3 The udevadm tool moved from 'sbin' to 'bin'. Some tools expect
4 udevadm in 'sbin'. A symlink to udevadm in 'bin' needs to be
5 manually created if needed.
7 The systemd socket files use PassCred=yes, which requires systemd
18 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
19 and non-dracut initramfs image generators need to change the init
20 scripts. Alternatively the udev build needs to move udevd back to
21 /sbin or create a symlink in /sbin, which is not done by default.
23 The path_id, usb_id, input_id tools are built-in commands now and
24 the stand-alone tools do not exist anymore. Static lists of file in
25 initramfs generators need to be updated. For testing, the commands
26 can still be executed standalone with 'udevadm test-builtin <cmd>'.
28 The fusectl filesystem is no longer mounted directly from udev.
29 Systemd systems will take care of mounting fusectl and configfs
30 now. Non-systemd systems need to ship their own rule if they
31 need these filesystems auto-mounted.
33 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
35 The support for 'udevadm trigger --type=failed, and the
36 RUN{fail_event_on_error} attribute was removed.
38 The udev control socket is now created in /run/udev/control
39 and no longer as an abstract namespace one.
41 The rules to create persistent network interface and cdrom link
42 rules automatically in /etc/udev/rules.d/ have been disabled by
43 default. Explicit configuration will be required for these use
44 cases, udev will no longer try to write any persistent system
45 configuration from a device hotplug path.
51 The udev-acl extra is no longer enabled by default now. To enable it,
52 --enable-udev_acl needs to be given at ./configure time. On systemd
53 systems, the udev-acl rules prevent it from running as the functionality
60 Udev now enables kernel media-presence polling if available. Part
61 of udisks optical drive tray-handling moved to cdrom_id: The tray
62 is locked as soon as a media is detected to enable the receiving
63 of media-eject-request events. Media-eject-request events will
66 Libudev enumerate is now able to enumerate a subtree of a given
69 The mobile-action-modeswitch modeswitch tool was deleted. The
70 functionality is provided by usb_modeswitch now.
76 The systemd service files require systemd version 28. The systemd
77 socket activation make it possible now to start 'udevd' and 'udevadm
82 Fix bug in control message handling, which can lead to a failing
83 udevadm control --exit. Thanks to Jürg Billeter for help tracking
90 We require at least Linux kernel 2.6.32 now. Some platforms might
91 require a later kernel that supports accept4() and similar, or
92 need to backport the trivial syscall wiring to the older kernels.
94 The hid2hci tool moved to the bluez package and was removed.
96 Many of the extras can be --enable/--disabled at ./configure
97 time. The --disable-extras option was removed. Some extras have
98 been disabled by default. The current options and their defaults
99 can be checked with './configure --help'.
105 Udev logs a warning now if /run is not writable at udevd
106 startup. It will still fall back to /dev/.udev, but this is
107 now considered a bug.
109 The running udev daemon can now cleanly shut down with:
110 udevadm control --exit
112 Udev in initramfs should clean the state of the udev database
113 with: udevadm info --cleanup-db which will remove all state left
114 behind from events/rules in initramfs. If initramfs uses
115 --cleanup-db and device-mapper/LVM, the rules in initramfs need
116 to add OPTIONS+="db_persist" for all dm devices. This will
117 prevent removal of the udev database for these devices.
119 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
120 120 seconds per process. If that timeout is reached the spawned
121 process will be killed. The event timeout can be overwritten with
124 If systemd is used, udev gets now activated by netlink data.
125 Systemd will bind the netlink socket which will buffer all data.
126 If needed, such setup allows a seemless update of the udev daemon,
127 where no event can be lost during a udevd update/restart.
128 Packages need to make sure to: systemctl stop udev.socket udev.service
129 or 'mask' udev.service during the upgrade to prevent any unwanted
130 auto-spawning of udevd.
131 This version of udev conflicts with systemd version below 25. The
132 unchanged service files will not wirk correctly.
138 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
139 /run mountpoint is supposed to be a tmpfs mounted during early boot,
140 available and writable to for all tools at any time during bootup,
141 it replaces /var/run/, which should become a symlink some day.
143 If /run does not exist, or is not writable, udev will fall back using
146 On systemd systems with initramfs and LVM used, packagers must
147 make sure, that the systemd and initramfs versions match. The initramfs
148 needs to create the /run mountpoint for udev to store the data, and
149 mount this tmpfs to /run in the rootfs, so the that the udev database
150 is preserved for the udev version started in the rootfs.
152 The command 'udevadm info --convert-db' is gone. The udev daemon
153 itself, at startup, converts any old database version if necessary.
155 The systemd services files have been reorganized. The udev control
156 socket is bound by systemd and passed to the started udev daemon.
157 The udev-settle.service is no longer active by default. Services which
158 can not handle hotplug setups properly need to actively pull it in, to
159 act like a barrier. Alternatively the settle service can be unconditionally
160 'systemctl'enabled, and act like a barrier for basic.target.
162 The fstab_import callout is no longer built or installed. Udev
163 should not be used to mount, does not watch changes to fstab, and
164 should not mirror fstab values in the udev database.
170 New and updated keymaps.
176 The udev database has changed, After installation of a new udev
177 version, 'udevadm info --convert-db' should be called, to let the new
178 udev/libudev version read the already stored data.
180 udevadm now supports quoting of property values, and prefixing of
182 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
185 MY_DEVNAME='/dev/sda'
189 libudev now supports:
190 udev_device_get_is_initialized()
191 udev_enumerate_add_match_is_initialized()
192 to be able to skip devices the kernel has created , but udev has
195 libudev now supports:
196 udev_device_get_usec_since_initialized()
197 to retrieve the "age" of a udev device record.
199 GUdev supports a more generic GUdevEnumerator class, udev TAG
200 handling, device initialization and timestamp now.
202 The counterpart of /sys/dev/{char,block}/$major:$minor,
203 /dev/{char,block}/$major:$minor symlinks are now unconditionally
204 created, even when no rule files exist.
206 New and updated keymaps.
212 GUdev moved from /usr to /.
222 Persistent network naming rules are disabled inside of Qemu/KVM now.
224 New and updated keymaps.
226 Udev gets unconditionally enabled on systemd installations now. There
227 is no longer the need to to run 'systemctl enable udev.service'.
241 New and fixed keymaps.
243 Install systemd service files if applicable.
249 All distribution specific rules are removed from the udev source tree,
250 most of them are no longer needed. The Gentoo rules which allow to support
251 older kernel versions, which are not covered by the default rules anymore
252 has moved to rules/misc/30-kernel-compat.rules.
258 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
259 was removed from udevd.
261 Udevd now checks the kernel commandline for the following variables:
262 udev.log-priority=<syslog priority>
263 udev.children-max=<maximum number of workers>
264 udev.exec-delay=<seconds to delay the execution of RUN=>
265 to help debuging coldplug setups where the loading of a kernel
266 module crashes the system.
268 The subdirectory in the source tree rules/packages has been renamed to
269 rules/arch, anc contains only architecture specific rules now.
279 Now the udev daemon itself, does on startup:
280 - copy the content of /lib/udev/devices to /dev
281 - create the standard symlinks like /dev/std{in,out,err},
282 /dev/core, /dev/fd, ...
283 - use static node information provided by kernel modules
284 and creates these nodes to allow module on-demand loading
285 - possibly apply permissions to all ststic nodes from udev
286 rules which are annotated to match a static node
288 The default mode for a device node is 0600 now to match the kernel
289 created devtmpfs defaults. If GROUP= is specified and no MODE= is
290 given the default will be 0660.
296 Udev now gradually starts to pass control over the primary device nodes
297 and their names to the kernel, and will in the end only manage the
298 permissions of the node, and possibly create additional symlinks.
299 As a first step NAME="" will be ignored, and NAME= setings with names
300 other than the kernel provided name will result in a logged warning.
301 Kernels that don't provide device names, or devtmpfs is not used, will
302 still work as they did before, but it is strongly recommended to use
303 only the same names for the primary device node as the recent kernel
304 provides for all devices.
308 Fix broken firmware loader search path.
314 "udevadm trigger" defaults to "change" events now instead of "add"
315 events. The "udev boot script" might need to add "--action=add" to
316 the trigger command if not already there, in case the initial coldplug
317 events are expected as "add" events.
319 The option "all_partitons" was removed from udev. This should not be
320 needed for usual hardware. Udev can not safely make assumptions
321 about non-existing partition major/minor numbers, and therefore no
322 longer provide this unreliable and unsafe option.
324 The option "ignore_remove" was removed from udev. With devtmpfs
325 udev passed control over device nodes to the kernel. This option
326 should not be needed, or can not work as advertised. Neither
327 udev nor the kernel will remove device nodes which are copied from
328 the /lib/udev/devices/ directory.
330 All "add|change" matches are replaced by "!remove" in the rules and
331 in the udev logic. All types of events will update possible symlinks
332 and permissions, only "remove" is handled special now.
334 The modem modeswitch extra was removed and the external usb_modeswitch
335 program should be used instead.
337 New and fixed keymaps.
347 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
348 depend on the current sysfs layout and the information not available in the
349 deprecated layout. All remaining support for the deprecated sysfs layout is
354 Fix for a possible endless loop in the new input_id program.
360 The option "ignore_device" does no longer exist. There is no way to
361 ignore an event, as libudev events can not be suppressed by rules.
362 It only prevented RUN keys from being executed, which results in an
363 inconsistent behavior in current setups.
365 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
366 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
369 The support for the deprecated IDE devices has been removed from the
370 default set of rules. Distros who still care about non-libata drivers
371 need to add the rules to the compat rules file.
373 The ID_CLASS property on input devices has been replaced by the more accurate
374 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
375 determined by the new "input_id" prober now. Some devices, such as touchpads,
376 can have several classes. So if you previously had custom udev rules which e. g.
377 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
378 ENV{ID_INPUT_KEYBOARD}=="?*".
384 To support DEVPATH strings larger than the maximum file name length, the
385 private udev database format has changed. If some software still reads the
386 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
387 Please do not port anything to the new format again, everything in /dev/.udev
388 is and always was private to udev, and may and will change any time without
391 Multiple devices claiming the same names in /dev are limited to symlinks
392 only now. Mixing identical symlink names and node names is not supported.
393 This reduces the amount of data in the database significantly.
395 NAME="%k" causes a warning now. It's is and always was completely superfluous.
396 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
399 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
400 if they are not the default. To support older kernels, the NAME= rules need to
401 be added to the compat rules file.
403 Symlinks to udevadm with the old command names are no longer resolved to
404 the udevadm commands.
406 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
409 The option "last_rule" does no longer exist. Its use breaks too many
410 things which expect to be run from independent later rules, and is an idication
411 that something needs to be fixed properly instead.
413 The gudev API is no longer marked as experimental,
414 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
415 is enabled by default now. Various projects already depend on introspection
416 information to bind dynamic languages to the gudev interfaces.
422 The udevadm trigger "--retry-failed" option, which is replaced since quite
423 a while by "--type=failed" is removed.
425 The failed tracking was not working at all for a few releases. The RUN
426 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
427 default is not to track any failing RUN executions.
429 New keymaps, new modem, hid2hci updated.
433 Fix possible crash in udevd when worker processes are busy, rules are
434 changed at the same time, and workers get killed to reload the rules.
440 Properties set with ENV{.FOO}="bar" are marked private by starting the
441 name with a '.'. They will not be stored in the database, and not be
442 exported with the event.
444 Firmware files are looked up in:
445 /lib/firmware/updates/$(uname -r)
446 /lib/firmware/updates
447 /lib/firmware/$(uname -r)
451 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
452 ata_id, instead of scsi_id, is the default tool now for ATA devices.
458 The configure options have changed because another library needs to be
459 installed in a different location. Instead of exec_prefix and udev_prefix,
460 libdir, rootlibdir and libexecdir are used. The Details are explained in
463 Event processes now get re-used after they handled an event. This reduces
464 the number of forks and the pressure on the CPU significantly, because
465 cloned event processes no longer cause page faults in the main daemon.
466 After the events have settled, a few worker processes stay around for
467 future events, all others get cleaned up.
469 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
470 Also inotify support is mandatory now to run udev.
472 The format of the queue exported by the udev damon has changed. There is
473 no longer a /dev/.udev/queue/ directory. The current event queue can be
474 accessed with udevadm settle and libudedv.
476 Libudev does not have the unstable API header anymore. From now on,
477 incompatible changes will be handled by bumping the library major version.
479 To build udev from the git tree gtk-doc is needed now. The tarballs will
480 build without it and contain the pre-built documentation. An online copy
482 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
484 The tools from the udev-extras repository have been merged into the main
485 udev repository. Some of the extras have larger external dependencies, and
486 they can be disabled with the configure switch --disable-extras.
492 The program vol_id and the library libvolume_id are removed from the
493 repository. Libvolume_id is merged with libblkid from the util-linux-ng
494 package. Persistent disk links for label and uuid depend on the
495 util-linux-ng version (2.15) of blkid now. Older versions of blkid
496 can not be used with udev.
498 Libudev allows to subscribe to udev events. To prevent unwanted messages
499 to be delivered, and waking up the subscribing process, a filter can be
500 installed, to drop messages inside a kernel socket filter. The filters
501 match on the <subsytem>:<devtype> properties of the device.
502 This is part of the ongoing effort to replace HAL, and switch current
503 users over to directly use libudev.
504 Libudev is still marked as experimental, and its interface might
505 eventually change if needed, but no major changes of the currently exported
506 interface are expected anymore, and a first stable release should happen
509 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
510 is not supported since while and udevd will log an error message at
511 startup. It should still be able to boot-up, but advanced rules and system
512 services which depend on the information not available in the old sysfs
513 format will fail to work correctly.
515 DVB device naming is supplied by the kernel now. In case older kernels
516 need to be supported, the old shell script should be added to a compat
523 The processed udev events get send back to the netlink socket. Libudev
524 provides access to these events. This is work-in-progress, to replace
525 the DeviceKit daemon functionality directly with libudev. There are
526 upcoming kernel changes to allow non-root users to subcribe to these
533 "udevadm settle" now optionally accepts a range of events to wait for,
534 instead of waiting for "all" events.
540 The installed watch for block device metadata changes is now removed
541 during event hadling, because some (broken) tools may be called from udev
542 rules and (wrongly) open the device with write access. After the finished
543 event handling the watch is restored.
549 Device nodes can be watched for changes with inotify with OPTIONS="watch".
550 If closed after being opened for writing, a "change" uevent will occur.
551 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
557 The udevadm test command has no longer a --force option, nodes and symlinks
558 are always updated with a test run now.
560 The udevd daemon can be started with --resolve-names=never to avoid all user
561 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
562 lookup user and groups every time events are handled.
568 We are currently merging the Ubuntu rules in the udev default rules,
569 and get one step closer to provide a common Linux /dev setup, regarding
570 device names, symlinks, and default device permissions. On udev startup,
571 we now expect the following groups to be resolvable to their ids with
573 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
574 LDAP setups need to make sure, that these groups are always resolvable at
575 bootup, with only the rootfs mounted, and without network access available.
577 Some systems may need to add some new, currently not used groups, or need
578 to add some users to new groups, but the cost of this change is minimal,
579 compared to the pain the current, rather random, differences between the
580 various distributions cause for upstream projects and third-party vendors.
582 In general, "normal" users who log into a machine should never be a member
583 of any such group, but the device-access should be managed by dynamic ACLs,
584 which get added and removed for the specific users on login/logout and
585 session activity/inactivity. These groups are only provided for custom setups,
586 and mainly system services, to allow proper privilege separation.
587 A video-streaming daemon uid would be a member of "audio" and "video", to get
588 access to the sound and video devices, but no "normal" user should ever belong
589 to the "audio" group, because he could listen to the built-in microphone with
590 any ssh-session established from the other side of the world.
592 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
593 which do not depend on the kernel device name. As usual, unique
594 devices - only a single one per product connected, or a real
595 USB serial number in the device - are always found with the same
596 name in the by-id/ directory.
597 Completely identical devices may overwrite their names in by-id/
598 and can only be found reliably in the by-path/ directory. Devices
599 specified by by-path/ must not change their connection, like the
600 USB port number they are plugged in, to keep their name.
602 To support some advanced features, Linux 2.6.22 is the oldest supported
603 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
604 supported. Older kernels should still work, and devices nodes should be
605 reliably created, but some rules and libudev will not work correctly because
606 the old kernels do not provide the expected information or interfaces.
612 Fix for a possible segfault while swapping network interface names in udev
619 The group "video" is part of the default rules now.
623 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
624 block devices in some cases. No common distro uses this option anymore,
625 and we do not get enough testing for this and recent udev versions. If
626 this option is not needed to run some old distro with a new kernel,
627 it should be disabled in the kernel config.
629 Bugfix for the $links substitution variable, which may crash if no links
630 are created. This should not happen in usual setups because we always
631 create /dev/{block,char}/ links.
633 The strings of the parsed rules, which are kept in memory, no longer
634 contain duplicate entries, or duplicate tails of strings. This, and the
635 new rules parsing/matching code reduces the total in-memory size of
636 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
639 The export of DEVTYPE=disk/partition got removed from the default
640 rules. This value is available from the kernel. The pnp shell script
641 modprobe hack is removed from the default rules. ACPI devices have _proper_
642 modalias support and take care of the same functionality.
643 Installations which support old kernels, but install current default
644 udev rules may want to add that to the compat rules file.
646 Libvolume_id now always probes for all known filesystems, and does not
647 stop at the first match. Some filesystems are marked as "exclusive probe",
648 and if any other filesytem type matches at the same time, libvolume_id
649 will, by default, not return any probing result. This is intended to prevent
650 mis-detection with conflicting left-over signatures found from earlier
651 file system formats. That way, we no longer depend on the probe-order
652 in case of multiple competing signatures. In some setups the kernel allows
653 to mount a volume with just the old filesystem signature still in place.
654 This may damage the new filesystem and cause data-loss, just by mounting
655 it. Because volume_id can not decide which one the correct signature is,
656 the wrong signatures need to be removed manually from the volume, or the
657 volume needs to be reformatted, to enable filesystem detection and possible
662 Fix segfault if compiled without optimization and dbg() does not get
663 compiled out and uses variables which are not available.
667 Bugfixes. (And maybe new bugs. :))
669 The rule matching engine got converted from a rule list to a token
670 array which reduced the in-memory rules representation of a full
671 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
672 Limits like 5 ENV and ATTR matches, and one single instance for most
673 other keys per rule are gone.
675 The NAME assignment is no longer special cased. If later rules assign
676 a NAME value again, the former value will be overwritten. As usual
677 for most other keys, the NAME value can be protected by doing a final
678 assignment with NAME:="<value>".
680 All udev code now uses libudev, which is also exported. The library
681 is still under development, marked as experimental, and its interface
682 may change as long as the DeviceKit integration is not finished.
684 Many thanks to Alan Jenkins for his continuous help, and finding and
685 optimizing some of the computing expensive parts.
691 Kernel devices and device nodes are connected now by reverse indizes in
692 /sys and /dev. A device number retrieved by a stat() or similar, the
693 kernel device directory can be found by looking up:
694 /sys/dev/{block,char}/<maj>:<min>
695 and the device node of the same device by looking up:
696 /dev/{block,char}/<maj>:<min>
700 Fix recently introduced bug, which caused a compilation without large
701 file support, where vol_id does not recognize raid signatures at the end
704 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
705 Seems some kernel versions prevent the creation of the ieee-* links,
706 so people used the scsi-* link which disappeared now.
708 More libudev work. Almost all udevadm functionality comes from libudev
711 udevadm trigger has a new option --type, which allows to trigger events
712 for "devices", for "subsystems", or "failed" devices. The old option
713 --retry-failed" still works, but is no longer mentioned in the man page.
719 The udevadm info --device-id-of-file= output has changed to use
720 the obvious format. Possible current users should use the --export
721 option which is not affected.
723 The old udev commands symlinks to udevadm are not installed, if
724 these symlinks are used, a warning is printed.
730 Optical drive's media is no longer probed for raid signatures,
731 reading the end of the device causes some devices to malfunction.
732 Also the offset of the last session found is used now to probe
735 The volume_id library got a major version number update to 1,
736 some deprecated functions are removed.
738 A shared library "libudev" gets installed now to provide access
739 to udev device information. DeviceKit, the successor of HAL, will
740 need this library to access the udev database and search sysfs for
742 The library is currently in an experimental state, also the API is
743 expected to change, as long as the DeviceKit integration is not
748 We use ./configure now. See INSTALL for details. Current
751 "/usr" - prefix for man pages, include files
753 "" - the root filesystem, prefix for libs and binaries
757 "lib" - directory name for libraries, not a path name
758 multilib 64bit systems may use "lib64" instead of "lib"
760 compile-in verbose debug messages
762 disable all logging and compile-out all log strings
764 link against SELInux libraries, to set the expected context
767 In the default rules, the group "disk" gets permissions 0660 instead
768 of 0640. One small step closer to unify distro rules. Some day, all
769 distros hopefully end up with the same set of rules.
771 No symlinks to udevadm are installed anymore, if they are still needed,
772 they should be provided by the package.
778 Default udev rules, which are not supposed to be edited by the user, should
779 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
780 the udev package and will be replaced with an update. Udev will pick up rule
782 /lib/udev/rules.d/ - default installed rules
783 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
784 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
785 It does not matter in which directory a rule file lives, all files are sorted
788 To help creating /dev/root, we have now:
789 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
792 In case the current --device-id-of-file is already used, please switch to
793 the --export format version, it saves the output parsing and the old
794 format will be changed to use ':' as a separator, like the format in the
799 Fix cdrom_id to properly recognize blank media.
805 Tape drive id-data is queried from /dev/bsg/* instead of the tape
806 nodes. This avoids rewinding tapes on open().
812 The symlinks udevcontrol and udevtrigger are no longer installed by
815 The scsi_id program does not depend on sysfs anymore. It can speak
816 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
817 data, which should solve some old problems with tape devices, where
818 we better do not open all tape device nodes to identify the device.
824 The cdrom_id program is replaced by an advanced version, which can
825 detect most common device types, and also properties of the inserted
826 media. This is part of moving some basic functionality from HAL into
827 udev (and the kernel).
833 The last WAIT_FOR_SYSFS rule is removed from the default rules.
835 The symlinks to udevadm for the debugging tools: udevmonitor and
836 udevtest are no longer created.
838 The symlinks to the udevadm man page for the old tool names are
841 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
842 should be prefixed with '@' to indicate that the path is not a
853 Udevstart is removed from the tree, it did not get installed for
854 a long time now, and is long replaced by trigger and settle.
860 All udev tools are merged into a single binary called udevadm.
861 The old names of the tools are built-in commands in udevadm now.
862 Symlinks to udevadm, with the names of the old tools, provide
863 the same functionality as the standalone tools. There is also
864 only a single udevadm.8 man page left for all tools.
866 Tools like mkinitramfs should be checked, if they need to include
867 udevadm in the list of files.
877 The etc/udev/rules.d/ directory now contains a default set of basic
878 udev rules. This initial version is the result of a rules file merge
879 of Fedora and openSUSE. For these both distros only a few specific
880 rules are left in their own file, named after the distro. Rules which
881 are optionally installed, because they are only valid for a specific
882 architecture, or rules for subsystems which are not always used are
883 in etc/udev/packages/.
889 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
890 actions by dynamically created rules.
892 SYMLINK=="<value>" matches agains the entries in the list of
893 currently defined symlinks. The links are not created in the
894 filesystem at that point in time, but the values can be matched.
896 RUN{ignore_error}+="<program>" will ignore any exit code from the
897 program and not record as a failed event.
903 Final merge of patches/features from the Ubuntu package.
909 Control characters in filesystem label strings are no longer silenty
910 removed, but hex-encoded, to be able to uniquely identify the device
911 by its symlink in /dev/disk/by-label/.
912 If libvolume_id is used by mount(8), LABEL= will work as expected,
913 if slashes or other characters are used in the label string.
915 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
916 can be specified now. The TEST key accepts an optional mode mask
917 TEST{0100}=="<is executable file>".
919 Scsi_id now supports a mode without expecting scsi-specific sysfs
920 entries to allow the extraction of cciss-device persistent properties.
926 In the future, we may see uuid's which are just simple character
927 strings (see the DDF Raid Specification). For that reason vol_id now
928 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
929 the creation of symlinks, the *_SAFE values ensure, that no control
930 or whitespace characters are used in the filename.
932 Possible users of libvolume_id, please use the volume_id_get_* functions.
933 The public struct will go away in a future release of the library.
939 Removal of useless extras/eventrecorder.sh.
949 The directory multiplexer for dev.d/ and hotplug.d are finally removed
950 from the udev package.
956 Symlinks can have priorities now, the priority is assigned to the device
957 and specified with OPTIONS="link_priority=100". Devices with higher
958 priorities overwrite the symlinks of devices with lower priorities.
959 If the device that currently owns the link, goes away, the symlink
960 will be removed, and recreated, pointing to the next device with the
961 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
962 more reliable, if multiple devices contain the same metadata and overwrite
965 The dasd_id program is removed from the udev tree, and dasdinfo, with the
966 needed rules, are part of the s390-tools now.
968 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
969 we may get the scsi sysfs mess fixed some day, and this will only catch
970 the devices we are looking for.
972 USB serial numbers for storage devices have the target:lun now appended,
973 to make it possibble to distinguish broken multi-lun devices with all
974 the same SCSI identifiers.
976 Note: The extra "run_directory" which searches and executes stuff in
977 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
978 with the next release. Make sure, that you don't use it anymore, or
979 provides your own implementation of that inefficient stuff.
980 We are tired of reports about a "slow udev", because these directories
981 contain stuff, that runs with _every_ event, instead of using rules,
982 that run programs only for the matching events.
992 DRIVER== will match only for devices that actually have a real
993 driver. DRIVERS== must be used, if parent devices should be
994 included in the match.
996 Libvolume_id's "linux_raid" detection needed another fix.
1004 Add additional check to volume_id detection of via_raid, cause
1005 some company decided to put a matching pattern all over the empty
1006 storage area of their music players.
1010 Fix path_id for SAS devices.
1014 The udev daemon can be started with --debug-trace now, which will
1015 execute all events serialized to get a chance to catch a possible
1016 action that crashes the box.
1018 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1019 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1020 are excluded from the warning. Referencing parent attributes directly
1021 may break when something in the kernel driver model changes. Udev will
1022 just find the attribute by walking up the parent chain.
1024 Udevtrigger now sorts the list of devices depending on the device
1025 dependency, so a "usb" device is triggered after the parent "pci"
1030 Revert persistent-storage ata-serial '_' '-' replacement.
1036 Udevtrigger can now filter the list of devices to be triggered. Matches
1037 for subsystems or sysfs attributes can be specified.
1039 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1040 zero-sized files to avoid pointing to /sys and confuse broken tools which
1041 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1044 The rules and scripts to create udev rules for persistent network
1045 devices and optical drives are in the extras/rules_generator directory
1046 now. If you use something similar, please consider replacing your own
1047 version with this, to share the support effort. The rule_generator
1048 installs its own rules into /etc/udev/rules.d.
1050 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1051 the rule_generator depends on cdrom_id to be called in an earlier rule.
1057 Renaming of some key names (the old names still work):
1058 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1059 (The behavior of the key DRIVER will change soon in one of the next
1060 releases, to match only the event device, please switch to DRIVERS
1061 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1063 With the new key names, we have a more consistent and simpler scheme.
1064 We can match the properties of the event device only, with: KERNEL,
1065 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1066 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1067 longer mentioned in the man page and should be switched in the rule
1070 ATTR{file}="value" can be used now, to write to a sysfs file of the
1071 event device. Instead of:
1072 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1074 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1076 All the PHYSDEV* keys are deprecated and will be removed from a
1078 PHYDEVPATH - is the path of a parent device and should not be
1080 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1081 matched with SUBSYSTEMS==
1082 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1083 Newer kernels will have DRIVER in the environment,
1084 for older kernels udev puts in. Class device will
1085 no longer carry this property of a parent and
1086 DRIVERS== can be used to match such a parent value.
1087 Note that ENV{DRIVER} is only available for a few bus devices, where
1088 the driver is already bound at device event time. On coldplug, the
1089 events for a lot devices are already bound to a driver, and they will have
1090 that value set. But on hotplug, at the time the kernel creates the device,
1091 it can't know what driver may claim the device after that, therefore
1092 in most cases it will be empty.
1094 Failed events should now be re-triggered with:
1095 udevtrigger --retry-failed.
1096 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1097 files private to the udev tools. We may need to switch the current symlink
1098 target, cause some obviously broken tools try to scan all files in /dev
1099 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1100 million times. This takes ages on slow boxes.
1102 The udevinfo attribute walk (-a) now works with giving a device node
1103 name (-n) instead of a devpath (-p). The query now always works, also when
1104 no database file was created by udev.
1106 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1107 getpwnam() and getgrnam() now. One of the next releases will depend on
1108 fnmatch() and may use getopt_long().
1112 Bugfixes and small improvements.
1116 Fix path_id for recent kernels.
1122 Added support for swapping network interface names, by temporarily
1123 renaming the device and wait for the target name to become free.
1127 The built-in MODALIAS key and substitution is removed.
1131 The binary firmware helper is replaced by the usual simple
1132 shell script. Udevsend is removed from the tree.
1140 Some more keys require the correct use of '==' and '=' depending
1141 on the kind of operation beeing an assignment or a match. Rules
1142 with invalid operations are skipped and logged to syslog. Please
1143 test with udevtest if the parsing of your rules throws errors and
1144 fix possibly broken rules.
1148 Provide "udevsettle" to wait for all current udev events to finish.
1149 It also watches the current kernel netlink queue by comparing the
1150 even sequence number to make sure that there are no current pending
1151 events that have not already arrived in the daemon.
1155 Fix rule to skip persistent rules for removable IDE devices, which
1156 also skipped optical IDE drives.
1158 All *_id program are installed in /lib/udev/ by default now.
1160 No binary is stripped anymore as this should be done in the
1161 packaging process and not at build time.
1163 libvolume_id is provided as a shared library now and vol_id is
1164 linked against it. Also one of the next HAL versions will require
1165 this library, and the HAL build process will also require the
1166 header file to be installed. The copy of the same code in HAL will
1167 be removed to have only a single copy left on the system.
1171 Add persistent links for SCSI tapes. The rules file is renamed
1172 to 60-persistent-storage.rules.
1174 Create persistent path for usb devices. Can be used for all sorts
1175 of devices that can't be distinguished by other properties like
1176 multiple identical keyboards and mice connected to the same box.
1178 Provide "udevtrigger" program to request events on coldplug. The
1179 shell script is much too slow with thousends of devices.
1183 Fix persistent disk rules to exclude removable IDE drives.
1185 Warn if %e, $modalias or MODALIAS is used.
1189 Fix queue export, which wasn't correct for subsequent add/remove
1190 events for the same device.
1194 Fix cramfs detection on big endian.
1196 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1201 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1202 attributes were only checked at the parent device that matched the
1203 by BUS requested subsystem. Fix it to also look at the device we
1204 received the event for.
1206 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1211 Fix a bug where NAME="" would prevent RUN from beeing executed.
1213 RUN="/bin/program" does not longer automatically add the subsystem
1214 as the first parameter. This is from the days of /sbin/hotplug
1215 which is dead now and it's just confusing to need to add a space at
1216 the end of the program name to prevent this.
1217 If you use rules that need the subsystem as the first parameter,
1218 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1219 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1223 The udev man page has moved to udev(7) as it does not describe a command
1224 anymore. The programs udev, udevstart and udevsend are no longer installed
1225 by default and must be copied manually, if they should be installed or
1226 included in a package.
1228 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1229 the ignore rule was applied.
1231 More preparation for future sysfs changes. usb_id and scsi_id no longer
1232 depend on a magic order of devices in the /devices chain. Specific devices
1233 should be requested by their subsytem.
1235 This will always find the scsi parent device without depending on a specific
1237 dev = sysfs_device_get(devpath);
1238 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1240 The "device" link in the current sysfs layout will be automatically
1241 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1242 parent in the devpath. If a device is requested by it's symlink, like all
1243 class devices in the new sysfs layout will look like, it gets automatically
1244 resolved and substituted with the real devpath and not the symlink path.
1247 A similar logic must be applied to _all_ sysfs users, including
1248 scripts, that search along parent devices in sysfs. The explicit use of
1249 the "device" link must be avoided. With the future sysfs layout all
1250 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1251 back to the "class" or the "bus". The layout of the parent devices in
1252 /devices is not necessarily expected to be stable across kernel releases and
1253 searching for parents by their subsystem should make sysfs users tolerant
1254 for changed parent chains.
1258 Prepare udev to work with the experimental kernel patch, that moves
1259 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1261 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1262 moving the class devices to /sys/devices.
1264 Thanks again to Marco for help finding a hopefully nice compromise
1265 to make %b simpler and working again.
1269 Complete removal of libsysfs, replaced by simple helper functions
1270 which are much simpler and a bit faster. The udev daemon operatesentirely
1271 on event parameters and does not use sysfs for simple rules anymore.
1272 Please report any new bugs/problems, that may be caused by this big
1273 change. They will be fixed immediately.
1275 The enumeration format character '%e' is deprecated and will be
1276 removed sometimes from a future udev version. It never worked correctly
1277 outside of udevstart, so we can't use it with the new parallel
1278 coldplug. A simple enumeration is as useless as the devfs naming
1279 scheme, just get rid of both if you still use it.
1281 MODALIAS and $modalias is not needed and will be removed from one of
1282 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1283 the sysfs "modalias" value.
1285 Thanks a lot to Marco for all his help on finding and fixing bugs.
1289 Let scsi_id request libata drive serial numbers from page 0x80.
1291 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1292 added /dev/disk/by-name/* for device mapper device names.
1294 Removed %e from the man page. It never worked reliably outside
1295 of udevstart and udevstart is no longer recommended to use.
1299 Symlinks are now exported to the event environment. Hopefully it's no
1300 longer needed to run udevinfo from an event process, like it was
1301 mentioned on the hotplug list:
1302 UDEV [1134776873.702967] add@/block/sdb
1305 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1309 Fix a problem if udevsend is used as the hotplug handler and tries to use
1310 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1311 and this kind of problems will hopefully go away soon.
1315 All built-in logic to work around bad sysfs timing is removed with this
1316 version. The need to wait for sysfs files is almost fixed with a kernel
1317 version that doesn't work with this udev version anyway. Until we fix
1318 the timing of the "bus" link creation, the former integrated logic should
1319 be emulated by a rule placed before all other rules:
1320 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1322 The option "udev_db" does no longer exist. All udev state will be in
1323 /$udev_root/.udev/ now, there is no longer an option to set this
1325 If the init script or something else used this value, just depend on
1326 this hardcoded path. But remember _all_content_ of this directory is
1327 still private to udev and can change at any time.
1329 Default location for rule sripts and helper programs is now: /lib/udev/.
1330 Everything that is not useful on the commandline should go into this
1331 directory. Some of the helpers in the extras folder are installed there
1332 now. The rules need to be changed, to find the helpers there.
1334 Also /lib/udev/devices is recommended as a directory where packages or
1335 the user can place real device nodes, which get copied over to /dev at
1336 every boot. This should replace the various solutions with custom config
1339 Udevsend does no longer start the udev daemon. This must be done with
1340 the init script that prepares /dev on tmpfs and creates the initial nodes,
1341 before starting the daemon.
1345 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1348 The copy of klibc is removed. A systemwide installed version of klibc
1349 should be used to build a klibc udev now.
1353 NAME="" will not create any nodes, but execute RUN keys. To completely
1354 ignore an event the OPTION "ignore_device" should be used.
1356 After removal of the reorder queue, events with a TIMEOUT can be executed
1357 without any queuing now.
1361 Fixed bug in udevd, if inotify is not available. We depend on netlink
1362 uevents now, kernels without that event source will not work with that
1363 version of udev anymore.
1367 The rule parsing happens now in the daemon once at startup, all udev
1368 event processes inherit the already parsed rules from the daemon.
1369 It is shipped with SUSE10.0 and reduces heavily the system load at
1370 startup. The option to save precompiled rules and let the udev process
1371 pick the them up is removed, as it's no longer needed.
1373 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1374 device. Libsysfs is changed to "translate" the requested link into the
1375 real device path, as it would happen with the hotplug event. Otherwise
1376 device removal and the udev database will not work.
1378 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1381 A few improvements for vol_id, the filesytem probing code.
1385 Fix a stupid typo in extras/run_directory for "make install".
1387 scsi_id creates the temporary devnode now in /dev for usage with a
1388 non-writable /tmp directory.
1390 The uevent kernel socket buffer can carry app. 50.000 events now,
1391 let's see who can break this again. :)
1393 The upcoming kernel will have a new input driver core integration.
1394 Some class devices are now symlinks to the real device. libsysfs
1395 needs a fix for this to work correctly. Udevstart of older udev
1396 versions will _not_ create these devices!
1400 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1405 A bunch of mostly trivial bugfixes. From now on no node name or
1406 symlink name can contain any character than plain whitelisted ascii
1407 characters or validated utf8 byte-streams. This is needed for the
1408 /dev/disk/by-label/* links, because we import untrusted data and
1409 export it to the filesystem.
1413 More bugfixes. If udevd was started from the kernel, we don't
1414 have stdin/stdout/stderr, which broke the forked tools in some
1419 Bugfix. udevstart event ordering was broken for a long time.
1420 The new run_program() uncovered it, because /dev/null was not
1421 available while we try to run external programs.
1422 Now udevstart should create it before we run anything.
1426 Minor bugfixes and some distro rules updates. If you don't have the
1427 persistent disk rules in /dev/disk/by-*/* on your distro, just
1428 grab it from here. :)
1432 We can use socket communication now to pass events from udev to
1434 RUN+="socket:/org/freedesktop/hal/udev_event"
1435 will pass the whole udev event to the HAL daemon without the need
1436 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1440 Mostly bugfixes and see ChangeLog.
1442 The test for the existence of an environment value should be
1444 ENV{KEY}=="*" to ENV{KEY}=="?*"
1445 because "*" will not fail anymore, if the key does not exist or
1450 Bugfixes and a few tweaks described in the ChangeLog.
1454 Mostly a Bugfix release.
1456 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1457 timing with custom rules.
1461 We changed the internal rule storage format. Our large rule files took
1462 2 MB of RAM, with the change we are down to 99kB.
1464 If the device-node has been created with default name and no symlink or
1465 options are to remenber, it is not longer stored in the udevdb. HAL will
1466 need to be updated to work correctly with that change.
1468 To overrride optimization flags, OPTFLAGS may be used now.
1476 Major changes happened with this release. The goal is to take over the
1477 complete kernel-event handling and provide a more efficient way to dispatch
1478 kernel events. Replacing most of the current shell script logic and the
1479 kernel forked helper with a netlink-daemon and a rule-based event handling.
1481 o udevd listens to netlink events now. The first valid netlink event
1482 will make udevd ignore any message from udevsend that contains a
1483 SEQNUM, to avoid duplicate events. The forked events can be disabled
1485 echo "" > /proc/sys/kernel/hotplug
1486 For full support, the broken input-subsytem needs to be fixed, not to
1487 bypass the driver core.
1489 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1490 removed from udev itself and must be emulated by calling small
1491 helper binaries provided in the extras folder:
1492 make EXTRAS=extras/run_directory/
1493 will build udev_run_devd and udev_run_hotplugd, which can be called
1494 from a rule if needed:
1495 RUN+="/sbin/udev_run_hotplugd"
1496 The recommended way to handle this is to convert all the calls from
1497 the directories to explicit udev rules and get completely rid of the
1498 multiplexing. (To catch a ttyUSB event, you now no longer need to
1499 fork and exit 300 tty script instances you are not interested in, it
1500 is just one rule that matches exactly the device.)
1502 o udev handles now _all_ events not just events for class and block
1503 devices, this way it is possible to control the complete event
1504 behavior with udev rules. Especially useful for rules like:
1505 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1507 o As used in the modalias rule, udev supports now textual
1508 substitution placeholder along with the usual format chars. This
1509 needs to be documented, for now it's only visible in udev_rules_parse.c.
1511 o The rule keys support now more operations. This is documented in the
1512 man page. It is possible to add values to list-keys like the SYMLINK
1513 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1514 Also "final"-assignments are supported by using KEY:="value", which will
1515 prevent changing the key by any later rule.
1517 o kernel 2.6.12 has the "detached_state" attribute removed from
1518 sysfs, which was used to recognize sysfs population. We switched that
1519 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1520 Running this udev version on older kernels may cause a short delay for
1523 o To provide infrastructure for persistent device naming, the id programs:
1524 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1525 to export the probed data in environment key format:
1526 pim:~ # /sbin/ata_id --export /dev/hda
1527 ID_MODEL=HTS726060M9AT00
1528 ID_SERIAL=MRH401M4G6UM9B
1529 ID_REVISION=MH4OA6BA
1531 The following rules:
1532 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1533 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1536 kay@pim:~> tree /dev/disk
1539 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1540 | `-- IBM-Memory_Key -> ../../sda
1542 | |-- swap -> ../../hda1
1543 | |-- date -> ../../sda1
1544 | `-- home -> ../../hda3
1546 |-- 2E08712B0870F2E7 -> ../../hda3
1547 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1548 |-- E845-7A89 -> ../../sda1
1549 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1551 The IMPORT= operation will import these keys in the environment and make
1552 it available for later PROGRAM= and RUN= executed programs. The keys are
1553 also stored in the udevdb and can be queried from there with one of the
1556 o A few binaries are silently added to the repository, which can be used
1557 to replay kernel events from initramfs instead of using coldplug. udevd
1558 can be instructed now to queue-up events while the stored events from
1559 initramfs are filled into the udevd-queue. This code is still under
1560 development and there is no documentation now besides the code itself.
1561 The additional binaries get compiled, but are not installed by default.
1563 o There is also a temporary fix for a performance problem where too many
1564 events happen in parallel and every event needs to parse the rules.
1565 udev can now read precompiled rules stored on disk. This is likely to be
1566 replaced by a more elegant solution in a future udev version.
1570 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1571 Fix for libsysfs not to expect this file was added.
1575 All rules are applied now, but only the first matching rule with a NAME-key
1576 will be applied. All later rules with NAME-key are completely ignored. This
1577 way system supplied symlinks or permissions gets applied to user-defined
1581 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1582 to some rules, to keep the old behavior.
1584 The rules are read on "remove"-events too. That makes is possible to match
1585 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1586 instruct udev to ignore an event (OPTIONS="ignore_device").
1587 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1589 The new RUN-key supports rule-based execution of programs after device-node
1590 handling. This is meant as a general replacement for the dev.d/-directories
1591 to give fine grained control over the execution of programs.
1593 The %s{}-sysfs format char replacement values are searched at any of the
1594 devices in the device chain now, not only at the class-device.
1596 We support log priority levels now. The value udev_log in udev.conf is used
1597 to determine what is printed to syslog. This makes it possible to
1598 run a version with compiled-in debug messages in a production environment
1599 which is sometimes needed to find a bug.
1600 It is still possible to supress the inclusion of _any_ syslog usage with
1601 USE_LOG=false to create the smallest possible binaries if needed.
1602 The configured udev_log value can be overridden with the environment variable
1607 Possible use of a system-wide klibc:
1608 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1609 will link against an external klibc and our own version will be ignored.
1613 We support an unlimited count of symlinks now.
1615 If USE_STATIC=true is passed to a glibc build, we link statically and use
1616 a built-in userdb parser to resolve user and group names.
1618 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1619 we walk up the chain of physical devices to find a match.
1621 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1622 easy to skip certain attribute matches without composing rules with weird
1623 character class negations like:
1624 KERNEL="[!s][!c][!d]*"
1625 this can now be replaced with:
1627 The current simple '=' is still supported, and should work as it does today,
1628 but existing rules should be converted if possible, to be better readable.
1630 We have new ENV{}== key now, to match against a maximum of 5 environment
1633 udevstart is its own binary again, because we don't need co carry this araound
1634 with every forked event.
~ianmdlvl / elogind.git / blob