3 Bugfix for rule_generator instalation.
7 The 'devtmpfs' filesystem is required now, udev will not create or delete
8 device nodes anymore, it only adjusts permissions and ownership of device
9 nodes and maintains additional symlinks.
11 A writable /run directory (ususally tmpfs) is required now for a fully
12 functional udev, there is no longer a fallback to /dev/.udev.
14 The default 'configure' install locations have changed. Packages for systems
15 with the historic / vs. /usr split need to be adapted, otherwise udev will
16 be installed in /usr and not work properly. Example configuration options
17 to install things the traditional way are in INSTALL.
19 The default install location of the 'udevadm' tool moved from 'sbin'
20 to /usr/bin. Some tools expect udevadm in 'sbin', a symlink to udevadm
21 needs to be manually created if needed, or --bindir=/sbin be specified.
23 The expected value of '--libexecdir=' has changed and must no longer contain
26 Kernel modules are now loaded directly by linking udev to 'libkmod'. The
27 'modprobe' tool is no longer executed by udev.
29 The 'blkid' tool is no longer executed from udev rules. Udev links
30 directly to libblkid now.
32 Firmware is loaded natively by udev now, the external 'firmware' binary
35 All built-in tools can be listed and tested with 'udevadm test-builtin'.
37 The 'udevadm control --reload-rules' option has been renamed to '--reload'.
38 It now also reloads the kernel module configuration.
40 The systemd socket files use PassCredentials=yes, which is available in
43 The udev build system only creates a .xz tarball now.
45 All tabs in the source code used for indentation are replaced by spaces now. :)
55 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
56 and non-dracut initramfs image generators need to change the init
57 scripts. Alternatively the udev build needs to move udevd back to
58 /sbin or create a symlink in /sbin, which is not done by default.
60 The path_id, usb_id, input_id tools are built-in commands now and
61 the stand-alone tools do not exist anymore. Static lists of file in
62 initramfs generators need to be updated. For testing, the commands
63 can still be executed standalone with 'udevadm test-builtin <cmd>'.
65 The fusectl filesystem is no longer mounted directly from udev.
66 Systemd systems will take care of mounting fusectl and configfs
67 now. Non-systemd systems need to ship their own rule if they
68 need these filesystems auto-mounted.
70 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
72 The support for 'udevadm trigger --type=failed, and the
73 RUN{fail_event_on_error} attribute was removed.
75 The udev control socket is now created in /run/udev/control
76 and no longer as an abstract namespace one.
78 The rules to create persistent network interface and cdrom link
79 rules automatically in /etc/udev/rules.d/ have been disabled by
80 default. Explicit configuration will be required for these use
81 cases, udev will no longer try to write any persistent system
82 configuration from a device hotplug path.
88 The udev-acl extra is no longer enabled by default now. To enable it,
89 --enable-udev_acl needs to be given at ./configure time. On systemd
90 systems, the udev-acl rules prevent it from running as the functionality
97 Udev now enables kernel media-presence polling if available. Part
98 of udisks optical drive tray-handling moved to cdrom_id: The tray
99 is locked as soon as a media is detected to enable the receiving
100 of media-eject-request events. Media-eject-request events will
103 Libudev enumerate is now able to enumerate a subtree of a given
106 The mobile-action-modeswitch modeswitch tool was deleted. The
107 functionality is provided by usb_modeswitch now.
113 The systemd service files require systemd version 28. The systemd
114 socket activation make it possible now to start 'udevd' and 'udevadm
115 trigger' in parallel.
119 Fix bug in control message handling, which can lead to a failing
120 udevadm control --exit. Thanks to Jürg Billeter for help tracking
127 We require at least Linux kernel 2.6.32 now. Some platforms might
128 require a later kernel that supports accept4() and similar, or
129 need to backport the trivial syscall wiring to the older kernels.
131 The hid2hci tool moved to the bluez package and was removed.
133 Many of the extras can be --enable/--disabled at ./configure
134 time. The --disable-extras option was removed. Some extras have
135 been disabled by default. The current options and their defaults
136 can be checked with './configure --help'.
142 Udev logs a warning now if /run is not writable at udevd
143 startup. It will still fall back to /dev/.udev, but this is
144 now considered a bug.
146 The running udev daemon can now cleanly shut down with:
147 udevadm control --exit
149 Udev in initramfs should clean the state of the udev database
150 with: udevadm info --cleanup-db which will remove all state left
151 behind from events/rules in initramfs. If initramfs uses
152 --cleanup-db and device-mapper/LVM, the rules in initramfs need
153 to add OPTIONS+="db_persist" for all dm devices. This will
154 prevent removal of the udev database for these devices.
156 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
157 120 seconds per process. If that timeout is reached the spawned
158 process will be killed. The event timeout can be overwritten with
161 If systemd is used, udev gets now activated by netlink data.
162 Systemd will bind the netlink socket which will buffer all data.
163 If needed, such setup allows a seemless update of the udev daemon,
164 where no event can be lost during a udevd update/restart.
165 Packages need to make sure to: systemctl stop udev.socket udev.service
166 or 'mask' udev.service during the upgrade to prevent any unwanted
167 auto-spawning of udevd.
168 This version of udev conflicts with systemd version below 25. The
169 unchanged service files will not wirk correctly.
175 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
176 /run mountpoint is supposed to be a tmpfs mounted during early boot,
177 available and writable to for all tools at any time during bootup,
178 it replaces /var/run/, which should become a symlink some day.
180 If /run does not exist, or is not writable, udev will fall back using
183 On systemd systems with initramfs and LVM used, packagers must
184 make sure, that the systemd and initramfs versions match. The initramfs
185 needs to create the /run mountpoint for udev to store the data, and
186 mount this tmpfs to /run in the rootfs, so the that the udev database
187 is preserved for the udev version started in the rootfs.
189 The command 'udevadm info --convert-db' is gone. The udev daemon
190 itself, at startup, converts any old database version if necessary.
192 The systemd services files have been reorganized. The udev control
193 socket is bound by systemd and passed to the started udev daemon.
194 The udev-settle.service is no longer active by default. Services which
195 can not handle hotplug setups properly need to actively pull it in, to
196 act like a barrier. Alternatively the settle service can be unconditionally
197 'systemctl'enabled, and act like a barrier for basic.target.
199 The fstab_import callout is no longer built or installed. Udev
200 should not be used to mount, does not watch changes to fstab, and
201 should not mirror fstab values in the udev database.
207 New and updated keymaps.
213 The udev database has changed, After installation of a new udev
214 version, 'udevadm info --convert-db' should be called, to let the new
215 udev/libudev version read the already stored data.
217 udevadm now supports quoting of property values, and prefixing of
219 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
222 MY_DEVNAME='/dev/sda'
226 libudev now supports:
227 udev_device_get_is_initialized()
228 udev_enumerate_add_match_is_initialized()
229 to be able to skip devices the kernel has created , but udev has
232 libudev now supports:
233 udev_device_get_usec_since_initialized()
234 to retrieve the "age" of a udev device record.
236 GUdev supports a more generic GUdevEnumerator class, udev TAG
237 handling, device initialization and timestamp now.
239 The counterpart of /sys/dev/{char,block}/$major:$minor,
240 /dev/{char,block}/$major:$minor symlinks are now unconditionally
241 created, even when no rule files exist.
243 New and updated keymaps.
249 GUdev moved from /usr to /.
259 Persistent network naming rules are disabled inside of Qemu/KVM now.
261 New and updated keymaps.
263 Udev gets unconditionally enabled on systemd installations now. There
264 is no longer the need to to run 'systemctl enable udev.service'.
278 New and fixed keymaps.
280 Install systemd service files if applicable.
286 All distribution specific rules are removed from the udev source tree,
287 most of them are no longer needed. The Gentoo rules which allow to support
288 older kernel versions, which are not covered by the default rules anymore
289 has moved to rules/misc/30-kernel-compat.rules.
295 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
296 was removed from udevd.
298 Udevd now checks the kernel commandline for the following variables:
299 udev.log-priority=<syslog priority>
300 udev.children-max=<maximum number of workers>
301 udev.exec-delay=<seconds to delay the execution of RUN=>
302 to help debuging coldplug setups where the loading of a kernel
303 module crashes the system.
305 The subdirectory in the source tree rules/packages has been renamed to
306 rules/arch, anc contains only architecture specific rules now.
316 Now the udev daemon itself, does on startup:
317 - copy the content of /lib/udev/devices to /dev
318 - create the standard symlinks like /dev/std{in,out,err},
319 /dev/core, /dev/fd, ...
320 - use static node information provided by kernel modules
321 and creates these nodes to allow module on-demand loading
322 - possibly apply permissions to all ststic nodes from udev
323 rules which are annotated to match a static node
325 The default mode for a device node is 0600 now to match the kernel
326 created devtmpfs defaults. If GROUP= is specified and no MODE= is
327 given the default will be 0660.
333 Udev now gradually starts to pass control over the primary device nodes
334 and their names to the kernel, and will in the end only manage the
335 permissions of the node, and possibly create additional symlinks.
336 As a first step NAME="" will be ignored, and NAME= setings with names
337 other than the kernel provided name will result in a logged warning.
338 Kernels that don't provide device names, or devtmpfs is not used, will
339 still work as they did before, but it is strongly recommended to use
340 only the same names for the primary device node as the recent kernel
341 provides for all devices.
345 Fix broken firmware loader search path.
351 "udevadm trigger" defaults to "change" events now instead of "add"
352 events. The "udev boot script" might need to add "--action=add" to
353 the trigger command if not already there, in case the initial coldplug
354 events are expected as "add" events.
356 The option "all_partitons" was removed from udev. This should not be
357 needed for usual hardware. Udev can not safely make assumptions
358 about non-existing partition major/minor numbers, and therefore no
359 longer provide this unreliable and unsafe option.
361 The option "ignore_remove" was removed from udev. With devtmpfs
362 udev passed control over device nodes to the kernel. This option
363 should not be needed, or can not work as advertised. Neither
364 udev nor the kernel will remove device nodes which are copied from
365 the /lib/udev/devices/ directory.
367 All "add|change" matches are replaced by "!remove" in the rules and
368 in the udev logic. All types of events will update possible symlinks
369 and permissions, only "remove" is handled special now.
371 The modem modeswitch extra was removed and the external usb_modeswitch
372 program should be used instead.
374 New and fixed keymaps.
384 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
385 depend on the current sysfs layout and the information not available in the
386 deprecated layout. All remaining support for the deprecated sysfs layout is
391 Fix for a possible endless loop in the new input_id program.
397 The option "ignore_device" does no longer exist. There is no way to
398 ignore an event, as libudev events can not be suppressed by rules.
399 It only prevented RUN keys from being executed, which results in an
400 inconsistent behavior in current setups.
402 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
403 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
406 The support for the deprecated IDE devices has been removed from the
407 default set of rules. Distros who still care about non-libata drivers
408 need to add the rules to the compat rules file.
410 The ID_CLASS property on input devices has been replaced by the more accurate
411 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
412 determined by the new "input_id" prober now. Some devices, such as touchpads,
413 can have several classes. So if you previously had custom udev rules which e. g.
414 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
415 ENV{ID_INPUT_KEYBOARD}=="?*".
421 To support DEVPATH strings larger than the maximum file name length, the
422 private udev database format has changed. If some software still reads the
423 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
424 Please do not port anything to the new format again, everything in /dev/.udev
425 is and always was private to udev, and may and will change any time without
428 Multiple devices claiming the same names in /dev are limited to symlinks
429 only now. Mixing identical symlink names and node names is not supported.
430 This reduces the amount of data in the database significantly.
432 NAME="%k" causes a warning now. It's is and always was completely superfluous.
433 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
436 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
437 if they are not the default. To support older kernels, the NAME= rules need to
438 be added to the compat rules file.
440 Symlinks to udevadm with the old command names are no longer resolved to
441 the udevadm commands.
443 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
446 The option "last_rule" does no longer exist. Its use breaks too many
447 things which expect to be run from independent later rules, and is an idication
448 that something needs to be fixed properly instead.
450 The gudev API is no longer marked as experimental,
451 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
452 is enabled by default now. Various projects already depend on introspection
453 information to bind dynamic languages to the gudev interfaces.
459 The udevadm trigger "--retry-failed" option, which is replaced since quite
460 a while by "--type=failed" is removed.
462 The failed tracking was not working at all for a few releases. The RUN
463 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
464 default is not to track any failing RUN executions.
466 New keymaps, new modem, hid2hci updated.
470 Fix possible crash in udevd when worker processes are busy, rules are
471 changed at the same time, and workers get killed to reload the rules.
477 Properties set with ENV{.FOO}="bar" are marked private by starting the
478 name with a '.'. They will not be stored in the database, and not be
479 exported with the event.
481 Firmware files are looked up in:
482 /lib/firmware/updates/$(uname -r)
483 /lib/firmware/updates
484 /lib/firmware/$(uname -r)
488 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
489 ata_id, instead of scsi_id, is the default tool now for ATA devices.
495 The configure options have changed because another library needs to be
496 installed in a different location. Instead of exec_prefix and udev_prefix,
497 libdir, rootlibdir and libexecdir are used. The Details are explained in
500 Event processes now get re-used after they handled an event. This reduces
501 the number of forks and the pressure on the CPU significantly, because
502 cloned event processes no longer cause page faults in the main daemon.
503 After the events have settled, a few worker processes stay around for
504 future events, all others get cleaned up.
506 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
507 Also inotify support is mandatory now to run udev.
509 The format of the queue exported by the udev damon has changed. There is
510 no longer a /dev/.udev/queue/ directory. The current event queue can be
511 accessed with udevadm settle and libudedv.
513 Libudev does not have the unstable API header anymore. From now on,
514 incompatible changes will be handled by bumping the library major version.
516 To build udev from the git tree gtk-doc is needed now. The tarballs will
517 build without it and contain the pre-built documentation. An online copy
519 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
521 The tools from the udev-extras repository have been merged into the main
522 udev repository. Some of the extras have larger external dependencies, and
523 they can be disabled with the configure switch --disable-extras.
529 The program vol_id and the library libvolume_id are removed from the
530 repository. Libvolume_id is merged with libblkid from the util-linux-ng
531 package. Persistent disk links for label and uuid depend on the
532 util-linux-ng version (2.15) of blkid now. Older versions of blkid
533 can not be used with udev.
535 Libudev allows to subscribe to udev events. To prevent unwanted messages
536 to be delivered, and waking up the subscribing process, a filter can be
537 installed, to drop messages inside a kernel socket filter. The filters
538 match on the <subsytem>:<devtype> properties of the device.
539 This is part of the ongoing effort to replace HAL, and switch current
540 users over to directly use libudev.
541 Libudev is still marked as experimental, and its interface might
542 eventually change if needed, but no major changes of the currently exported
543 interface are expected anymore, and a first stable release should happen
546 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
547 is not supported since while and udevd will log an error message at
548 startup. It should still be able to boot-up, but advanced rules and system
549 services which depend on the information not available in the old sysfs
550 format will fail to work correctly.
552 DVB device naming is supplied by the kernel now. In case older kernels
553 need to be supported, the old shell script should be added to a compat
560 The processed udev events get send back to the netlink socket. Libudev
561 provides access to these events. This is work-in-progress, to replace
562 the DeviceKit daemon functionality directly with libudev. There are
563 upcoming kernel changes to allow non-root users to subcribe to these
570 "udevadm settle" now optionally accepts a range of events to wait for,
571 instead of waiting for "all" events.
577 The installed watch for block device metadata changes is now removed
578 during event hadling, because some (broken) tools may be called from udev
579 rules and (wrongly) open the device with write access. After the finished
580 event handling the watch is restored.
586 Device nodes can be watched for changes with inotify with OPTIONS="watch".
587 If closed after being opened for writing, a "change" uevent will occur.
588 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
594 The udevadm test command has no longer a --force option, nodes and symlinks
595 are always updated with a test run now.
597 The udevd daemon can be started with --resolve-names=never to avoid all user
598 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
599 lookup user and groups every time events are handled.
605 We are currently merging the Ubuntu rules in the udev default rules,
606 and get one step closer to provide a common Linux /dev setup, regarding
607 device names, symlinks, and default device permissions. On udev startup,
608 we now expect the following groups to be resolvable to their ids with
610 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
611 LDAP setups need to make sure, that these groups are always resolvable at
612 bootup, with only the rootfs mounted, and without network access available.
614 Some systems may need to add some new, currently not used groups, or need
615 to add some users to new groups, but the cost of this change is minimal,
616 compared to the pain the current, rather random, differences between the
617 various distributions cause for upstream projects and third-party vendors.
619 In general, "normal" users who log into a machine should never be a member
620 of any such group, but the device-access should be managed by dynamic ACLs,
621 which get added and removed for the specific users on login/logout and
622 session activity/inactivity. These groups are only provided for custom setups,
623 and mainly system services, to allow proper privilege separation.
624 A video-streaming daemon uid would be a member of "audio" and "video", to get
625 access to the sound and video devices, but no "normal" user should ever belong
626 to the "audio" group, because he could listen to the built-in microphone with
627 any ssh-session established from the other side of the world.
629 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
630 which do not depend on the kernel device name. As usual, unique
631 devices - only a single one per product connected, or a real
632 USB serial number in the device - are always found with the same
633 name in the by-id/ directory.
634 Completely identical devices may overwrite their names in by-id/
635 and can only be found reliably in the by-path/ directory. Devices
636 specified by by-path/ must not change their connection, like the
637 USB port number they are plugged in, to keep their name.
639 To support some advanced features, Linux 2.6.22 is the oldest supported
640 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
641 supported. Older kernels should still work, and devices nodes should be
642 reliably created, but some rules and libudev will not work correctly because
643 the old kernels do not provide the expected information or interfaces.
649 Fix for a possible segfault while swapping network interface names in udev
656 The group "video" is part of the default rules now.
660 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
661 block devices in some cases. No common distro uses this option anymore,
662 and we do not get enough testing for this and recent udev versions. If
663 this option is not needed to run some old distro with a new kernel,
664 it should be disabled in the kernel config.
666 Bugfix for the $links substitution variable, which may crash if no links
667 are created. This should not happen in usual setups because we always
668 create /dev/{block,char}/ links.
670 The strings of the parsed rules, which are kept in memory, no longer
671 contain duplicate entries, or duplicate tails of strings. This, and the
672 new rules parsing/matching code reduces the total in-memory size of
673 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
676 The export of DEVTYPE=disk/partition got removed from the default
677 rules. This value is available from the kernel. The pnp shell script
678 modprobe hack is removed from the default rules. ACPI devices have _proper_
679 modalias support and take care of the same functionality.
680 Installations which support old kernels, but install current default
681 udev rules may want to add that to the compat rules file.
683 Libvolume_id now always probes for all known filesystems, and does not
684 stop at the first match. Some filesystems are marked as "exclusive probe",
685 and if any other filesytem type matches at the same time, libvolume_id
686 will, by default, not return any probing result. This is intended to prevent
687 mis-detection with conflicting left-over signatures found from earlier
688 file system formats. That way, we no longer depend on the probe-order
689 in case of multiple competing signatures. In some setups the kernel allows
690 to mount a volume with just the old filesystem signature still in place.
691 This may damage the new filesystem and cause data-loss, just by mounting
692 it. Because volume_id can not decide which one the correct signature is,
693 the wrong signatures need to be removed manually from the volume, or the
694 volume needs to be reformatted, to enable filesystem detection and possible
699 Fix segfault if compiled without optimization and dbg() does not get
700 compiled out and uses variables which are not available.
704 Bugfixes. (And maybe new bugs. :))
706 The rule matching engine got converted from a rule list to a token
707 array which reduced the in-memory rules representation of a full
708 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
709 Limits like 5 ENV and ATTR matches, and one single instance for most
710 other keys per rule are gone.
712 The NAME assignment is no longer special cased. If later rules assign
713 a NAME value again, the former value will be overwritten. As usual
714 for most other keys, the NAME value can be protected by doing a final
715 assignment with NAME:="<value>".
717 All udev code now uses libudev, which is also exported. The library
718 is still under development, marked as experimental, and its interface
719 may change as long as the DeviceKit integration is not finished.
721 Many thanks to Alan Jenkins for his continuous help, and finding and
722 optimizing some of the computing expensive parts.
728 Kernel devices and device nodes are connected now by reverse indizes in
729 /sys and /dev. A device number retrieved by a stat() or similar, the
730 kernel device directory can be found by looking up:
731 /sys/dev/{block,char}/<maj>:<min>
732 and the device node of the same device by looking up:
733 /dev/{block,char}/<maj>:<min>
737 Fix recently introduced bug, which caused a compilation without large
738 file support, where vol_id does not recognize raid signatures at the end
741 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
742 Seems some kernel versions prevent the creation of the ieee-* links,
743 so people used the scsi-* link which disappeared now.
745 More libudev work. Almost all udevadm functionality comes from libudev
748 udevadm trigger has a new option --type, which allows to trigger events
749 for "devices", for "subsystems", or "failed" devices. The old option
750 --retry-failed" still works, but is no longer mentioned in the man page.
756 The udevadm info --device-id-of-file= output has changed to use
757 the obvious format. Possible current users should use the --export
758 option which is not affected.
760 The old udev commands symlinks to udevadm are not installed, if
761 these symlinks are used, a warning is printed.
767 Optical drive's media is no longer probed for raid signatures,
768 reading the end of the device causes some devices to malfunction.
769 Also the offset of the last session found is used now to probe
772 The volume_id library got a major version number update to 1,
773 some deprecated functions are removed.
775 A shared library "libudev" gets installed now to provide access
776 to udev device information. DeviceKit, the successor of HAL, will
777 need this library to access the udev database and search sysfs for
779 The library is currently in an experimental state, also the API is
780 expected to change, as long as the DeviceKit integration is not
785 We use ./configure now. See INSTALL for details. Current
788 "/usr" - prefix for man pages, include files
790 "" - the root filesystem, prefix for libs and binaries
794 "lib" - directory name for libraries, not a path name
795 multilib 64bit systems may use "lib64" instead of "lib"
797 compile-in verbose debug messages
799 disable all logging and compile-out all log strings
801 link against SELInux libraries, to set the expected context
804 In the default rules, the group "disk" gets permissions 0660 instead
805 of 0640. One small step closer to unify distro rules. Some day, all
806 distros hopefully end up with the same set of rules.
808 No symlinks to udevadm are installed anymore, if they are still needed,
809 they should be provided by the package.
815 Default udev rules, which are not supposed to be edited by the user, should
816 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
817 the udev package and will be replaced with an update. Udev will pick up rule
819 /lib/udev/rules.d/ - default installed rules
820 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
821 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
822 It does not matter in which directory a rule file lives, all files are sorted
825 To help creating /dev/root, we have now:
826 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
829 In case the current --device-id-of-file is already used, please switch to
830 the --export format version, it saves the output parsing and the old
831 format will be changed to use ':' as a separator, like the format in the
836 Fix cdrom_id to properly recognize blank media.
842 Tape drive id-data is queried from /dev/bsg/* instead of the tape
843 nodes. This avoids rewinding tapes on open().
849 The symlinks udevcontrol and udevtrigger are no longer installed by
852 The scsi_id program does not depend on sysfs anymore. It can speak
853 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
854 data, which should solve some old problems with tape devices, where
855 we better do not open all tape device nodes to identify the device.
861 The cdrom_id program is replaced by an advanced version, which can
862 detect most common device types, and also properties of the inserted
863 media. This is part of moving some basic functionality from HAL into
864 udev (and the kernel).
870 The last WAIT_FOR_SYSFS rule is removed from the default rules.
872 The symlinks to udevadm for the debugging tools: udevmonitor and
873 udevtest are no longer created.
875 The symlinks to the udevadm man page for the old tool names are
878 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
879 should be prefixed with '@' to indicate that the path is not a
890 Udevstart is removed from the tree, it did not get installed for
891 a long time now, and is long replaced by trigger and settle.
897 All udev tools are merged into a single binary called udevadm.
898 The old names of the tools are built-in commands in udevadm now.
899 Symlinks to udevadm, with the names of the old tools, provide
900 the same functionality as the standalone tools. There is also
901 only a single udevadm.8 man page left for all tools.
903 Tools like mkinitramfs should be checked, if they need to include
904 udevadm in the list of files.
914 The etc/udev/rules.d/ directory now contains a default set of basic
915 udev rules. This initial version is the result of a rules file merge
916 of Fedora and openSUSE. For these both distros only a few specific
917 rules are left in their own file, named after the distro. Rules which
918 are optionally installed, because they are only valid for a specific
919 architecture, or rules for subsystems which are not always used are
920 in etc/udev/packages/.
926 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
927 actions by dynamically created rules.
929 SYMLINK=="<value>" matches agains the entries in the list of
930 currently defined symlinks. The links are not created in the
931 filesystem at that point in time, but the values can be matched.
933 RUN{ignore_error}+="<program>" will ignore any exit code from the
934 program and not record as a failed event.
940 Final merge of patches/features from the Ubuntu package.
946 Control characters in filesystem label strings are no longer silenty
947 removed, but hex-encoded, to be able to uniquely identify the device
948 by its symlink in /dev/disk/by-label/.
949 If libvolume_id is used by mount(8), LABEL= will work as expected,
950 if slashes or other characters are used in the label string.
952 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
953 can be specified now. The TEST key accepts an optional mode mask
954 TEST{0100}=="<is executable file>".
956 Scsi_id now supports a mode without expecting scsi-specific sysfs
957 entries to allow the extraction of cciss-device persistent properties.
963 In the future, we may see uuid's which are just simple character
964 strings (see the DDF Raid Specification). For that reason vol_id now
965 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
966 the creation of symlinks, the *_SAFE values ensure, that no control
967 or whitespace characters are used in the filename.
969 Possible users of libvolume_id, please use the volume_id_get_* functions.
970 The public struct will go away in a future release of the library.
976 Removal of useless extras/eventrecorder.sh.
986 The directory multiplexer for dev.d/ and hotplug.d are finally removed
987 from the udev package.
993 Symlinks can have priorities now, the priority is assigned to the device
994 and specified with OPTIONS="link_priority=100". Devices with higher
995 priorities overwrite the symlinks of devices with lower priorities.
996 If the device that currently owns the link, goes away, the symlink
997 will be removed, and recreated, pointing to the next device with the
998 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
999 more reliable, if multiple devices contain the same metadata and overwrite
1002 The dasd_id program is removed from the udev tree, and dasdinfo, with the
1003 needed rules, are part of the s390-tools now.
1005 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
1006 we may get the scsi sysfs mess fixed some day, and this will only catch
1007 the devices we are looking for.
1009 USB serial numbers for storage devices have the target:lun now appended,
1010 to make it possibble to distinguish broken multi-lun devices with all
1011 the same SCSI identifiers.
1013 Note: The extra "run_directory" which searches and executes stuff in
1014 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
1015 with the next release. Make sure, that you don't use it anymore, or
1016 provides your own implementation of that inefficient stuff.
1017 We are tired of reports about a "slow udev", because these directories
1018 contain stuff, that runs with _every_ event, instead of using rules,
1019 that run programs only for the matching events.
1029 DRIVER== will match only for devices that actually have a real
1030 driver. DRIVERS== must be used, if parent devices should be
1031 included in the match.
1033 Libvolume_id's "linux_raid" detection needed another fix.
1041 Add additional check to volume_id detection of via_raid, cause
1042 some company decided to put a matching pattern all over the empty
1043 storage area of their music players.
1047 Fix path_id for SAS devices.
1051 The udev daemon can be started with --debug-trace now, which will
1052 execute all events serialized to get a chance to catch a possible
1053 action that crashes the box.
1055 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1056 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1057 are excluded from the warning. Referencing parent attributes directly
1058 may break when something in the kernel driver model changes. Udev will
1059 just find the attribute by walking up the parent chain.
1061 Udevtrigger now sorts the list of devices depending on the device
1062 dependency, so a "usb" device is triggered after the parent "pci"
1067 Revert persistent-storage ata-serial '_' '-' replacement.
1073 Udevtrigger can now filter the list of devices to be triggered. Matches
1074 for subsystems or sysfs attributes can be specified.
1076 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1077 zero-sized files to avoid pointing to /sys and confuse broken tools which
1078 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1081 The rules and scripts to create udev rules for persistent network
1082 devices and optical drives are in the extras/rules_generator directory
1083 now. If you use something similar, please consider replacing your own
1084 version with this, to share the support effort. The rule_generator
1085 installs its own rules into /etc/udev/rules.d.
1087 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1088 the rule_generator depends on cdrom_id to be called in an earlier rule.
1094 Renaming of some key names (the old names still work):
1095 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1096 (The behavior of the key DRIVER will change soon in one of the next
1097 releases, to match only the event device, please switch to DRIVERS
1098 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1100 With the new key names, we have a more consistent and simpler scheme.
1101 We can match the properties of the event device only, with: KERNEL,
1102 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1103 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1104 longer mentioned in the man page and should be switched in the rule
1107 ATTR{file}="value" can be used now, to write to a sysfs file of the
1108 event device. Instead of:
1109 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1111 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1113 All the PHYSDEV* keys are deprecated and will be removed from a
1115 PHYDEVPATH - is the path of a parent device and should not be
1117 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1118 matched with SUBSYSTEMS==
1119 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1120 Newer kernels will have DRIVER in the environment,
1121 for older kernels udev puts in. Class device will
1122 no longer carry this property of a parent and
1123 DRIVERS== can be used to match such a parent value.
1124 Note that ENV{DRIVER} is only available for a few bus devices, where
1125 the driver is already bound at device event time. On coldplug, the
1126 events for a lot devices are already bound to a driver, and they will have
1127 that value set. But on hotplug, at the time the kernel creates the device,
1128 it can't know what driver may claim the device after that, therefore
1129 in most cases it will be empty.
1131 Failed events should now be re-triggered with:
1132 udevtrigger --retry-failed.
1133 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1134 files private to the udev tools. We may need to switch the current symlink
1135 target, cause some obviously broken tools try to scan all files in /dev
1136 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1137 million times. This takes ages on slow boxes.
1139 The udevinfo attribute walk (-a) now works with giving a device node
1140 name (-n) instead of a devpath (-p). The query now always works, also when
1141 no database file was created by udev.
1143 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1144 getpwnam() and getgrnam() now. One of the next releases will depend on
1145 fnmatch() and may use getopt_long().
1149 Bugfixes and small improvements.
1153 Fix path_id for recent kernels.
1159 Added support for swapping network interface names, by temporarily
1160 renaming the device and wait for the target name to become free.
1164 The built-in MODALIAS key and substitution is removed.
1168 The binary firmware helper is replaced by the usual simple
1169 shell script. Udevsend is removed from the tree.
1177 Some more keys require the correct use of '==' and '=' depending
1178 on the kind of operation beeing an assignment or a match. Rules
1179 with invalid operations are skipped and logged to syslog. Please
1180 test with udevtest if the parsing of your rules throws errors and
1181 fix possibly broken rules.
1185 Provide "udevsettle" to wait for all current udev events to finish.
1186 It also watches the current kernel netlink queue by comparing the
1187 even sequence number to make sure that there are no current pending
1188 events that have not already arrived in the daemon.
1192 Fix rule to skip persistent rules for removable IDE devices, which
1193 also skipped optical IDE drives.
1195 All *_id program are installed in /lib/udev/ by default now.
1197 No binary is stripped anymore as this should be done in the
1198 packaging process and not at build time.
1200 libvolume_id is provided as a shared library now and vol_id is
1201 linked against it. Also one of the next HAL versions will require
1202 this library, and the HAL build process will also require the
1203 header file to be installed. The copy of the same code in HAL will
1204 be removed to have only a single copy left on the system.
1208 Add persistent links for SCSI tapes. The rules file is renamed
1209 to 60-persistent-storage.rules.
1211 Create persistent path for usb devices. Can be used for all sorts
1212 of devices that can't be distinguished by other properties like
1213 multiple identical keyboards and mice connected to the same box.
1215 Provide "udevtrigger" program to request events on coldplug. The
1216 shell script is much too slow with thousends of devices.
1220 Fix persistent disk rules to exclude removable IDE drives.
1222 Warn if %e, $modalias or MODALIAS is used.
1226 Fix queue export, which wasn't correct for subsequent add/remove
1227 events for the same device.
1231 Fix cramfs detection on big endian.
1233 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1238 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1239 attributes were only checked at the parent device that matched the
1240 by BUS requested subsystem. Fix it to also look at the device we
1241 received the event for.
1243 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1248 Fix a bug where NAME="" would prevent RUN from beeing executed.
1250 RUN="/bin/program" does not longer automatically add the subsystem
1251 as the first parameter. This is from the days of /sbin/hotplug
1252 which is dead now and it's just confusing to need to add a space at
1253 the end of the program name to prevent this.
1254 If you use rules that need the subsystem as the first parameter,
1255 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1256 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1260 The udev man page has moved to udev(7) as it does not describe a command
1261 anymore. The programs udev, udevstart and udevsend are no longer installed
1262 by default and must be copied manually, if they should be installed or
1263 included in a package.
1265 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1266 the ignore rule was applied.
1268 More preparation for future sysfs changes. usb_id and scsi_id no longer
1269 depend on a magic order of devices in the /devices chain. Specific devices
1270 should be requested by their subsytem.
1272 This will always find the scsi parent device without depending on a specific
1274 dev = sysfs_device_get(devpath);
1275 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1277 The "device" link in the current sysfs layout will be automatically
1278 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1279 parent in the devpath. If a device is requested by it's symlink, like all
1280 class devices in the new sysfs layout will look like, it gets automatically
1281 resolved and substituted with the real devpath and not the symlink path.
1284 A similar logic must be applied to _all_ sysfs users, including
1285 scripts, that search along parent devices in sysfs. The explicit use of
1286 the "device" link must be avoided. With the future sysfs layout all
1287 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1288 back to the "class" or the "bus". The layout of the parent devices in
1289 /devices is not necessarily expected to be stable across kernel releases and
1290 searching for parents by their subsystem should make sysfs users tolerant
1291 for changed parent chains.
1295 Prepare udev to work with the experimental kernel patch, that moves
1296 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1298 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1299 moving the class devices to /sys/devices.
1301 Thanks again to Marco for help finding a hopefully nice compromise
1302 to make %b simpler and working again.
1306 Complete removal of libsysfs, replaced by simple helper functions
1307 which are much simpler and a bit faster. The udev daemon operatesentirely
1308 on event parameters and does not use sysfs for simple rules anymore.
1309 Please report any new bugs/problems, that may be caused by this big
1310 change. They will be fixed immediately.
1312 The enumeration format character '%e' is deprecated and will be
1313 removed sometimes from a future udev version. It never worked correctly
1314 outside of udevstart, so we can't use it with the new parallel
1315 coldplug. A simple enumeration is as useless as the devfs naming
1316 scheme, just get rid of both if you still use it.
1318 MODALIAS and $modalias is not needed and will be removed from one of
1319 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1320 the sysfs "modalias" value.
1322 Thanks a lot to Marco for all his help on finding and fixing bugs.
1326 Let scsi_id request libata drive serial numbers from page 0x80.
1328 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1329 added /dev/disk/by-name/* for device mapper device names.
1331 Removed %e from the man page. It never worked reliably outside
1332 of udevstart and udevstart is no longer recommended to use.
1336 Symlinks are now exported to the event environment. Hopefully it's no
1337 longer needed to run udevinfo from an event process, like it was
1338 mentioned on the hotplug list:
1339 UDEV [1134776873.702967] add@/block/sdb
1342 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1346 Fix a problem if udevsend is used as the hotplug handler and tries to use
1347 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1348 and this kind of problems will hopefully go away soon.
1352 All built-in logic to work around bad sysfs timing is removed with this
1353 version. The need to wait for sysfs files is almost fixed with a kernel
1354 version that doesn't work with this udev version anyway. Until we fix
1355 the timing of the "bus" link creation, the former integrated logic should
1356 be emulated by a rule placed before all other rules:
1357 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1359 The option "udev_db" does no longer exist. All udev state will be in
1360 /$udev_root/.udev/ now, there is no longer an option to set this
1362 If the init script or something else used this value, just depend on
1363 this hardcoded path. But remember _all_content_ of this directory is
1364 still private to udev and can change at any time.
1366 Default location for rule sripts and helper programs is now: /lib/udev/.
1367 Everything that is not useful on the commandline should go into this
1368 directory. Some of the helpers in the extras folder are installed there
1369 now. The rules need to be changed, to find the helpers there.
1371 Also /lib/udev/devices is recommended as a directory where packages or
1372 the user can place real device nodes, which get copied over to /dev at
1373 every boot. This should replace the various solutions with custom config
1376 Udevsend does no longer start the udev daemon. This must be done with
1377 the init script that prepares /dev on tmpfs and creates the initial nodes,
1378 before starting the daemon.
1382 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1385 The copy of klibc is removed. A systemwide installed version of klibc
1386 should be used to build a klibc udev now.
1390 NAME="" will not create any nodes, but execute RUN keys. To completely
1391 ignore an event the OPTION "ignore_device" should be used.
1393 After removal of the reorder queue, events with a TIMEOUT can be executed
1394 without any queuing now.
1398 Fixed bug in udevd, if inotify is not available. We depend on netlink
1399 uevents now, kernels without that event source will not work with that
1400 version of udev anymore.
1404 The rule parsing happens now in the daemon once at startup, all udev
1405 event processes inherit the already parsed rules from the daemon.
1406 It is shipped with SUSE10.0 and reduces heavily the system load at
1407 startup. The option to save precompiled rules and let the udev process
1408 pick the them up is removed, as it's no longer needed.
1410 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1411 device. Libsysfs is changed to "translate" the requested link into the
1412 real device path, as it would happen with the hotplug event. Otherwise
1413 device removal and the udev database will not work.
1415 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1418 A few improvements for vol_id, the filesytem probing code.
1422 Fix a stupid typo in extras/run_directory for "make install".
1424 scsi_id creates the temporary devnode now in /dev for usage with a
1425 non-writable /tmp directory.
1427 The uevent kernel socket buffer can carry app. 50.000 events now,
1428 let's see who can break this again. :)
1430 The upcoming kernel will have a new input driver core integration.
1431 Some class devices are now symlinks to the real device. libsysfs
1432 needs a fix for this to work correctly. Udevstart of older udev
1433 versions will _not_ create these devices!
1437 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1442 A bunch of mostly trivial bugfixes. From now on no node name or
1443 symlink name can contain any character than plain whitelisted ascii
1444 characters or validated utf8 byte-streams. This is needed for the
1445 /dev/disk/by-label/* links, because we import untrusted data and
1446 export it to the filesystem.
1450 More bugfixes. If udevd was started from the kernel, we don't
1451 have stdin/stdout/stderr, which broke the forked tools in some
1456 Bugfix. udevstart event ordering was broken for a long time.
1457 The new run_program() uncovered it, because /dev/null was not
1458 available while we try to run external programs.
1459 Now udevstart should create it before we run anything.
1463 Minor bugfixes and some distro rules updates. If you don't have the
1464 persistent disk rules in /dev/disk/by-*/* on your distro, just
1465 grab it from here. :)
1469 We can use socket communication now to pass events from udev to
1471 RUN+="socket:/org/freedesktop/hal/udev_event"
1472 will pass the whole udev event to the HAL daemon without the need
1473 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1477 Mostly bugfixes and see ChangeLog.
1479 The test for the existence of an environment value should be
1481 ENV{KEY}=="*" to ENV{KEY}=="?*"
1482 because "*" will not fail anymore, if the key does not exist or
1487 Bugfixes and a few tweaks described in the ChangeLog.
1491 Mostly a Bugfix release.
1493 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1494 timing with custom rules.
1498 We changed the internal rule storage format. Our large rule files took
1499 2 MB of RAM, with the change we are down to 99kB.
1501 If the device-node has been created with default name and no symlink or
1502 options are to remenber, it is not longer stored in the udevdb. HAL will
1503 need to be updated to work correctly with that change.
1505 To overrride optimization flags, OPTFLAGS may be used now.
1513 Major changes happened with this release. The goal is to take over the
1514 complete kernel-event handling and provide a more efficient way to dispatch
1515 kernel events. Replacing most of the current shell script logic and the
1516 kernel forked helper with a netlink-daemon and a rule-based event handling.
1518 o udevd listens to netlink events now. The first valid netlink event
1519 will make udevd ignore any message from udevsend that contains a
1520 SEQNUM, to avoid duplicate events. The forked events can be disabled
1522 echo "" > /proc/sys/kernel/hotplug
1523 For full support, the broken input-subsytem needs to be fixed, not to
1524 bypass the driver core.
1526 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1527 removed from udev itself and must be emulated by calling small
1528 helper binaries provided in the extras folder:
1529 make EXTRAS=extras/run_directory/
1530 will build udev_run_devd and udev_run_hotplugd, which can be called
1531 from a rule if needed:
1532 RUN+="/sbin/udev_run_hotplugd"
1533 The recommended way to handle this is to convert all the calls from
1534 the directories to explicit udev rules and get completely rid of the
1535 multiplexing. (To catch a ttyUSB event, you now no longer need to
1536 fork and exit 300 tty script instances you are not interested in, it
1537 is just one rule that matches exactly the device.)
1539 o udev handles now _all_ events not just events for class and block
1540 devices, this way it is possible to control the complete event
1541 behavior with udev rules. Especially useful for rules like:
1542 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1544 o As used in the modalias rule, udev supports now textual
1545 substitution placeholder along with the usual format chars. This
1546 needs to be documented, for now it's only visible in udev_rules_parse.c.
1548 o The rule keys support now more operations. This is documented in the
1549 man page. It is possible to add values to list-keys like the SYMLINK
1550 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1551 Also "final"-assignments are supported by using KEY:="value", which will
1552 prevent changing the key by any later rule.
1554 o kernel 2.6.12 has the "detached_state" attribute removed from
1555 sysfs, which was used to recognize sysfs population. We switched that
1556 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1557 Running this udev version on older kernels may cause a short delay for
1560 o To provide infrastructure for persistent device naming, the id programs:
1561 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1562 to export the probed data in environment key format:
1563 pim:~ # /sbin/ata_id --export /dev/hda
1564 ID_MODEL=HTS726060M9AT00
1565 ID_SERIAL=MRH401M4G6UM9B
1566 ID_REVISION=MH4OA6BA
1568 The following rules:
1569 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1570 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1573 kay@pim:~> tree /dev/disk
1576 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1577 | `-- IBM-Memory_Key -> ../../sda
1579 | |-- swap -> ../../hda1
1580 | |-- date -> ../../sda1
1581 | `-- home -> ../../hda3
1583 |-- 2E08712B0870F2E7 -> ../../hda3
1584 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1585 |-- E845-7A89 -> ../../sda1
1586 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1588 The IMPORT= operation will import these keys in the environment and make
1589 it available for later PROGRAM= and RUN= executed programs. The keys are
1590 also stored in the udevdb and can be queried from there with one of the
1593 o A few binaries are silently added to the repository, which can be used
1594 to replay kernel events from initramfs instead of using coldplug. udevd
1595 can be instructed now to queue-up events while the stored events from
1596 initramfs are filled into the udevd-queue. This code is still under
1597 development and there is no documentation now besides the code itself.
1598 The additional binaries get compiled, but are not installed by default.
1600 o There is also a temporary fix for a performance problem where too many
1601 events happen in parallel and every event needs to parse the rules.
1602 udev can now read precompiled rules stored on disk. This is likely to be
1603 replaced by a more elegant solution in a future udev version.
1607 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1608 Fix for libsysfs not to expect this file was added.
1612 All rules are applied now, but only the first matching rule with a NAME-key
1613 will be applied. All later rules with NAME-key are completely ignored. This
1614 way system supplied symlinks or permissions gets applied to user-defined
1618 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1619 to some rules, to keep the old behavior.
1621 The rules are read on "remove"-events too. That makes is possible to match
1622 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1623 instruct udev to ignore an event (OPTIONS="ignore_device").
1624 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1626 The new RUN-key supports rule-based execution of programs after device-node
1627 handling. This is meant as a general replacement for the dev.d/-directories
1628 to give fine grained control over the execution of programs.
1630 The %s{}-sysfs format char replacement values are searched at any of the
1631 devices in the device chain now, not only at the class-device.
1633 We support log priority levels now. The value udev_log in udev.conf is used
1634 to determine what is printed to syslog. This makes it possible to
1635 run a version with compiled-in debug messages in a production environment
1636 which is sometimes needed to find a bug.
1637 It is still possible to supress the inclusion of _any_ syslog usage with
1638 USE_LOG=false to create the smallest possible binaries if needed.
1639 The configured udev_log value can be overridden with the environment variable
1644 Possible use of a system-wide klibc:
1645 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1646 will link against an external klibc and our own version will be ignored.
1650 We support an unlimited count of symlinks now.
1652 If USE_STATIC=true is passed to a glibc build, we link statically and use
1653 a built-in userdb parser to resolve user and group names.
1655 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1656 we walk up the chain of physical devices to find a match.
1658 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1659 easy to skip certain attribute matches without composing rules with weird
1660 character class negations like:
1661 KERNEL="[!s][!c][!d]*"
1662 this can now be replaced with:
1664 The current simple '=' is still supported, and should work as it does today,
1665 but existing rules should be converted if possible, to be better readable.
1667 We have new ENV{}== key now, to match against a maximum of 5 environment
1670 udevstart is its own binary again, because we don't need co carry this araound
1671 with every forked event.