9 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
10 and non-dracut initramfs image generators need to change the init
11 scripts. Alternatively the udev build needs to move udevd back to
12 /sbin or create a symlink in /sbin, which is not done by default.
14 The path_id, usb_id, input_id tools are built-in commands now and
15 the stand-alone tools do not exist anymore. Static lists of file in
16 initramfs generators need to be updated. For testing, the commands
17 can still be executed standalone with 'udevadm test-builtin <cmd>'.
19 The fusectl filesystem is no longer mounted directly from udev.
20 Systemd systems will take care of mounting fusectl and configfs
21 now. Non-systemd systems need to ship their own rule if they
22 need these filesystems auto-mounted.
24 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
26 The support for 'udevadm trigger --type=failed, and the
27 RUN{fail_event_on_error} attribute was removed.
29 The udev control socket is now created in /run/udev/control
30 and no longer as an abstract namespace one.
32 The rules to create persistent network interface and cdrom link
33 rules automatically in /etc/udev/rules.d/ have been disabled by
34 default. Explicit configuration will be required for these use
35 cases, udev will no longer try to write any persistent system
36 configuration from a device hotplug path.
42 The udev-acl extra is no longer enabled by default now. To enable it,
43 --enable-udev_acl needs to be given at ./configure time. On systemd
44 systems, the udev-acl rules prevent it from running as the functionality
51 Udev now enables kernel media-presence polling if available. Part
52 of udisks optical drive tray-handling moved to cdrom_id: The tray
53 is locked as soon as a media is detected to enable the receiving
54 of media-eject-request events. Media-eject-request events will
57 Libudev enumerate is now able to enumerate a subtree of a given
60 The mobile-action-modeswitch modeswitch tool was deleted. The
61 functionality is provided by usb_modeswitch now.
67 The systemd service files require systemd version 28. The systemd
68 socket activation make it possible now to start 'udevd' and 'udevadm
73 Fix bug in control message handling, which can lead to a failing
74 udevadm control --exit. Thanks to Jürg Billeter for help tracking
81 We require at least Linux kernel 2.6.32 now. Some platforms might
82 require a later kernel that supports accept4() and similar, or
83 need to backport the trivial syscall wiring to the older kernels.
85 The hid2hci tool moved to the bluez package and was removed.
87 Many of the extras can be --enable/--disabled at ./configure
88 time. The --disable-extras option was removed. Some extras have
89 been disabled by default. The current options and their defaults
90 can be checked with './configure --help'.
96 Udev logs a warning now if /run is not writable at udevd
97 startup. It will still fall back to /dev/.udev, but this is
100 The running udev daemon can now cleanly shut down with:
101 udevadm control --exit
103 Udev in initramfs should clean the state of the udev database
104 with: udevadm info --cleanup-db which will remove all state left
105 behind from events/rules in initramfs. If initramfs uses
106 --cleanup-db and device-mapper/LVM, the rules in initramfs need
107 to add OPTIONS+="db_persist" for all dm devices. This will
108 prevent removal of the udev database for these devices.
110 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
111 120 seconds per process. If that timeout is reached the spawned
112 process will be killed. The event timeout can be overwritten with
115 If systemd is used, udev gets now activated by netlink data.
116 Systemd will bind the netlink socket which will buffer all data.
117 If needed, such setup allows a seemless update of the udev daemon,
118 where no event can be lost during a udevd update/restart.
119 Packages need to make sure to: systemctl stop udev.socket udev.service
120 or 'mask' udev.service during the upgrade to prevent any unwanted
121 auto-spawning of udevd.
122 This version of udev conflicts with systemd version below 25. The
123 unchanged service files will not wirk correctly.
129 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
130 /run mountpoint is supposed to be a tmpfs mounted during early boot,
131 available and writable to for all tools at any time during bootup,
132 it replaces /var/run/, which should become a symlink some day.
134 If /run does not exist, or is not writable, udev will fall back using
137 On systemd systems with initramfs and LVM used, packagers must
138 make sure, that the systemd and initramfs versions match. The initramfs
139 needs to create the /run mountpoint for udev to store the data, and
140 mount this tmpfs to /run in the rootfs, so the that the udev database
141 is preserved for the udev version started in the rootfs.
143 The command 'udevadm info --convert-db' is gone. The udev daemon
144 itself, at startup, converts any old database version if necessary.
146 The systemd services files have been reorganized. The udev control
147 socket is bound by systemd and passed to the started udev daemon.
148 The udev-settle.service is no longer active by default. Services which
149 can not handle hotplug setups properly need to actively pull it in, to
150 act like a barrier. Alternatively the settle service can be unconditionally
151 'systemctl'enabled, and act like a barrier for basic.target.
153 The fstab_import callout is no longer built or installed. Udev
154 should not be used to mount, does not watch changes to fstab, and
155 should not mirror fstab values in the udev database.
161 New and updated keymaps.
167 The udev database has changed, After installation of a new udev
168 version, 'udevadm info --convert-db' should be called, to let the new
169 udev/libudev version read the already stored data.
171 udevadm now supports quoting of property values, and prefixing of
173 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
176 MY_DEVNAME='/dev/sda'
180 libudev now supports:
181 udev_device_get_is_initialized()
182 udev_enumerate_add_match_is_initialized()
183 to be able to skip devices the kernel has created , but udev has
186 libudev now supports:
187 udev_device_get_usec_since_initialized()
188 to retrieve the "age" of a udev device record.
190 GUdev supports a more generic GUdevEnumerator class, udev TAG
191 handling, device initialization and timestamp now.
193 The counterpart of /sys/dev/{char,block}/$major:$minor,
194 /dev/{char,block}/$major:$minor symlinks are now unconditionally
195 created, even when no rule files exist.
197 New and updated keymaps.
203 GUdev moved from /usr to /.
213 Persistent network naming rules are disabled inside of Qemu/KVM now.
215 New and updated keymaps.
217 Udev gets unconditionally enabled on systemd installations now. There
218 is no longer the need to to run 'systemctl enable udev.service'.
232 New and fixed keymaps.
234 Install systemd service files if applicable.
240 All distribution specific rules are removed from the udev source tree,
241 most of them are no longer needed. The Gentoo rules which allow to support
242 older kernel versions, which are not covered by the default rules anymore
243 has moved to rules/misc/30-kernel-compat.rules.
249 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
250 was removed from udevd.
252 Udevd now checks the kernel commandline for the following variables:
253 udev.log-priority=<syslog priority>
254 udev.children-max=<maximum number of workers>
255 udev.exec-delay=<seconds to delay the execution of RUN=>
256 to help debuging coldplug setups where the loading of a kernel
257 module crashes the system.
259 The subdirectory in the source tree rules/packages has been renamed to
260 rules/arch, anc contains only architecture specific rules now.
270 Now the udev daemon itself, does on startup:
271 - copy the content of /lib/udev/devices to /dev
272 - create the standard symlinks like /dev/std{in,out,err},
273 /dev/core, /dev/fd, ...
274 - use static node information provided by kernel modules
275 and creates these nodes to allow module on-demand loading
276 - possibly apply permissions to all ststic nodes from udev
277 rules which are annotated to match a static node
279 The default mode for a device node is 0600 now to match the kernel
280 created devtmpfs defaults. If GROUP= is specified and no MODE= is
281 given the default will be 0660.
287 Udev now gradually starts to pass control over the primary device nodes
288 and their names to the kernel, and will in the end only manage the
289 permissions of the node, and possibly create additional symlinks.
290 As a first step NAME="" will be ignored, and NAME= setings with names
291 other than the kernel provided name will result in a logged warning.
292 Kernels that don't provide device names, or devtmpfs is not used, will
293 still work as they did before, but it is strongly recommended to use
294 only the same names for the primary device node as the recent kernel
295 provides for all devices.
299 Fix broken firmware loader search path.
305 "udevadm trigger" defaults to "change" events now instead of "add"
306 events. The "udev boot script" might need to add "--action=add" to
307 the trigger command if not already there, in case the initial coldplug
308 events are expected as "add" events.
310 The option "all_partitons" was removed from udev. This should not be
311 needed for usual hardware. Udev can not safely make assumptions
312 about non-existing partition major/minor numbers, and therefore no
313 longer provide this unreliable and unsafe option.
315 The option "ignore_remove" was removed from udev. With devtmpfs
316 udev passed control over device nodes to the kernel. This option
317 should not be needed, or can not work as advertised. Neither
318 udev nor the kernel will remove device nodes which are copied from
319 the /lib/udev/devices/ directory.
321 All "add|change" matches are replaced by "!remove" in the rules and
322 in the udev logic. All types of events will update possible symlinks
323 and permissions, only "remove" is handled special now.
325 The modem modeswitch extra was removed and the external usb_modeswitch
326 program should be used instead.
328 New and fixed keymaps.
338 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
339 depend on the current sysfs layout and the information not available in the
340 deprecated layout. All remaining support for the deprecated sysfs layout is
345 Fix for a possible endless loop in the new input_id program.
351 The option "ignore_device" does no longer exist. There is no way to
352 ignore an event, as libudev events can not be suppressed by rules.
353 It only prevented RUN keys from being executed, which results in an
354 inconsistent behavior in current setups.
356 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
357 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
360 The support for the deprecated IDE devices has been removed from the
361 default set of rules. Distros who still care about non-libata drivers
362 need to add the rules to the compat rules file.
364 The ID_CLASS property on input devices has been replaced by the more accurate
365 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
366 determined by the new "input_id" prober now. Some devices, such as touchpads,
367 can have several classes. So if you previously had custom udev rules which e. g.
368 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
369 ENV{ID_INPUT_KEYBOARD}=="?*".
375 To support DEVPATH strings larger than the maximum file name length, the
376 private udev database format has changed. If some software still reads the
377 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
378 Please do not port anything to the new format again, everything in /dev/.udev
379 is and always was private to udev, and may and will change any time without
382 Multiple devices claiming the same names in /dev are limited to symlinks
383 only now. Mixing identical symlink names and node names is not supported.
384 This reduces the amount of data in the database significantly.
386 NAME="%k" causes a warning now. It's is and always was completely superfluous.
387 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
390 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
391 if they are not the default. To support older kernels, the NAME= rules need to
392 be added to the compat rules file.
394 Symlinks to udevadm with the old command names are no longer resolved to
395 the udevadm commands.
397 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
400 The option "last_rule" does no longer exist. Its use breaks too many
401 things which expect to be run from independent later rules, and is an idication
402 that something needs to be fixed properly instead.
404 The gudev API is no longer marked as experimental,
405 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
406 is enabled by default now. Various projects already depend on introspection
407 information to bind dynamic languages to the gudev interfaces.
413 The udevadm trigger "--retry-failed" option, which is replaced since quite
414 a while by "--type=failed" is removed.
416 The failed tracking was not working at all for a few releases. The RUN
417 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
418 default is not to track any failing RUN executions.
420 New keymaps, new modem, hid2hci updated.
424 Fix possible crash in udevd when worker processes are busy, rules are
425 changed at the same time, and workers get killed to reload the rules.
431 Properties set with ENV{.FOO}="bar" are marked private by starting the
432 name with a '.'. They will not be stored in the database, and not be
433 exported with the event.
435 Firmware files are looked up in:
436 /lib/firmware/updates/$(uname -r)
437 /lib/firmware/updates
438 /lib/firmware/$(uname -r)
442 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
443 ata_id, instead of scsi_id, is the default tool now for ATA devices.
449 The configure options have changed because another library needs to be
450 installed in a different location. Instead of exec_prefix and udev_prefix,
451 libdir, rootlibdir and libexecdir are used. The Details are explained in
454 Event processes now get re-used after they handled an event. This reduces
455 the number of forks and the pressure on the CPU significantly, because
456 cloned event processes no longer cause page faults in the main daemon.
457 After the events have settled, a few worker processes stay around for
458 future events, all others get cleaned up.
460 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
461 Also inotify support is mandatory now to run udev.
463 The format of the queue exported by the udev damon has changed. There is
464 no longer a /dev/.udev/queue/ directory. The current event queue can be
465 accessed with udevadm settle and libudedv.
467 Libudev does not have the unstable API header anymore. From now on,
468 incompatible changes will be handled by bumping the library major version.
470 To build udev from the git tree gtk-doc is needed now. The tarballs will
471 build without it and contain the pre-built documentation. An online copy
473 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
475 The tools from the udev-extras repository have been merged into the main
476 udev repository. Some of the extras have larger external dependencies, and
477 they can be disabled with the configure switch --disable-extras.
483 The program vol_id and the library libvolume_id are removed from the
484 repository. Libvolume_id is merged with libblkid from the util-linux-ng
485 package. Persistent disk links for label and uuid depend on the
486 util-linux-ng version (2.15) of blkid now. Older versions of blkid
487 can not be used with udev.
489 Libudev allows to subscribe to udev events. To prevent unwanted messages
490 to be delivered, and waking up the subscribing process, a filter can be
491 installed, to drop messages inside a kernel socket filter. The filters
492 match on the <subsytem>:<devtype> properties of the device.
493 This is part of the ongoing effort to replace HAL, and switch current
494 users over to directly use libudev.
495 Libudev is still marked as experimental, and its interface might
496 eventually change if needed, but no major changes of the currently exported
497 interface are expected anymore, and a first stable release should happen
500 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
501 is not supported since while and udevd will log an error message at
502 startup. It should still be able to boot-up, but advanced rules and system
503 services which depend on the information not available in the old sysfs
504 format will fail to work correctly.
506 DVB device naming is supplied by the kernel now. In case older kernels
507 need to be supported, the old shell script should be added to a compat
514 The processed udev events get send back to the netlink socket. Libudev
515 provides access to these events. This is work-in-progress, to replace
516 the DeviceKit daemon functionality directly with libudev. There are
517 upcoming kernel changes to allow non-root users to subcribe to these
524 "udevadm settle" now optionally accepts a range of events to wait for,
525 instead of waiting for "all" events.
531 The installed watch for block device metadata changes is now removed
532 during event hadling, because some (broken) tools may be called from udev
533 rules and (wrongly) open the device with write access. After the finished
534 event handling the watch is restored.
540 Device nodes can be watched for changes with inotify with OPTIONS="watch".
541 If closed after being opened for writing, a "change" uevent will occur.
542 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
548 The udevadm test command has no longer a --force option, nodes and symlinks
549 are always updated with a test run now.
551 The udevd daemon can be started with --resolve-names=never to avoid all user
552 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
553 lookup user and groups every time events are handled.
559 We are currently merging the Ubuntu rules in the udev default rules,
560 and get one step closer to provide a common Linux /dev setup, regarding
561 device names, symlinks, and default device permissions. On udev startup,
562 we now expect the following groups to be resolvable to their ids with
564 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
565 LDAP setups need to make sure, that these groups are always resolvable at
566 bootup, with only the rootfs mounted, and without network access available.
568 Some systems may need to add some new, currently not used groups, or need
569 to add some users to new groups, but the cost of this change is minimal,
570 compared to the pain the current, rather random, differences between the
571 various distributions cause for upstream projects and third-party vendors.
573 In general, "normal" users who log into a machine should never be a member
574 of any such group, but the device-access should be managed by dynamic ACLs,
575 which get added and removed for the specific users on login/logout and
576 session activity/inactivity. These groups are only provided for custom setups,
577 and mainly system services, to allow proper privilege separation.
578 A video-streaming daemon uid would be a member of "audio" and "video", to get
579 access to the sound and video devices, but no "normal" user should ever belong
580 to the "audio" group, because he could listen to the built-in microphone with
581 any ssh-session established from the other side of the world.
583 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
584 which do not depend on the kernel device name. As usual, unique
585 devices - only a single one per product connected, or a real
586 USB serial number in the device - are always found with the same
587 name in the by-id/ directory.
588 Completely identical devices may overwrite their names in by-id/
589 and can only be found reliably in the by-path/ directory. Devices
590 specified by by-path/ must not change their connection, like the
591 USB port number they are plugged in, to keep their name.
593 To support some advanced features, Linux 2.6.22 is the oldest supported
594 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
595 supported. Older kernels should still work, and devices nodes should be
596 reliably created, but some rules and libudev will not work correctly because
597 the old kernels do not provide the expected information or interfaces.
603 Fix for a possible segfault while swapping network interface names in udev
610 The group "video" is part of the default rules now.
614 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
615 block devices in some cases. No common distro uses this option anymore,
616 and we do not get enough testing for this and recent udev versions. If
617 this option is not needed to run some old distro with a new kernel,
618 it should be disabled in the kernel config.
620 Bugfix for the $links substitution variable, which may crash if no links
621 are created. This should not happen in usual setups because we always
622 create /dev/{block,char}/ links.
624 The strings of the parsed rules, which are kept in memory, no longer
625 contain duplicate entries, or duplicate tails of strings. This, and the
626 new rules parsing/matching code reduces the total in-memory size of
627 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
630 The export of DEVTYPE=disk/partition got removed from the default
631 rules. This value is available from the kernel. The pnp shell script
632 modprobe hack is removed from the default rules. ACPI devices have _proper_
633 modalias support and take care of the same functionality.
634 Installations which support old kernels, but install current default
635 udev rules may want to add that to the compat rules file.
637 Libvolume_id now always probes for all known filesystems, and does not
638 stop at the first match. Some filesystems are marked as "exclusive probe",
639 and if any other filesytem type matches at the same time, libvolume_id
640 will, by default, not return any probing result. This is intended to prevent
641 mis-detection with conflicting left-over signatures found from earlier
642 file system formats. That way, we no longer depend on the probe-order
643 in case of multiple competing signatures. In some setups the kernel allows
644 to mount a volume with just the old filesystem signature still in place.
645 This may damage the new filesystem and cause data-loss, just by mounting
646 it. Because volume_id can not decide which one the correct signature is,
647 the wrong signatures need to be removed manually from the volume, or the
648 volume needs to be reformatted, to enable filesystem detection and possible
653 Fix segfault if compiled without optimization and dbg() does not get
654 compiled out and uses variables which are not available.
658 Bugfixes. (And maybe new bugs. :))
660 The rule matching engine got converted from a rule list to a token
661 array which reduced the in-memory rules representation of a full
662 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
663 Limits like 5 ENV and ATTR matches, and one single instance for most
664 other keys per rule are gone.
666 The NAME assignment is no longer special cased. If later rules assign
667 a NAME value again, the former value will be overwritten. As usual
668 for most other keys, the NAME value can be protected by doing a final
669 assignment with NAME:="<value>".
671 All udev code now uses libudev, which is also exported. The library
672 is still under development, marked as experimental, and its interface
673 may change as long as the DeviceKit integration is not finished.
675 Many thanks to Alan Jenkins for his continuous help, and finding and
676 optimizing some of the computing expensive parts.
682 Kernel devices and device nodes are connected now by reverse indizes in
683 /sys and /dev. A device number retrieved by a stat() or similar, the
684 kernel device directory can be found by looking up:
685 /sys/dev/{block,char}/<maj>:<min>
686 and the device node of the same device by looking up:
687 /dev/{block,char}/<maj>:<min>
691 Fix recently introduced bug, which caused a compilation without large
692 file support, where vol_id does not recognize raid signatures at the end
695 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
696 Seems some kernel versions prevent the creation of the ieee-* links,
697 so people used the scsi-* link which disappeared now.
699 More libudev work. Almost all udevadm functionality comes from libudev
702 udevadm trigger has a new option --type, which allows to trigger events
703 for "devices", for "subsystems", or "failed" devices. The old option
704 --retry-failed" still works, but is no longer mentioned in the man page.
710 The udevadm info --device-id-of-file= output has changed to use
711 the obvious format. Possible current users should use the --export
712 option which is not affected.
714 The old udev commands symlinks to udevadm are not installed, if
715 these symlinks are used, a warning is printed.
721 Optical drive's media is no longer probed for raid signatures,
722 reading the end of the device causes some devices to malfunction.
723 Also the offset of the last session found is used now to probe
726 The volume_id library got a major version number update to 1,
727 some deprecated functions are removed.
729 A shared library "libudev" gets installed now to provide access
730 to udev device information. DeviceKit, the successor of HAL, will
731 need this library to access the udev database and search sysfs for
733 The library is currently in an experimental state, also the API is
734 expected to change, as long as the DeviceKit integration is not
739 We use ./configure now. See INSTALL for details. Current
742 "/usr" - prefix for man pages, include files
744 "" - the root filesystem, prefix for libs and binaries
748 "lib" - directory name for libraries, not a path name
749 multilib 64bit systems may use "lib64" instead of "lib"
751 compile-in verbose debug messages
753 disable all logging and compile-out all log strings
755 link against SELInux libraries, to set the expected context
758 In the default rules, the group "disk" gets permissions 0660 instead
759 of 0640. One small step closer to unify distro rules. Some day, all
760 distros hopefully end up with the same set of rules.
762 No symlinks to udevadm are installed anymore, if they are still needed,
763 they should be provided by the package.
769 Default udev rules, which are not supposed to be edited by the user, should
770 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
771 the udev package and will be replaced with an update. Udev will pick up rule
773 /lib/udev/rules.d/ - default installed rules
774 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
775 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
776 It does not matter in which directory a rule file lives, all files are sorted
779 To help creating /dev/root, we have now:
780 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
783 In case the current --device-id-of-file is already used, please switch to
784 the --export format version, it saves the output parsing and the old
785 format will be changed to use ':' as a separator, like the format in the
790 Fix cdrom_id to properly recognize blank media.
796 Tape drive id-data is queried from /dev/bsg/* instead of the tape
797 nodes. This avoids rewinding tapes on open().
803 The symlinks udevcontrol and udevtrigger are no longer installed by
806 The scsi_id program does not depend on sysfs anymore. It can speak
807 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
808 data, which should solve some old problems with tape devices, where
809 we better do not open all tape device nodes to identify the device.
815 The cdrom_id program is replaced by an advanced version, which can
816 detect most common device types, and also properties of the inserted
817 media. This is part of moving some basic functionality from HAL into
818 udev (and the kernel).
824 The last WAIT_FOR_SYSFS rule is removed from the default rules.
826 The symlinks to udevadm for the debugging tools: udevmonitor and
827 udevtest are no longer created.
829 The symlinks to the udevadm man page for the old tool names are
832 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
833 should be prefixed with '@' to indicate that the path is not a
844 Udevstart is removed from the tree, it did not get installed for
845 a long time now, and is long replaced by trigger and settle.
851 All udev tools are merged into a single binary called udevadm.
852 The old names of the tools are built-in commands in udevadm now.
853 Symlinks to udevadm, with the names of the old tools, provide
854 the same functionality as the standalone tools. There is also
855 only a single udevadm.8 man page left for all tools.
857 Tools like mkinitramfs should be checked, if they need to include
858 udevadm in the list of files.
868 The etc/udev/rules.d/ directory now contains a default set of basic
869 udev rules. This initial version is the result of a rules file merge
870 of Fedora and openSUSE. For these both distros only a few specific
871 rules are left in their own file, named after the distro. Rules which
872 are optionally installed, because they are only valid for a specific
873 architecture, or rules for subsystems which are not always used are
874 in etc/udev/packages/.
880 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
881 actions by dynamically created rules.
883 SYMLINK=="<value>" matches agains the entries in the list of
884 currently defined symlinks. The links are not created in the
885 filesystem at that point in time, but the values can be matched.
887 RUN{ignore_error}+="<program>" will ignore any exit code from the
888 program and not record as a failed event.
894 Final merge of patches/features from the Ubuntu package.
900 Control characters in filesystem label strings are no longer silenty
901 removed, but hex-encoded, to be able to uniquely identify the device
902 by its symlink in /dev/disk/by-label/.
903 If libvolume_id is used by mount(8), LABEL= will work as expected,
904 if slashes or other characters are used in the label string.
906 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
907 can be specified now. The TEST key accepts an optional mode mask
908 TEST{0100}=="<is executable file>".
910 Scsi_id now supports a mode without expecting scsi-specific sysfs
911 entries to allow the extraction of cciss-device persistent properties.
917 In the future, we may see uuid's which are just simple character
918 strings (see the DDF Raid Specification). For that reason vol_id now
919 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
920 the creation of symlinks, the *_SAFE values ensure, that no control
921 or whitespace characters are used in the filename.
923 Possible users of libvolume_id, please use the volume_id_get_* functions.
924 The public struct will go away in a future release of the library.
930 Removal of useless extras/eventrecorder.sh.
940 The directory multiplexer for dev.d/ and hotplug.d are finally removed
941 from the udev package.
947 Symlinks can have priorities now, the priority is assigned to the device
948 and specified with OPTIONS="link_priority=100". Devices with higher
949 priorities overwrite the symlinks of devices with lower priorities.
950 If the device that currently owns the link, goes away, the symlink
951 will be removed, and recreated, pointing to the next device with the
952 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
953 more reliable, if multiple devices contain the same metadata and overwrite
956 The dasd_id program is removed from the udev tree, and dasdinfo, with the
957 needed rules, are part of the s390-tools now.
959 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
960 we may get the scsi sysfs mess fixed some day, and this will only catch
961 the devices we are looking for.
963 USB serial numbers for storage devices have the target:lun now appended,
964 to make it possibble to distinguish broken multi-lun devices with all
965 the same SCSI identifiers.
967 Note: The extra "run_directory" which searches and executes stuff in
968 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
969 with the next release. Make sure, that you don't use it anymore, or
970 provides your own implementation of that inefficient stuff.
971 We are tired of reports about a "slow udev", because these directories
972 contain stuff, that runs with _every_ event, instead of using rules,
973 that run programs only for the matching events.
983 DRIVER== will match only for devices that actually have a real
984 driver. DRIVERS== must be used, if parent devices should be
985 included in the match.
987 Libvolume_id's "linux_raid" detection needed another fix.
995 Add additional check to volume_id detection of via_raid, cause
996 some company decided to put a matching pattern all over the empty
997 storage area of their music players.
1001 Fix path_id for SAS devices.
1005 The udev daemon can be started with --debug-trace now, which will
1006 execute all events serialized to get a chance to catch a possible
1007 action that crashes the box.
1009 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1010 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1011 are excluded from the warning. Referencing parent attributes directly
1012 may break when something in the kernel driver model changes. Udev will
1013 just find the attribute by walking up the parent chain.
1015 Udevtrigger now sorts the list of devices depending on the device
1016 dependency, so a "usb" device is triggered after the parent "pci"
1021 Revert persistent-storage ata-serial '_' '-' replacement.
1027 Udevtrigger can now filter the list of devices to be triggered. Matches
1028 for subsystems or sysfs attributes can be specified.
1030 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1031 zero-sized files to avoid pointing to /sys and confuse broken tools which
1032 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1035 The rules and scripts to create udev rules for persistent network
1036 devices and optical drives are in the extras/rules_generator directory
1037 now. If you use something similar, please consider replacing your own
1038 version with this, to share the support effort. The rule_generator
1039 installs its own rules into /etc/udev/rules.d.
1041 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1042 the rule_generator depends on cdrom_id to be called in an earlier rule.
1048 Renaming of some key names (the old names still work):
1049 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1050 (The behavior of the key DRIVER will change soon in one of the next
1051 releases, to match only the event device, please switch to DRIVERS
1052 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1054 With the new key names, we have a more consistent and simpler scheme.
1055 We can match the properties of the event device only, with: KERNEL,
1056 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1057 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1058 longer mentioned in the man page and should be switched in the rule
1061 ATTR{file}="value" can be used now, to write to a sysfs file of the
1062 event device. Instead of:
1063 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1065 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1067 All the PHYSDEV* keys are deprecated and will be removed from a
1069 PHYDEVPATH - is the path of a parent device and should not be
1071 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1072 matched with SUBSYSTEMS==
1073 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1074 Newer kernels will have DRIVER in the environment,
1075 for older kernels udev puts in. Class device will
1076 no longer carry this property of a parent and
1077 DRIVERS== can be used to match such a parent value.
1078 Note that ENV{DRIVER} is only available for a few bus devices, where
1079 the driver is already bound at device event time. On coldplug, the
1080 events for a lot devices are already bound to a driver, and they will have
1081 that value set. But on hotplug, at the time the kernel creates the device,
1082 it can't know what driver may claim the device after that, therefore
1083 in most cases it will be empty.
1085 Failed events should now be re-triggered with:
1086 udevtrigger --retry-failed.
1087 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1088 files private to the udev tools. We may need to switch the current symlink
1089 target, cause some obviously broken tools try to scan all files in /dev
1090 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1091 million times. This takes ages on slow boxes.
1093 The udevinfo attribute walk (-a) now works with giving a device node
1094 name (-n) instead of a devpath (-p). The query now always works, also when
1095 no database file was created by udev.
1097 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1098 getpwnam() and getgrnam() now. One of the next releases will depend on
1099 fnmatch() and may use getopt_long().
1103 Bugfixes and small improvements.
1107 Fix path_id for recent kernels.
1113 Added support for swapping network interface names, by temporarily
1114 renaming the device and wait for the target name to become free.
1118 The built-in MODALIAS key and substitution is removed.
1122 The binary firmware helper is replaced by the usual simple
1123 shell script. Udevsend is removed from the tree.
1131 Some more keys require the correct use of '==' and '=' depending
1132 on the kind of operation beeing an assignment or a match. Rules
1133 with invalid operations are skipped and logged to syslog. Please
1134 test with udevtest if the parsing of your rules throws errors and
1135 fix possibly broken rules.
1139 Provide "udevsettle" to wait for all current udev events to finish.
1140 It also watches the current kernel netlink queue by comparing the
1141 even sequence number to make sure that there are no current pending
1142 events that have not already arrived in the daemon.
1146 Fix rule to skip persistent rules for removable IDE devices, which
1147 also skipped optical IDE drives.
1149 All *_id program are installed in /lib/udev/ by default now.
1151 No binary is stripped anymore as this should be done in the
1152 packaging process and not at build time.
1154 libvolume_id is provided as a shared library now and vol_id is
1155 linked against it. Also one of the next HAL versions will require
1156 this library, and the HAL build process will also require the
1157 header file to be installed. The copy of the same code in HAL will
1158 be removed to have only a single copy left on the system.
1162 Add persistent links for SCSI tapes. The rules file is renamed
1163 to 60-persistent-storage.rules.
1165 Create persistent path for usb devices. Can be used for all sorts
1166 of devices that can't be distinguished by other properties like
1167 multiple identical keyboards and mice connected to the same box.
1169 Provide "udevtrigger" program to request events on coldplug. The
1170 shell script is much too slow with thousends of devices.
1174 Fix persistent disk rules to exclude removable IDE drives.
1176 Warn if %e, $modalias or MODALIAS is used.
1180 Fix queue export, which wasn't correct for subsequent add/remove
1181 events for the same device.
1185 Fix cramfs detection on big endian.
1187 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1192 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1193 attributes were only checked at the parent device that matched the
1194 by BUS requested subsystem. Fix it to also look at the device we
1195 received the event for.
1197 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1202 Fix a bug where NAME="" would prevent RUN from beeing executed.
1204 RUN="/bin/program" does not longer automatically add the subsystem
1205 as the first parameter. This is from the days of /sbin/hotplug
1206 which is dead now and it's just confusing to need to add a space at
1207 the end of the program name to prevent this.
1208 If you use rules that need the subsystem as the first parameter,
1209 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1210 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1214 The udev man page has moved to udev(7) as it does not describe a command
1215 anymore. The programs udev, udevstart and udevsend are no longer installed
1216 by default and must be copied manually, if they should be installed or
1217 included in a package.
1219 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1220 the ignore rule was applied.
1222 More preparation for future sysfs changes. usb_id and scsi_id no longer
1223 depend on a magic order of devices in the /devices chain. Specific devices
1224 should be requested by their subsytem.
1226 This will always find the scsi parent device without depending on a specific
1228 dev = sysfs_device_get(devpath);
1229 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1231 The "device" link in the current sysfs layout will be automatically
1232 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1233 parent in the devpath. If a device is requested by it's symlink, like all
1234 class devices in the new sysfs layout will look like, it gets automatically
1235 resolved and substituted with the real devpath and not the symlink path.
1238 A similar logic must be applied to _all_ sysfs users, including
1239 scripts, that search along parent devices in sysfs. The explicit use of
1240 the "device" link must be avoided. With the future sysfs layout all
1241 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1242 back to the "class" or the "bus". The layout of the parent devices in
1243 /devices is not necessarily expected to be stable across kernel releases and
1244 searching for parents by their subsystem should make sysfs users tolerant
1245 for changed parent chains.
1249 Prepare udev to work with the experimental kernel patch, that moves
1250 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1252 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1253 moving the class devices to /sys/devices.
1255 Thanks again to Marco for help finding a hopefully nice compromise
1256 to make %b simpler and working again.
1260 Complete removal of libsysfs, replaced by simple helper functions
1261 which are much simpler and a bit faster. The udev daemon operatesentirely
1262 on event parameters and does not use sysfs for simple rules anymore.
1263 Please report any new bugs/problems, that may be caused by this big
1264 change. They will be fixed immediately.
1266 The enumeration format character '%e' is deprecated and will be
1267 removed sometimes from a future udev version. It never worked correctly
1268 outside of udevstart, so we can't use it with the new parallel
1269 coldplug. A simple enumeration is as useless as the devfs naming
1270 scheme, just get rid of both if you still use it.
1272 MODALIAS and $modalias is not needed and will be removed from one of
1273 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1274 the sysfs "modalias" value.
1276 Thanks a lot to Marco for all his help on finding and fixing bugs.
1280 Let scsi_id request libata drive serial numbers from page 0x80.
1282 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1283 added /dev/disk/by-name/* for device mapper device names.
1285 Removed %e from the man page. It never worked reliably outside
1286 of udevstart and udevstart is no longer recommended to use.
1290 Symlinks are now exported to the event environment. Hopefully it's no
1291 longer needed to run udevinfo from an event process, like it was
1292 mentioned on the hotplug list:
1293 UDEV [1134776873.702967] add@/block/sdb
1296 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1300 Fix a problem if udevsend is used as the hotplug handler and tries to use
1301 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1302 and this kind of problems will hopefully go away soon.
1306 All built-in logic to work around bad sysfs timing is removed with this
1307 version. The need to wait for sysfs files is almost fixed with a kernel
1308 version that doesn't work with this udev version anyway. Until we fix
1309 the timing of the "bus" link creation, the former integrated logic should
1310 be emulated by a rule placed before all other rules:
1311 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1313 The option "udev_db" does no longer exist. All udev state will be in
1314 /$udev_root/.udev/ now, there is no longer an option to set this
1316 If the init script or something else used this value, just depend on
1317 this hardcoded path. But remember _all_content_ of this directory is
1318 still private to udev and can change at any time.
1320 Default location for rule sripts and helper programs is now: /lib/udev/.
1321 Everything that is not useful on the commandline should go into this
1322 directory. Some of the helpers in the extras folder are installed there
1323 now. The rules need to be changed, to find the helpers there.
1325 Also /lib/udev/devices is recommended as a directory where packages or
1326 the user can place real device nodes, which get copied over to /dev at
1327 every boot. This should replace the various solutions with custom config
1330 Udevsend does no longer start the udev daemon. This must be done with
1331 the init script that prepares /dev on tmpfs and creates the initial nodes,
1332 before starting the daemon.
1336 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1339 The copy of klibc is removed. A systemwide installed version of klibc
1340 should be used to build a klibc udev now.
1344 NAME="" will not create any nodes, but execute RUN keys. To completely
1345 ignore an event the OPTION "ignore_device" should be used.
1347 After removal of the reorder queue, events with a TIMEOUT can be executed
1348 without any queuing now.
1352 Fixed bug in udevd, if inotify is not available. We depend on netlink
1353 uevents now, kernels without that event source will not work with that
1354 version of udev anymore.
1358 The rule parsing happens now in the daemon once at startup, all udev
1359 event processes inherit the already parsed rules from the daemon.
1360 It is shipped with SUSE10.0 and reduces heavily the system load at
1361 startup. The option to save precompiled rules and let the udev process
1362 pick the them up is removed, as it's no longer needed.
1364 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1365 device. Libsysfs is changed to "translate" the requested link into the
1366 real device path, as it would happen with the hotplug event. Otherwise
1367 device removal and the udev database will not work.
1369 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1372 A few improvements for vol_id, the filesytem probing code.
1376 Fix a stupid typo in extras/run_directory for "make install".
1378 scsi_id creates the temporary devnode now in /dev for usage with a
1379 non-writable /tmp directory.
1381 The uevent kernel socket buffer can carry app. 50.000 events now,
1382 let's see who can break this again. :)
1384 The upcoming kernel will have a new input driver core integration.
1385 Some class devices are now symlinks to the real device. libsysfs
1386 needs a fix for this to work correctly. Udevstart of older udev
1387 versions will _not_ create these devices!
1391 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1396 A bunch of mostly trivial bugfixes. From now on no node name or
1397 symlink name can contain any character than plain whitelisted ascii
1398 characters or validated utf8 byte-streams. This is needed for the
1399 /dev/disk/by-label/* links, because we import untrusted data and
1400 export it to the filesystem.
1404 More bugfixes. If udevd was started from the kernel, we don't
1405 have stdin/stdout/stderr, which broke the forked tools in some
1410 Bugfix. udevstart event ordering was broken for a long time.
1411 The new run_program() uncovered it, because /dev/null was not
1412 available while we try to run external programs.
1413 Now udevstart should create it before we run anything.
1417 Minor bugfixes and some distro rules updates. If you don't have the
1418 persistent disk rules in /dev/disk/by-*/* on your distro, just
1419 grab it from here. :)
1423 We can use socket communication now to pass events from udev to
1425 RUN+="socket:/org/freedesktop/hal/udev_event"
1426 will pass the whole udev event to the HAL daemon without the need
1427 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1431 Mostly bugfixes and see ChangeLog.
1433 The test for the existence of an environment value should be
1435 ENV{KEY}=="*" to ENV{KEY}=="?*"
1436 because "*" will not fail anymore, if the key does not exist or
1441 Bugfixes and a few tweaks described in the ChangeLog.
1445 Mostly a Bugfix release.
1447 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1448 timing with custom rules.
1452 We changed the internal rule storage format. Our large rule files took
1453 2 MB of RAM, with the change we are down to 99kB.
1455 If the device-node has been created with default name and no symlink or
1456 options are to remenber, it is not longer stored in the udevdb. HAL will
1457 need to be updated to work correctly with that change.
1459 To overrride optimization flags, OPTFLAGS may be used now.
1467 Major changes happened with this release. The goal is to take over the
1468 complete kernel-event handling and provide a more efficient way to dispatch
1469 kernel events. Replacing most of the current shell script logic and the
1470 kernel forked helper with a netlink-daemon and a rule-based event handling.
1472 o udevd listens to netlink events now. The first valid netlink event
1473 will make udevd ignore any message from udevsend that contains a
1474 SEQNUM, to avoid duplicate events. The forked events can be disabled
1476 echo "" > /proc/sys/kernel/hotplug
1477 For full support, the broken input-subsytem needs to be fixed, not to
1478 bypass the driver core.
1480 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1481 removed from udev itself and must be emulated by calling small
1482 helper binaries provided in the extras folder:
1483 make EXTRAS=extras/run_directory/
1484 will build udev_run_devd and udev_run_hotplugd, which can be called
1485 from a rule if needed:
1486 RUN+="/sbin/udev_run_hotplugd"
1487 The recommended way to handle this is to convert all the calls from
1488 the directories to explicit udev rules and get completely rid of the
1489 multiplexing. (To catch a ttyUSB event, you now no longer need to
1490 fork and exit 300 tty script instances you are not interested in, it
1491 is just one rule that matches exactly the device.)
1493 o udev handles now _all_ events not just events for class and block
1494 devices, this way it is possible to control the complete event
1495 behavior with udev rules. Especially useful for rules like:
1496 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1498 o As used in the modalias rule, udev supports now textual
1499 substitution placeholder along with the usual format chars. This
1500 needs to be documented, for now it's only visible in udev_rules_parse.c.
1502 o The rule keys support now more operations. This is documented in the
1503 man page. It is possible to add values to list-keys like the SYMLINK
1504 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1505 Also "final"-assignments are supported by using KEY:="value", which will
1506 prevent changing the key by any later rule.
1508 o kernel 2.6.12 has the "detached_state" attribute removed from
1509 sysfs, which was used to recognize sysfs population. We switched that
1510 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1511 Running this udev version on older kernels may cause a short delay for
1514 o To provide infrastructure for persistent device naming, the id programs:
1515 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1516 to export the probed data in environment key format:
1517 pim:~ # /sbin/ata_id --export /dev/hda
1518 ID_MODEL=HTS726060M9AT00
1519 ID_SERIAL=MRH401M4G6UM9B
1520 ID_REVISION=MH4OA6BA
1522 The following rules:
1523 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1524 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1527 kay@pim:~> tree /dev/disk
1530 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1531 | `-- IBM-Memory_Key -> ../../sda
1533 | |-- swap -> ../../hda1
1534 | |-- date -> ../../sda1
1535 | `-- home -> ../../hda3
1537 |-- 2E08712B0870F2E7 -> ../../hda3
1538 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1539 |-- E845-7A89 -> ../../sda1
1540 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1542 The IMPORT= operation will import these keys in the environment and make
1543 it available for later PROGRAM= and RUN= executed programs. The keys are
1544 also stored in the udevdb and can be queried from there with one of the
1547 o A few binaries are silently added to the repository, which can be used
1548 to replay kernel events from initramfs instead of using coldplug. udevd
1549 can be instructed now to queue-up events while the stored events from
1550 initramfs are filled into the udevd-queue. This code is still under
1551 development and there is no documentation now besides the code itself.
1552 The additional binaries get compiled, but are not installed by default.
1554 o There is also a temporary fix for a performance problem where too many
1555 events happen in parallel and every event needs to parse the rules.
1556 udev can now read precompiled rules stored on disk. This is likely to be
1557 replaced by a more elegant solution in a future udev version.
1561 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1562 Fix for libsysfs not to expect this file was added.
1566 All rules are applied now, but only the first matching rule with a NAME-key
1567 will be applied. All later rules with NAME-key are completely ignored. This
1568 way system supplied symlinks or permissions gets applied to user-defined
1572 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1573 to some rules, to keep the old behavior.
1575 The rules are read on "remove"-events too. That makes is possible to match
1576 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1577 instruct udev to ignore an event (OPTIONS="ignore_device").
1578 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1580 The new RUN-key supports rule-based execution of programs after device-node
1581 handling. This is meant as a general replacement for the dev.d/-directories
1582 to give fine grained control over the execution of programs.
1584 The %s{}-sysfs format char replacement values are searched at any of the
1585 devices in the device chain now, not only at the class-device.
1587 We support log priority levels now. The value udev_log in udev.conf is used
1588 to determine what is printed to syslog. This makes it possible to
1589 run a version with compiled-in debug messages in a production environment
1590 which is sometimes needed to find a bug.
1591 It is still possible to supress the inclusion of _any_ syslog usage with
1592 USE_LOG=false to create the smallest possible binaries if needed.
1593 The configured udev_log value can be overridden with the environment variable
1598 Possible use of a system-wide klibc:
1599 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1600 will link against an external klibc and our own version will be ignored.
1604 We support an unlimited count of symlinks now.
1606 If USE_STATIC=true is passed to a glibc build, we link statically and use
1607 a built-in userdb parser to resolve user and group names.
1609 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1610 we walk up the chain of physical devices to find a match.
1612 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1613 easy to skip certain attribute matches without composing rules with weird
1614 character class negations like:
1615 KERNEL="[!s][!c][!d]*"
1616 this can now be replaced with:
1618 The current simple '=' is still supported, and should work as it does today,
1619 but existing rules should be converted if possible, to be better readable.
1621 We have new ENV{}== key now, to match against a maximum of 5 environment
1624 udevstart is its own binary again, because we don't need co carry this araound
1625 with every forked event.
~ianmdlvl / elogind.git / blob