X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev.8;h=79b74bf659736f850d368aac0e9a682d0068728a;hp=771ecfa454915c2fd3b4eb13478837ff853923f9;hb=98b88dbf704a1376ee4c79051086089adde5d626;hpb=d3db5e5e405b81ae094a5b0fab53d37b2356514c;ds=sidebyside diff --git a/udev.8 b/udev.8 index 771ecfa45..79b74bf65 100644 --- a/udev.8 +++ b/udev.8 @@ -2,66 +2,110 @@ .SH NAME udev \- Linux configurable dynamic device naming support .SH SYNOPSIS -.B udev +.BI udev " hotplug-subsystem" .SH "DESCRIPTION" .B udev creates or removes device node files usually located in the /dev directory. +Its goal is to provide a dynamic device directory that contains only the files +for devices that are actually present. +.P As part of the .B hotplug subsystem, .B udev -is exectuted if a kernel device is added or removed from the system. -.P +is executed if a kernel device is added or removed from the system. On device creation, .B udev -reads the sysfs directory of the given device, to collect device attributes +reads the sysfs directory of the given device to collect device attributes like label, serial number or bus device number. -These attributes are passed as a key to the namedev subsystem -to receive a unique name for device file creation. -namedev maintains a database for devices present on the system. -.P +These attributes are treated as a key +to determine a unique name for device file creation. +.B udev +maintains a database for devices present on the system. +.br On device removal, .B udev -queries the namedev database for the name of the device file to delete. -.P -namedev expects its configuration at -.I /etc/udev/namedev.config. +queries the internal database for the name of the device file to be deleted. +.SH "CONFIGURATION" +.B udev +expects its configuration at +.I /etc/udev/udev.config. The file consists of a set of lines. All empty lines and lines beginning with a '#' will be ignored. .br -Every line defines the mapping between device attributes and the name of -the device file. It starts with a keyword defining the method for -overriding the default kernel naming scheme, followed by a list -of keys and ends with the definition of the filename for the device. +Every line defines the mapping between device attributes and the device file +name. It starts with a keyword defining the method used to match, followed by +one ore more keys to compare and the filename for the device. If no matching +configuration is found, the default kernel device name is used. +.P +The line format is: +.RS +.sp +.I method, key,[key,...] name +.sp +.RE +where valid methods with corresponding keys are: .TP .B LABEL device label or serial number, like USB serial number, SCSI UUID or file system label +.br +keys: \fBBUS\fP, \fIsysfs_attribute\fP .TP .B NUMBER device number on the bus, like PCI bus id +.br +keys: \fBBUS\fP, \fBID\fP .TP .B TOPOLOGY device position on bus, like physical port of USB device +.br +keys: \fBBUS\fP, \fBPLACE\fP .TP .B REPLACE string replacement of the kernel device name +.br +key: \fBKERNEL_NAME\fP +.TP +.B CALLOUT +calling external program, that returns a string to match +.br +keys: \fBBUS\fP, \fBPROGRAM\fP, \fBID\fP .P -If no matching configuration is found, the default kernel device name is used. -.SH "EXAMPLE" +A sample \fIudev.conf\fP might look like this: +.sp .nf # USB printer to be called lp_color LABEL, BUS="usb", serial="W09090207101241330", NAME="lp_color" # sound card with PCI bus id 00:0b.0 to be called dsp -NUMBER, BUS="pci", id="00:0b.0", NAME="dsp" +NUMBER, BUS="pci", ID="00:0b.0", NAME="dsp" # USB mouse at third port of the second hub to be called mouse1 -TOPOLOGY, BUS="usb", place="2.3", NAME="mouse1" +TOPOLOGY, BUS="usb", PLACE="2.3", NAME="mouse1" # ttyUSB1 should always be called pda REPLACE, KERNEL="ttyUSB1", NAME="pda" + +# if /sbin/scsi_id returns "OEM 0815" device will be called disk1 +CALLOUT, PROGRAM="/sbin/scsi_id" BUS="scsi", ID="OEM 0815" NAME="disk1" +.fi +.P +Permissions and ownership for the created device files may specified at +.I /etc/udev/udev.permissions. +The file consists of a set of lines. All empty lines and +lines beginning with a '#' will be ignored. +.br +Every line lists a device name followed by owner, group and permission mode. All values are separated by colons. +.sp +A sample \fIudev.permissions\fP might look like this: +.sp +.nf +#name:user:group:mode +ttyUSB1:root:uucp:0666 +dsp1:::0666 .fi + .SH "FILES" .nf .ft B @@ -72,11 +116,12 @@ REPLACE, KERNEL="ttyUSB1", NAME="pda" .fi .LP .SH "SEE ALSO" -.B hotplug (8) +.BR hotplug (8) .PP The .I http://linux-hotplug.sourceforge.net/ web site. .SH AUTHORS -udev was developed by Greg Kroah-Hartman with much help from +.B udev +was developed by Greg Kroah-Hartman with much help from Dan Stekloff and many others.