audioctl (SPARC audio control device) and audio audio{1..3} (Sun-compatible digital audio). MIDI devices are midi00 through midi03, midi{0..3}, rmidi{0..3}, smpte{0..3}. In addition, devices mpu401data and mpu401stat are created.
pcaudio: Devices for the PC Speaker sound driver. These are pcmixer, pxsp, and pcaudio.

Video Devices

fb: Creates framebuffer devices fb{0..7}, fb{0..7}current, fb{0..7}autodetect.
fb{0..7}: If the framebuffer number x is specifed, a group of fbxuser{0..7} devices is created.
3dfx: is the 3Dfx Voodoo Graphics device.
agpgart: AGP Graphics Address Remapping Table
video video4linux v4l radio: Each of these keywords produces the same result: Video capture/overlay devices video{0..63}, Radio devices radio{0..63}, Teletext devices vtx{0..31}, and Vertical blank interrupt devices vbi{0..31}. In addition, the winradio0 and winradio1 devices, and vtx and vttuner devices, and symlinks radio video and vbi are created.
srnd: miroMEDIA Surround board devices srnd0 and srnd1.
fgrab: Matrox Meteor frame grabber {2.6}. Creates mmetfgrab, wvisfgrab, iscc0, iscc1, isccctl0, isccctl1, dcxx0, and dcxx1.

Miscellaneous Devices

sg or sg-all: Generic SCSI devices. The devices created are sg0 through sg16. These allow arbitary commands to be sent to any SCSI device, to query information or control SCSI devices that are not disk, tape or CDROM (for example, scanner or writeable CDROM).
fd: To allow an arbitary program to be fed input from file descriptor x, use /dev/fd/x as the file name. This also creates /dev/stdin, /dev/stdout, and /dev/stderr. (Note, these are just symlinks into /proc/self/fd).
ibcs2: Devices socksys spx (and symlinks nfsd XOR) needed by the IBCS2 emulation.
apm: apm_bios Advanced Power Management BIOS device.
dcf: Driver for DCF-77 radio clock.
helloworld: Kernel modules demonstration device. See the modules source.
xfs or arla: Arla XFS network file system.
capi: CAPI 2.0 interface ports capi20{01..20}.
ubd: User-mode block devices ubd{0..255}.
nb{0..7}: Network block devices.
raw: Creates the raw block device interface raw device, the rawctl symlink, and raw{1..8}.
raw1394: IEEE 1394 (Firewire).
misc: This keyword creates all the following devices. You may find the device explanations in other categories in this man page, many under OTHER DEVICES below. logibm, psaux, inportbm, atibm, jbm, amigamouse, atarimouse, sunmouse, amigamouse1, smouse, pc110pad, adbmouse, beep, modreq, watchdog, temperature, hwtrap, exttrp, apm_bios, rtc, openprom, relay8, relay16, msr, pciconf, nvram, hfmodem, led, mergemem, pmu.
Network Devices: Linux used to have devices in /dev for controlling network devices, but that is no longer the case. To see what network devices are known by the kernel, look at /proc/net/dev.

Other Devices

Many of these devices are architecture-specific.
scc: Z8530 HDLC driver (HAM radio)
bc: Baycom radio modem (HAM radio)
cfs0 or cfs or coda: Coda network file system
sunmouse: Sun mouse
smouse: Simple serial mouse driver
pc110pad: IBM PC-110 digitizer pad
vrtpanel: Vr41xx embedded touch panel
vpcmouse: Connectix Virtual PC Mouse
beep: Fancy beep device
modreq: Kernel module load request {2.6}
watchdog: Watchdog timer port
temperature: Machine internal temperature
hwtrap: Hardware fault trap
exttrp: External device trap
rtc: Real Time Clock
efirtc: Real Time Clock
openprom: SPARC OpenBoot PROM
relay8: Berkshire Products Octal relay card
relay16: Berkshire Products ISO-16 relay card
msr: x86 model-specific registers {2.6}
pciconf: PCI configuration space
nvram: Non-volatile configuration RAM
hfmodem: Soundcard shortwave modem control {2.6}
graphics: Linux/SGI graphics device
opengl: Linux/SGI OpenGL pipe
gfx: Linux/SGI graphics effects device
lcd: Front panel LCD display
led: Front panel LEDs
mergemem: Memory merge device
pmu: Macintosh PowerBook power manager
isictl: MultiTech ISICom serial control
ac: Applicom Intl Profibus card
nwbutton: Netwinder external button
nwdebug: Netwinder debug interface
nwflash: Netwinder flash memory
userdma: User-space DMA access
smbus: System Management Bus
lik: Logitech Internet Keyboard
ipmo: Intel Intelligent Platform Management
vmmon: VMWare virtual machine monitor
tcldrv: Technology Concepts serial control
specialix_sxctl: Specialix serial control
specialix_rioctl: Specialix RIO serial control
smapi or thinkpad: IBM Thinkpad smapi device, and a symlink thinkpad.
srripc: QNX4 API IPC manager
usemaclone: Semaphore clone device
ipmi or ipmikcs: Intelligent Platform Management
uctrl: SPARCbook 3 microcontroller
gtrsc: Gorgy Timing radio clock
cbm: Serial CBM bus
jsflash: JavaStation OS flash SIMM
xsvc: High-speed shared-mem/semaphore service
vrbuttons: Vr41xx button input device
toshiba: Toshiba laptop SMM support
perfctr: Performance-monitoring counters
intel_rng: Intel i8x0 random number generator
atomicps: Atomic shapshot of process state data
irnet: IrNET device
smbusbios: SMBus BIOS
ussp_ctl: User space serial port control
crash: Mission Critical Linux crash dump facility
nas_xbus: NAS xbus LCD/buttons access
d7s: SPARC 7-segment display
zkshim: Zero-Knowledge network shim control
sexec: Signed executable interface
kchuid: Inter-process chuid control
mptctl: Message passing technology (MPT) control
button/gulpb: Transmeta GULP-B buttons
compaq/cpqphpc: Compaq PCI Hot Plug Controller
compaq/cpqrid: Compaq Remote InsightDriver
elographics/e2201: Elographics touchscreen E271-2201
fujitsu/apanel: Fujitsu/Siemens application panel
i2o/ctl: I2O configuration manager
impi/bt: IMPI coprocessor block transfer
impi/smic: IMPI coprocessor stream interface
input/mouse: Linux/SGI Irix emulation mouse
input/keyboard: Linux/SGI Irix emulation keyboard
modems/mwave: MWave modem firmware upload
mvista/hssdsi: Montavista PICMG hot swap system driver
mvista/hasi: Montavista PICMG high availability
net/tun: TAP/TUN network device
ni/natmotn: National Instruments Motion
scanners/cuecat: :CueCat barcode scanner
touchscreen/ucb1x00: UCB 1×00 touchscreen
touchscreen/mk712: MK712 touchscreen
video/em8300: EM8300 DVD decoder control
video/em8300_mv: EM8300 DVD decoder video
video/em8300_ma: EM8300 DVD decoder audio
video/em8300_sp: EM8300 DVD decoder subpicture
watchdogs/{0..3}: Watchdog devices 0 through 3

Author

Nick Holloway, rewritten and updated by Chris Tillman