3 The udev-acl tool is no longer provided, it will be part of a future
4 ConsoleKit release. On systemd systems, advanced ConsoleKit and udev-acl
5 functionality are provided by systemd.
7 Rules files in /etc/udev/rules.s/ with the same name as rules files in
8 /run/udev/rules.d/ now always have precedence. The stack of files is now:
9 /usr/lib (package), /run (runtime, auto-generated), /etc (admin), while
10 the later ones override the earlier ones. In other words: the admin has
16 Require kmod version 5.
18 Provide /dev/cdrom symlink for /dev/sr0.
22 Fix for ID_PART_ENTRY_* property names, added by the blkid built-in. The
23 fix is needed for udisk2 to operate properly.
25 Fix for skipped rule execution when the kernel has removed the device
26 node in /dev again, before the event was even started. The fix is needed
27 to run device-mapper/LVM events properly.
29 Fix for the man page installation, which was skipped when xsltproc was not
34 Bugfix for $name resolution, which broke at least some keymap handling.
38 Bugfix for the firmware loading behavior with kernel modules which
39 try to load firmware in the module_init() path. The blocked event
40 runs into a timout now, which should allow the firmware to be loaded.
42 Bugfix for a wrong DEVNAME= export, which breaks at least the udev-acl
45 Bugfix for missing ID_ properties for GPT partitions.
47 The RUN+="socket:.." option is deprecated and should not be used. A warning
48 during rules parsing is printed now. Services which listen to udev events,
49 need to subscribe to the netlink messages with libudev and not let udev block
50 in the rules execution until the message is delivered.
54 Bugfix for rule_generator instalation.
58 The 'devtmpfs' filesystem is required now, udev will not create or delete
59 device nodes anymore, it only adjusts permissions and ownership of device
60 nodes and maintains additional symlinks.
62 A writable /run directory (ususally tmpfs) is required now for a fully
63 functional udev, there is no longer a fallback to /dev/.udev.
65 The default 'configure' install locations have changed. Packages for systems
66 with the historic / vs. /usr split need to be adapted, otherwise udev will
67 be installed in /usr and not work properly. Example configuration options
68 to install things the traditional way are in INSTALL.
70 The default install location of the 'udevadm' tool moved from 'sbin'
71 to /usr/bin. Some tools expect udevadm in 'sbin', a symlink to udevadm
72 needs to be manually created if needed, or --bindir=/sbin be specified.
74 The expected value of '--libexecdir=' has changed and must no longer contain
77 Kernel modules are now loaded directly by linking udev to 'libkmod'. The
78 'modprobe' tool is no longer executed by udev.
80 The 'blkid' tool is no longer executed from udev rules. Udev links
81 directly to libblkid now.
83 Firmware is loaded natively by udev now, the external 'firmware' binary
86 All built-in tools can be listed and tested with 'udevadm test-builtin'.
88 The 'udevadm control --reload-rules' option has been renamed to '--reload'.
89 It now also reloads the kernel module configuration.
91 The systemd socket files use PassCredentials=yes, which is available in
94 The udev build system only creates a .xz tarball now.
96 All tabs in the source code used for indentation are replaced by spaces now. :)
106 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
107 and non-dracut initramfs image generators need to change the init
108 scripts. Alternatively the udev build needs to move udevd back to
109 /sbin or create a symlink in /sbin, which is not done by default.
111 The path_id, usb_id, input_id tools are built-in commands now and
112 the stand-alone tools do not exist anymore. Static lists of file in
113 initramfs generators need to be updated. For testing, the commands
114 can still be executed standalone with 'udevadm test-builtin <cmd>'.
116 The fusectl filesystem is no longer mounted directly from udev.
117 Systemd systems will take care of mounting fusectl and configfs
118 now. Non-systemd systems need to ship their own rule if they
119 need these filesystems auto-mounted.
121 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
123 The support for 'udevadm trigger --type=failed, and the
124 RUN{fail_event_on_error} attribute was removed.
126 The udev control socket is now created in /run/udev/control
127 and no longer as an abstract namespace one.
129 The rules to create persistent network interface and cdrom link
130 rules automatically in /etc/udev/rules.d/ have been disabled by
131 default. Explicit configuration will be required for these use
132 cases, udev will no longer try to write any persistent system
133 configuration from a device hotplug path.
139 The udev-acl extra is no longer enabled by default now. To enable it,
140 --enable-udev_acl needs to be given at ./configure time. On systemd
141 systems, the udev-acl rules prevent it from running as the functionality
142 has moved to systemd.
148 Udev now enables kernel media-presence polling if available. Part
149 of udisks optical drive tray-handling moved to cdrom_id: The tray
150 is locked as soon as a media is detected to enable the receiving
151 of media-eject-request events. Media-eject-request events will
154 Libudev enumerate is now able to enumerate a subtree of a given
157 The mobile-action-modeswitch modeswitch tool was deleted. The
158 functionality is provided by usb_modeswitch now.
164 The systemd service files require systemd version 28. The systemd
165 socket activation make it possible now to start 'udevd' and 'udevadm
166 trigger' in parallel.
170 Fix bug in control message handling, which can lead to a failing
171 udevadm control --exit. Thanks to Jürg Billeter for help tracking
178 We require at least Linux kernel 2.6.32 now. Some platforms might
179 require a later kernel that supports accept4() and similar, or
180 need to backport the trivial syscall wiring to the older kernels.
182 The hid2hci tool moved to the bluez package and was removed.
184 Many of the extras can be --enable/--disabled at ./configure
185 time. The --disable-extras option was removed. Some extras have
186 been disabled by default. The current options and their defaults
187 can be checked with './configure --help'.
193 Udev logs a warning now if /run is not writable at udevd
194 startup. It will still fall back to /dev/.udev, but this is
195 now considered a bug.
197 The running udev daemon can now cleanly shut down with:
198 udevadm control --exit
200 Udev in initramfs should clean the state of the udev database
201 with: udevadm info --cleanup-db which will remove all state left
202 behind from events/rules in initramfs. If initramfs uses
203 --cleanup-db and device-mapper/LVM, the rules in initramfs need
204 to add OPTIONS+="db_persist" for all dm devices. This will
205 prevent removal of the udev database for these devices.
207 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
208 120 seconds per process. If that timeout is reached the spawned
209 process will be killed. The event timeout can be overwritten with
212 If systemd is used, udev gets now activated by netlink data.
213 Systemd will bind the netlink socket which will buffer all data.
214 If needed, such setup allows a seemless update of the udev daemon,
215 where no event can be lost during a udevd update/restart.
216 Packages need to make sure to: systemctl stop udev.socket udev.service
217 or 'mask' udev.service during the upgrade to prevent any unwanted
218 auto-spawning of udevd.
219 This version of udev conflicts with systemd version below 25. The
220 unchanged service files will not wirk correctly.
226 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
227 /run mountpoint is supposed to be a tmpfs mounted during early boot,
228 available and writable to for all tools at any time during bootup,
229 it replaces /var/run/, which should become a symlink some day.
231 If /run does not exist, or is not writable, udev will fall back using
234 On systemd systems with initramfs and LVM used, packagers must
235 make sure, that the systemd and initramfs versions match. The initramfs
236 needs to create the /run mountpoint for udev to store the data, and
237 mount this tmpfs to /run in the rootfs, so the that the udev database
238 is preserved for the udev version started in the rootfs.
240 The command 'udevadm info --convert-db' is gone. The udev daemon
241 itself, at startup, converts any old database version if necessary.
243 The systemd services files have been reorganized. The udev control
244 socket is bound by systemd and passed to the started udev daemon.
245 The udev-settle.service is no longer active by default. Services which
246 can not handle hotplug setups properly need to actively pull it in, to
247 act like a barrier. Alternatively the settle service can be unconditionally
248 'systemctl'enabled, and act like a barrier for basic.target.
250 The fstab_import callout is no longer built or installed. Udev
251 should not be used to mount, does not watch changes to fstab, and
252 should not mirror fstab values in the udev database.
258 New and updated keymaps.
264 The udev database has changed, After installation of a new udev
265 version, 'udevadm info --convert-db' should be called, to let the new
266 udev/libudev version read the already stored data.
268 udevadm now supports quoting of property values, and prefixing of
270 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
273 MY_DEVNAME='/dev/sda'
277 libudev now supports:
278 udev_device_get_is_initialized()
279 udev_enumerate_add_match_is_initialized()
280 to be able to skip devices the kernel has created , but udev has
283 libudev now supports:
284 udev_device_get_usec_since_initialized()
285 to retrieve the "age" of a udev device record.
287 GUdev supports a more generic GUdevEnumerator class, udev TAG
288 handling, device initialization and timestamp now.
290 The counterpart of /sys/dev/{char,block}/$major:$minor,
291 /dev/{char,block}/$major:$minor symlinks are now unconditionally
292 created, even when no rule files exist.
294 New and updated keymaps.
300 GUdev moved from /usr to /.
310 Persistent network naming rules are disabled inside of Qemu/KVM now.
312 New and updated keymaps.
314 Udev gets unconditionally enabled on systemd installations now. There
315 is no longer the need to to run 'systemctl enable udev.service'.
329 New and fixed keymaps.
331 Install systemd service files if applicable.
337 All distribution specific rules are removed from the udev source tree,
338 most of them are no longer needed. The Gentoo rules which allow to support
339 older kernel versions, which are not covered by the default rules anymore
340 has moved to rules/misc/30-kernel-compat.rules.
346 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
347 was removed from udevd.
349 Udevd now checks the kernel commandline for the following variables:
350 udev.log-priority=<syslog priority>
351 udev.children-max=<maximum number of workers>
352 udev.exec-delay=<seconds to delay the execution of RUN=>
353 to help debuging coldplug setups where the loading of a kernel
354 module crashes the system.
356 The subdirectory in the source tree rules/packages has been renamed to
357 rules/arch, anc contains only architecture specific rules now.
367 Now the udev daemon itself, does on startup:
368 - copy the content of /lib/udev/devices to /dev
369 - create the standard symlinks like /dev/std{in,out,err},
370 /dev/core, /dev/fd, ...
371 - use static node information provided by kernel modules
372 and creates these nodes to allow module on-demand loading
373 - possibly apply permissions to all ststic nodes from udev
374 rules which are annotated to match a static node
376 The default mode for a device node is 0600 now to match the kernel
377 created devtmpfs defaults. If GROUP= is specified and no MODE= is
378 given the default will be 0660.
384 Udev now gradually starts to pass control over the primary device nodes
385 and their names to the kernel, and will in the end only manage the
386 permissions of the node, and possibly create additional symlinks.
387 As a first step NAME="" will be ignored, and NAME= setings with names
388 other than the kernel provided name will result in a logged warning.
389 Kernels that don't provide device names, or devtmpfs is not used, will
390 still work as they did before, but it is strongly recommended to use
391 only the same names for the primary device node as the recent kernel
392 provides for all devices.
396 Fix broken firmware loader search path.
402 "udevadm trigger" defaults to "change" events now instead of "add"
403 events. The "udev boot script" might need to add "--action=add" to
404 the trigger command if not already there, in case the initial coldplug
405 events are expected as "add" events.
407 The option "all_partitons" was removed from udev. This should not be
408 needed for usual hardware. Udev can not safely make assumptions
409 about non-existing partition major/minor numbers, and therefore no
410 longer provide this unreliable and unsafe option.
412 The option "ignore_remove" was removed from udev. With devtmpfs
413 udev passed control over device nodes to the kernel. This option
414 should not be needed, or can not work as advertised. Neither
415 udev nor the kernel will remove device nodes which are copied from
416 the /lib/udev/devices/ directory.
418 All "add|change" matches are replaced by "!remove" in the rules and
419 in the udev logic. All types of events will update possible symlinks
420 and permissions, only "remove" is handled special now.
422 The modem modeswitch extra was removed and the external usb_modeswitch
423 program should be used instead.
425 New and fixed keymaps.
435 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
436 depend on the current sysfs layout and the information not available in the
437 deprecated layout. All remaining support for the deprecated sysfs layout is
442 Fix for a possible endless loop in the new input_id program.
448 The option "ignore_device" does no longer exist. There is no way to
449 ignore an event, as libudev events can not be suppressed by rules.
450 It only prevented RUN keys from being executed, which results in an
451 inconsistent behavior in current setups.
453 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
454 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
457 The support for the deprecated IDE devices has been removed from the
458 default set of rules. Distros who still care about non-libata drivers
459 need to add the rules to the compat rules file.
461 The ID_CLASS property on input devices has been replaced by the more accurate
462 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
463 determined by the new "input_id" prober now. Some devices, such as touchpads,
464 can have several classes. So if you previously had custom udev rules which e. g.
465 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
466 ENV{ID_INPUT_KEYBOARD}=="?*".
472 To support DEVPATH strings larger than the maximum file name length, the
473 private udev database format has changed. If some software still reads the
474 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
475 Please do not port anything to the new format again, everything in /dev/.udev
476 is and always was private to udev, and may and will change any time without
479 Multiple devices claiming the same names in /dev are limited to symlinks
480 only now. Mixing identical symlink names and node names is not supported.
481 This reduces the amount of data in the database significantly.
483 NAME="%k" causes a warning now. It's is and always was completely superfluous.
484 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
487 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
488 if they are not the default. To support older kernels, the NAME= rules need to
489 be added to the compat rules file.
491 Symlinks to udevadm with the old command names are no longer resolved to
492 the udevadm commands.
494 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
497 The option "last_rule" does no longer exist. Its use breaks too many
498 things which expect to be run from independent later rules, and is an idication
499 that something needs to be fixed properly instead.
501 The gudev API is no longer marked as experimental,
502 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
503 is enabled by default now. Various projects already depend on introspection
504 information to bind dynamic languages to the gudev interfaces.
510 The udevadm trigger "--retry-failed" option, which is replaced since quite
511 a while by "--type=failed" is removed.
513 The failed tracking was not working at all for a few releases. The RUN
514 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
515 default is not to track any failing RUN executions.
517 New keymaps, new modem, hid2hci updated.
521 Fix possible crash in udevd when worker processes are busy, rules are
522 changed at the same time, and workers get killed to reload the rules.
528 Properties set with ENV{.FOO}="bar" are marked private by starting the
529 name with a '.'. They will not be stored in the database, and not be
530 exported with the event.
532 Firmware files are looked up in:
533 /lib/firmware/updates/$(uname -r)
534 /lib/firmware/updates
535 /lib/firmware/$(uname -r)
539 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
540 ata_id, instead of scsi_id, is the default tool now for ATA devices.
546 The configure options have changed because another library needs to be
547 installed in a different location. Instead of exec_prefix and udev_prefix,
548 libdir, rootlibdir and libexecdir are used. The Details are explained in
551 Event processes now get re-used after they handled an event. This reduces
552 the number of forks and the pressure on the CPU significantly, because
553 cloned event processes no longer cause page faults in the main daemon.
554 After the events have settled, a few worker processes stay around for
555 future events, all others get cleaned up.
557 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
558 Also inotify support is mandatory now to run udev.
560 The format of the queue exported by the udev damon has changed. There is
561 no longer a /dev/.udev/queue/ directory. The current event queue can be
562 accessed with udevadm settle and libudedv.
564 Libudev does not have the unstable API header anymore. From now on,
565 incompatible changes will be handled by bumping the library major version.
567 To build udev from the git tree gtk-doc is needed now. The tarballs will
568 build without it and contain the pre-built documentation. An online copy
570 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
572 The tools from the udev-extras repository have been merged into the main
573 udev repository. Some of the extras have larger external dependencies, and
574 they can be disabled with the configure switch --disable-extras.
580 The program vol_id and the library libvolume_id are removed from the
581 repository. Libvolume_id is merged with libblkid from the util-linux-ng
582 package. Persistent disk links for label and uuid depend on the
583 util-linux-ng version (2.15) of blkid now. Older versions of blkid
584 can not be used with udev.
586 Libudev allows to subscribe to udev events. To prevent unwanted messages
587 to be delivered, and waking up the subscribing process, a filter can be
588 installed, to drop messages inside a kernel socket filter. The filters
589 match on the <subsytem>:<devtype> properties of the device.
590 This is part of the ongoing effort to replace HAL, and switch current
591 users over to directly use libudev.
592 Libudev is still marked as experimental, and its interface might
593 eventually change if needed, but no major changes of the currently exported
594 interface are expected anymore, and a first stable release should happen
597 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
598 is not supported since while and udevd will log an error message at
599 startup. It should still be able to boot-up, but advanced rules and system
600 services which depend on the information not available in the old sysfs
601 format will fail to work correctly.
603 DVB device naming is supplied by the kernel now. In case older kernels
604 need to be supported, the old shell script should be added to a compat
611 The processed udev events get send back to the netlink socket. Libudev
612 provides access to these events. This is work-in-progress, to replace
613 the DeviceKit daemon functionality directly with libudev. There are
614 upcoming kernel changes to allow non-root users to subcribe to these
621 "udevadm settle" now optionally accepts a range of events to wait for,
622 instead of waiting for "all" events.
628 The installed watch for block device metadata changes is now removed
629 during event hadling, because some (broken) tools may be called from udev
630 rules and (wrongly) open the device with write access. After the finished
631 event handling the watch is restored.
637 Device nodes can be watched for changes with inotify with OPTIONS="watch".
638 If closed after being opened for writing, a "change" uevent will occur.
639 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
645 The udevadm test command has no longer a --force option, nodes and symlinks
646 are always updated with a test run now.
648 The udevd daemon can be started with --resolve-names=never to avoid all user
649 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
650 lookup user and groups every time events are handled.
656 We are currently merging the Ubuntu rules in the udev default rules,
657 and get one step closer to provide a common Linux /dev setup, regarding
658 device names, symlinks, and default device permissions. On udev startup,
659 we now expect the following groups to be resolvable to their ids with
661 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
662 LDAP setups need to make sure, that these groups are always resolvable at
663 bootup, with only the rootfs mounted, and without network access available.
665 Some systems may need to add some new, currently not used groups, or need
666 to add some users to new groups, but the cost of this change is minimal,
667 compared to the pain the current, rather random, differences between the
668 various distributions cause for upstream projects and third-party vendors.
670 In general, "normal" users who log into a machine should never be a member
671 of any such group, but the device-access should be managed by dynamic ACLs,
672 which get added and removed for the specific users on login/logout and
673 session activity/inactivity. These groups are only provided for custom setups,
674 and mainly system services, to allow proper privilege separation.
675 A video-streaming daemon uid would be a member of "audio" and "video", to get
676 access to the sound and video devices, but no "normal" user should ever belong
677 to the "audio" group, because he could listen to the built-in microphone with
678 any ssh-session established from the other side of the world.
680 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
681 which do not depend on the kernel device name. As usual, unique
682 devices - only a single one per product connected, or a real
683 USB serial number in the device - are always found with the same
684 name in the by-id/ directory.
685 Completely identical devices may overwrite their names in by-id/
686 and can only be found reliably in the by-path/ directory. Devices
687 specified by by-path/ must not change their connection, like the
688 USB port number they are plugged in, to keep their name.
690 To support some advanced features, Linux 2.6.22 is the oldest supported
691 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
692 supported. Older kernels should still work, and devices nodes should be
693 reliably created, but some rules and libudev will not work correctly because
694 the old kernels do not provide the expected information or interfaces.
700 Fix for a possible segfault while swapping network interface names in udev
707 The group "video" is part of the default rules now.
711 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
712 block devices in some cases. No common distro uses this option anymore,
713 and we do not get enough testing for this and recent udev versions. If
714 this option is not needed to run some old distro with a new kernel,
715 it should be disabled in the kernel config.
717 Bugfix for the $links substitution variable, which may crash if no links
718 are created. This should not happen in usual setups because we always
719 create /dev/{block,char}/ links.
721 The strings of the parsed rules, which are kept in memory, no longer
722 contain duplicate entries, or duplicate tails of strings. This, and the
723 new rules parsing/matching code reduces the total in-memory size of
724 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
727 The export of DEVTYPE=disk/partition got removed from the default
728 rules. This value is available from the kernel. The pnp shell script
729 modprobe hack is removed from the default rules. ACPI devices have _proper_
730 modalias support and take care of the same functionality.
731 Installations which support old kernels, but install current default
732 udev rules may want to add that to the compat rules file.
734 Libvolume_id now always probes for all known filesystems, and does not
735 stop at the first match. Some filesystems are marked as "exclusive probe",
736 and if any other filesytem type matches at the same time, libvolume_id
737 will, by default, not return any probing result. This is intended to prevent
738 mis-detection with conflicting left-over signatures found from earlier
739 file system formats. That way, we no longer depend on the probe-order
740 in case of multiple competing signatures. In some setups the kernel allows
741 to mount a volume with just the old filesystem signature still in place.
742 This may damage the new filesystem and cause data-loss, just by mounting
743 it. Because volume_id can not decide which one the correct signature is,
744 the wrong signatures need to be removed manually from the volume, or the
745 volume needs to be reformatted, to enable filesystem detection and possible
750 Fix segfault if compiled without optimization and dbg() does not get
751 compiled out and uses variables which are not available.
755 Bugfixes. (And maybe new bugs. :))
757 The rule matching engine got converted from a rule list to a token
758 array which reduced the in-memory rules representation of a full
759 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
760 Limits like 5 ENV and ATTR matches, and one single instance for most
761 other keys per rule are gone.
763 The NAME assignment is no longer special cased. If later rules assign
764 a NAME value again, the former value will be overwritten. As usual
765 for most other keys, the NAME value can be protected by doing a final
766 assignment with NAME:="<value>".
768 All udev code now uses libudev, which is also exported. The library
769 is still under development, marked as experimental, and its interface
770 may change as long as the DeviceKit integration is not finished.
772 Many thanks to Alan Jenkins for his continuous help, and finding and
773 optimizing some of the computing expensive parts.
779 Kernel devices and device nodes are connected now by reverse indizes in
780 /sys and /dev. A device number retrieved by a stat() or similar, the
781 kernel device directory can be found by looking up:
782 /sys/dev/{block,char}/<maj>:<min>
783 and the device node of the same device by looking up:
784 /dev/{block,char}/<maj>:<min>
788 Fix recently introduced bug, which caused a compilation without large
789 file support, where vol_id does not recognize raid signatures at the end
792 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
793 Seems some kernel versions prevent the creation of the ieee-* links,
794 so people used the scsi-* link which disappeared now.
796 More libudev work. Almost all udevadm functionality comes from libudev
799 udevadm trigger has a new option --type, which allows to trigger events
800 for "devices", for "subsystems", or "failed" devices. The old option
801 --retry-failed" still works, but is no longer mentioned in the man page.
807 The udevadm info --device-id-of-file= output has changed to use
808 the obvious format. Possible current users should use the --export
809 option which is not affected.
811 The old udev commands symlinks to udevadm are not installed, if
812 these symlinks are used, a warning is printed.
818 Optical drive's media is no longer probed for raid signatures,
819 reading the end of the device causes some devices to malfunction.
820 Also the offset of the last session found is used now to probe
823 The volume_id library got a major version number update to 1,
824 some deprecated functions are removed.
826 A shared library "libudev" gets installed now to provide access
827 to udev device information. DeviceKit, the successor of HAL, will
828 need this library to access the udev database and search sysfs for
830 The library is currently in an experimental state, also the API is
831 expected to change, as long as the DeviceKit integration is not
836 We use ./configure now. See INSTALL for details. Current
839 "/usr" - prefix for man pages, include files
841 "" - the root filesystem, prefix for libs and binaries
845 "lib" - directory name for libraries, not a path name
846 multilib 64bit systems may use "lib64" instead of "lib"
848 compile-in verbose debug messages
850 disable all logging and compile-out all log strings
852 link against SELInux libraries, to set the expected context
855 In the default rules, the group "disk" gets permissions 0660 instead
856 of 0640. One small step closer to unify distro rules. Some day, all
857 distros hopefully end up with the same set of rules.
859 No symlinks to udevadm are installed anymore, if they are still needed,
860 they should be provided by the package.
866 Default udev rules, which are not supposed to be edited by the user, should
867 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
868 the udev package and will be replaced with an update. Udev will pick up rule
870 /lib/udev/rules.d/ - default installed rules
871 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
872 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
873 It does not matter in which directory a rule file lives, all files are sorted
876 To help creating /dev/root, we have now:
877 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
880 In case the current --device-id-of-file is already used, please switch to
881 the --export format version, it saves the output parsing and the old
882 format will be changed to use ':' as a separator, like the format in the
887 Fix cdrom_id to properly recognize blank media.
893 Tape drive id-data is queried from /dev/bsg/* instead of the tape
894 nodes. This avoids rewinding tapes on open().
900 The symlinks udevcontrol and udevtrigger are no longer installed by
903 The scsi_id program does not depend on sysfs anymore. It can speak
904 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
905 data, which should solve some old problems with tape devices, where
906 we better do not open all tape device nodes to identify the device.
912 The cdrom_id program is replaced by an advanced version, which can
913 detect most common device types, and also properties of the inserted
914 media. This is part of moving some basic functionality from HAL into
915 udev (and the kernel).
921 The last WAIT_FOR_SYSFS rule is removed from the default rules.
923 The symlinks to udevadm for the debugging tools: udevmonitor and
924 udevtest are no longer created.
926 The symlinks to the udevadm man page for the old tool names are
929 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
930 should be prefixed with '@' to indicate that the path is not a
941 Udevstart is removed from the tree, it did not get installed for
942 a long time now, and is long replaced by trigger and settle.
948 All udev tools are merged into a single binary called udevadm.
949 The old names of the tools are built-in commands in udevadm now.
950 Symlinks to udevadm, with the names of the old tools, provide
951 the same functionality as the standalone tools. There is also
952 only a single udevadm.8 man page left for all tools.
954 Tools like mkinitramfs should be checked, if they need to include
955 udevadm in the list of files.
965 The etc/udev/rules.d/ directory now contains a default set of basic
966 udev rules. This initial version is the result of a rules file merge
967 of Fedora and openSUSE. For these both distros only a few specific
968 rules are left in their own file, named after the distro. Rules which
969 are optionally installed, because they are only valid for a specific
970 architecture, or rules for subsystems which are not always used are
971 in etc/udev/packages/.
977 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
978 actions by dynamically created rules.
980 SYMLINK=="<value>" matches agains the entries in the list of
981 currently defined symlinks. The links are not created in the
982 filesystem at that point in time, but the values can be matched.
984 RUN{ignore_error}+="<program>" will ignore any exit code from the
985 program and not record as a failed event.
991 Final merge of patches/features from the Ubuntu package.
997 Control characters in filesystem label strings are no longer silenty
998 removed, but hex-encoded, to be able to uniquely identify the device
999 by its symlink in /dev/disk/by-label/.
1000 If libvolume_id is used by mount(8), LABEL= will work as expected,
1001 if slashes or other characters are used in the label string.
1003 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
1004 can be specified now. The TEST key accepts an optional mode mask
1005 TEST{0100}=="<is executable file>".
1007 Scsi_id now supports a mode without expecting scsi-specific sysfs
1008 entries to allow the extraction of cciss-device persistent properties.
1014 In the future, we may see uuid's which are just simple character
1015 strings (see the DDF Raid Specification). For that reason vol_id now
1016 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
1017 the creation of symlinks, the *_SAFE values ensure, that no control
1018 or whitespace characters are used in the filename.
1020 Possible users of libvolume_id, please use the volume_id_get_* functions.
1021 The public struct will go away in a future release of the library.
1027 Removal of useless extras/eventrecorder.sh.
1037 The directory multiplexer for dev.d/ and hotplug.d are finally removed
1038 from the udev package.
1044 Symlinks can have priorities now, the priority is assigned to the device
1045 and specified with OPTIONS="link_priority=100". Devices with higher
1046 priorities overwrite the symlinks of devices with lower priorities.
1047 If the device that currently owns the link, goes away, the symlink
1048 will be removed, and recreated, pointing to the next device with the
1049 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
1050 more reliable, if multiple devices contain the same metadata and overwrite
1053 The dasd_id program is removed from the udev tree, and dasdinfo, with the
1054 needed rules, are part of the s390-tools now.
1056 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
1057 we may get the scsi sysfs mess fixed some day, and this will only catch
1058 the devices we are looking for.
1060 USB serial numbers for storage devices have the target:lun now appended,
1061 to make it possibble to distinguish broken multi-lun devices with all
1062 the same SCSI identifiers.
1064 Note: The extra "run_directory" which searches and executes stuff in
1065 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
1066 with the next release. Make sure, that you don't use it anymore, or
1067 provides your own implementation of that inefficient stuff.
1068 We are tired of reports about a "slow udev", because these directories
1069 contain stuff, that runs with _every_ event, instead of using rules,
1070 that run programs only for the matching events.
1080 DRIVER== will match only for devices that actually have a real
1081 driver. DRIVERS== must be used, if parent devices should be
1082 included in the match.
1084 Libvolume_id's "linux_raid" detection needed another fix.
1092 Add additional check to volume_id detection of via_raid, cause
1093 some company decided to put a matching pattern all over the empty
1094 storage area of their music players.
1098 Fix path_id for SAS devices.
1102 The udev daemon can be started with --debug-trace now, which will
1103 execute all events serialized to get a chance to catch a possible
1104 action that crashes the box.
1106 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1107 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1108 are excluded from the warning. Referencing parent attributes directly
1109 may break when something in the kernel driver model changes. Udev will
1110 just find the attribute by walking up the parent chain.
1112 Udevtrigger now sorts the list of devices depending on the device
1113 dependency, so a "usb" device is triggered after the parent "pci"
1118 Revert persistent-storage ata-serial '_' '-' replacement.
1124 Udevtrigger can now filter the list of devices to be triggered. Matches
1125 for subsystems or sysfs attributes can be specified.
1127 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1128 zero-sized files to avoid pointing to /sys and confuse broken tools which
1129 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1132 The rules and scripts to create udev rules for persistent network
1133 devices and optical drives are in the extras/rules_generator directory
1134 now. If you use something similar, please consider replacing your own
1135 version with this, to share the support effort. The rule_generator
1136 installs its own rules into /etc/udev/rules.d.
1138 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1139 the rule_generator depends on cdrom_id to be called in an earlier rule.
1145 Renaming of some key names (the old names still work):
1146 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1147 (The behavior of the key DRIVER will change soon in one of the next
1148 releases, to match only the event device, please switch to DRIVERS
1149 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1151 With the new key names, we have a more consistent and simpler scheme.
1152 We can match the properties of the event device only, with: KERNEL,
1153 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1154 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1155 longer mentioned in the man page and should be switched in the rule
1158 ATTR{file}="value" can be used now, to write to a sysfs file of the
1159 event device. Instead of:
1160 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1162 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1164 All the PHYSDEV* keys are deprecated and will be removed from a
1166 PHYDEVPATH - is the path of a parent device and should not be
1168 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1169 matched with SUBSYSTEMS==
1170 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1171 Newer kernels will have DRIVER in the environment,
1172 for older kernels udev puts in. Class device will
1173 no longer carry this property of a parent and
1174 DRIVERS== can be used to match such a parent value.
1175 Note that ENV{DRIVER} is only available for a few bus devices, where
1176 the driver is already bound at device event time. On coldplug, the
1177 events for a lot devices are already bound to a driver, and they will have
1178 that value set. But on hotplug, at the time the kernel creates the device,
1179 it can't know what driver may claim the device after that, therefore
1180 in most cases it will be empty.
1182 Failed events should now be re-triggered with:
1183 udevtrigger --retry-failed.
1184 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1185 files private to the udev tools. We may need to switch the current symlink
1186 target, cause some obviously broken tools try to scan all files in /dev
1187 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1188 million times. This takes ages on slow boxes.
1190 The udevinfo attribute walk (-a) now works with giving a device node
1191 name (-n) instead of a devpath (-p). The query now always works, also when
1192 no database file was created by udev.
1194 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1195 getpwnam() and getgrnam() now. One of the next releases will depend on
1196 fnmatch() and may use getopt_long().
1200 Bugfixes and small improvements.
1204 Fix path_id for recent kernels.
1210 Added support for swapping network interface names, by temporarily
1211 renaming the device and wait for the target name to become free.
1215 The built-in MODALIAS key and substitution is removed.
1219 The binary firmware helper is replaced by the usual simple
1220 shell script. Udevsend is removed from the tree.
1228 Some more keys require the correct use of '==' and '=' depending
1229 on the kind of operation beeing an assignment or a match. Rules
1230 with invalid operations are skipped and logged to syslog. Please
1231 test with udevtest if the parsing of your rules throws errors and
1232 fix possibly broken rules.
1236 Provide "udevsettle" to wait for all current udev events to finish.
1237 It also watches the current kernel netlink queue by comparing the
1238 even sequence number to make sure that there are no current pending
1239 events that have not already arrived in the daemon.
1243 Fix rule to skip persistent rules for removable IDE devices, which
1244 also skipped optical IDE drives.
1246 All *_id program are installed in /lib/udev/ by default now.
1248 No binary is stripped anymore as this should be done in the
1249 packaging process and not at build time.
1251 libvolume_id is provided as a shared library now and vol_id is
1252 linked against it. Also one of the next HAL versions will require
1253 this library, and the HAL build process will also require the
1254 header file to be installed. The copy of the same code in HAL will
1255 be removed to have only a single copy left on the system.
1259 Add persistent links for SCSI tapes. The rules file is renamed
1260 to 60-persistent-storage.rules.
1262 Create persistent path for usb devices. Can be used for all sorts
1263 of devices that can't be distinguished by other properties like
1264 multiple identical keyboards and mice connected to the same box.
1266 Provide "udevtrigger" program to request events on coldplug. The
1267 shell script is much too slow with thousends of devices.
1271 Fix persistent disk rules to exclude removable IDE drives.
1273 Warn if %e, $modalias or MODALIAS is used.
1277 Fix queue export, which wasn't correct for subsequent add/remove
1278 events for the same device.
1282 Fix cramfs detection on big endian.
1284 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1289 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1290 attributes were only checked at the parent device that matched the
1291 by BUS requested subsystem. Fix it to also look at the device we
1292 received the event for.
1294 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1299 Fix a bug where NAME="" would prevent RUN from beeing executed.
1301 RUN="/bin/program" does not longer automatically add the subsystem
1302 as the first parameter. This is from the days of /sbin/hotplug
1303 which is dead now and it's just confusing to need to add a space at
1304 the end of the program name to prevent this.
1305 If you use rules that need the subsystem as the first parameter,
1306 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1307 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1311 The udev man page has moved to udev(7) as it does not describe a command
1312 anymore. The programs udev, udevstart and udevsend are no longer installed
1313 by default and must be copied manually, if they should be installed or
1314 included in a package.
1316 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1317 the ignore rule was applied.
1319 More preparation for future sysfs changes. usb_id and scsi_id no longer
1320 depend on a magic order of devices in the /devices chain. Specific devices
1321 should be requested by their subsytem.
1323 This will always find the scsi parent device without depending on a specific
1325 dev = sysfs_device_get(devpath);
1326 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1328 The "device" link in the current sysfs layout will be automatically
1329 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1330 parent in the devpath. If a device is requested by it's symlink, like all
1331 class devices in the new sysfs layout will look like, it gets automatically
1332 resolved and substituted with the real devpath and not the symlink path.
1335 A similar logic must be applied to _all_ sysfs users, including
1336 scripts, that search along parent devices in sysfs. The explicit use of
1337 the "device" link must be avoided. With the future sysfs layout all
1338 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1339 back to the "class" or the "bus". The layout of the parent devices in
1340 /devices is not necessarily expected to be stable across kernel releases and
1341 searching for parents by their subsystem should make sysfs users tolerant
1342 for changed parent chains.
1346 Prepare udev to work with the experimental kernel patch, that moves
1347 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1349 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1350 moving the class devices to /sys/devices.
1352 Thanks again to Marco for help finding a hopefully nice compromise
1353 to make %b simpler and working again.
1357 Complete removal of libsysfs, replaced by simple helper functions
1358 which are much simpler and a bit faster. The udev daemon operatesentirely
1359 on event parameters and does not use sysfs for simple rules anymore.
1360 Please report any new bugs/problems, that may be caused by this big
1361 change. They will be fixed immediately.
1363 The enumeration format character '%e' is deprecated and will be
1364 removed sometimes from a future udev version. It never worked correctly
1365 outside of udevstart, so we can't use it with the new parallel
1366 coldplug. A simple enumeration is as useless as the devfs naming
1367 scheme, just get rid of both if you still use it.
1369 MODALIAS and $modalias is not needed and will be removed from one of
1370 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1371 the sysfs "modalias" value.
1373 Thanks a lot to Marco for all his help on finding and fixing bugs.
1377 Let scsi_id request libata drive serial numbers from page 0x80.
1379 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1380 added /dev/disk/by-name/* for device mapper device names.
1382 Removed %e from the man page. It never worked reliably outside
1383 of udevstart and udevstart is no longer recommended to use.
1387 Symlinks are now exported to the event environment. Hopefully it's no
1388 longer needed to run udevinfo from an event process, like it was
1389 mentioned on the hotplug list:
1390 UDEV [1134776873.702967] add@/block/sdb
1393 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1397 Fix a problem if udevsend is used as the hotplug handler and tries to use
1398 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1399 and this kind of problems will hopefully go away soon.
1403 All built-in logic to work around bad sysfs timing is removed with this
1404 version. The need to wait for sysfs files is almost fixed with a kernel
1405 version that doesn't work with this udev version anyway. Until we fix
1406 the timing of the "bus" link creation, the former integrated logic should
1407 be emulated by a rule placed before all other rules:
1408 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1410 The option "udev_db" does no longer exist. All udev state will be in
1411 /$udev_root/.udev/ now, there is no longer an option to set this
1413 If the init script or something else used this value, just depend on
1414 this hardcoded path. But remember _all_content_ of this directory is
1415 still private to udev and can change at any time.
1417 Default location for rule sripts and helper programs is now: /lib/udev/.
1418 Everything that is not useful on the commandline should go into this
1419 directory. Some of the helpers in the extras folder are installed there
1420 now. The rules need to be changed, to find the helpers there.
1422 Also /lib/udev/devices is recommended as a directory where packages or
1423 the user can place real device nodes, which get copied over to /dev at
1424 every boot. This should replace the various solutions with custom config
1427 Udevsend does no longer start the udev daemon. This must be done with
1428 the init script that prepares /dev on tmpfs and creates the initial nodes,
1429 before starting the daemon.
1433 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1436 The copy of klibc is removed. A systemwide installed version of klibc
1437 should be used to build a klibc udev now.
1441 NAME="" will not create any nodes, but execute RUN keys. To completely
1442 ignore an event the OPTION "ignore_device" should be used.
1444 After removal of the reorder queue, events with a TIMEOUT can be executed
1445 without any queuing now.
1449 Fixed bug in udevd, if inotify is not available. We depend on netlink
1450 uevents now, kernels without that event source will not work with that
1451 version of udev anymore.
1455 The rule parsing happens now in the daemon once at startup, all udev
1456 event processes inherit the already parsed rules from the daemon.
1457 It is shipped with SUSE10.0 and reduces heavily the system load at
1458 startup. The option to save precompiled rules and let the udev process
1459 pick the them up is removed, as it's no longer needed.
1461 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1462 device. Libsysfs is changed to "translate" the requested link into the
1463 real device path, as it would happen with the hotplug event. Otherwise
1464 device removal and the udev database will not work.
1466 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1469 A few improvements for vol_id, the filesytem probing code.
1473 Fix a stupid typo in extras/run_directory for "make install".
1475 scsi_id creates the temporary devnode now in /dev for usage with a
1476 non-writable /tmp directory.
1478 The uevent kernel socket buffer can carry app. 50.000 events now,
1479 let's see who can break this again. :)
1481 The upcoming kernel will have a new input driver core integration.
1482 Some class devices are now symlinks to the real device. libsysfs
1483 needs a fix for this to work correctly. Udevstart of older udev
1484 versions will _not_ create these devices!
1488 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1493 A bunch of mostly trivial bugfixes. From now on no node name or
1494 symlink name can contain any character than plain whitelisted ascii
1495 characters or validated utf8 byte-streams. This is needed for the
1496 /dev/disk/by-label/* links, because we import untrusted data and
1497 export it to the filesystem.
1501 More bugfixes. If udevd was started from the kernel, we don't
1502 have stdin/stdout/stderr, which broke the forked tools in some
1507 Bugfix. udevstart event ordering was broken for a long time.
1508 The new run_program() uncovered it, because /dev/null was not
1509 available while we try to run external programs.
1510 Now udevstart should create it before we run anything.
1514 Minor bugfixes and some distro rules updates. If you don't have the
1515 persistent disk rules in /dev/disk/by-*/* on your distro, just
1516 grab it from here. :)
1520 We can use socket communication now to pass events from udev to
1522 RUN+="socket:/org/freedesktop/hal/udev_event"
1523 will pass the whole udev event to the HAL daemon without the need
1524 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1528 Mostly bugfixes and see ChangeLog.
1530 The test for the existence of an environment value should be
1532 ENV{KEY}=="*" to ENV{KEY}=="?*"
1533 because "*" will not fail anymore, if the key does not exist or
1538 Bugfixes and a few tweaks described in the ChangeLog.
1542 Mostly a Bugfix release.
1544 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1545 timing with custom rules.
1549 We changed the internal rule storage format. Our large rule files took
1550 2 MB of RAM, with the change we are down to 99kB.
1552 If the device-node has been created with default name and no symlink or
1553 options are to remenber, it is not longer stored in the udevdb. HAL will
1554 need to be updated to work correctly with that change.
1556 To overrride optimization flags, OPTFLAGS may be used now.
1564 Major changes happened with this release. The goal is to take over the
1565 complete kernel-event handling and provide a more efficient way to dispatch
1566 kernel events. Replacing most of the current shell script logic and the
1567 kernel forked helper with a netlink-daemon and a rule-based event handling.
1569 o udevd listens to netlink events now. The first valid netlink event
1570 will make udevd ignore any message from udevsend that contains a
1571 SEQNUM, to avoid duplicate events. The forked events can be disabled
1573 echo "" > /proc/sys/kernel/hotplug
1574 For full support, the broken input-subsytem needs to be fixed, not to
1575 bypass the driver core.
1577 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1578 removed from udev itself and must be emulated by calling small
1579 helper binaries provided in the extras folder:
1580 make EXTRAS=extras/run_directory/
1581 will build udev_run_devd and udev_run_hotplugd, which can be called
1582 from a rule if needed:
1583 RUN+="/sbin/udev_run_hotplugd"
1584 The recommended way to handle this is to convert all the calls from
1585 the directories to explicit udev rules and get completely rid of the
1586 multiplexing. (To catch a ttyUSB event, you now no longer need to
1587 fork and exit 300 tty script instances you are not interested in, it
1588 is just one rule that matches exactly the device.)
1590 o udev handles now _all_ events not just events for class and block
1591 devices, this way it is possible to control the complete event
1592 behavior with udev rules. Especially useful for rules like:
1593 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1595 o As used in the modalias rule, udev supports now textual
1596 substitution placeholder along with the usual format chars. This
1597 needs to be documented, for now it's only visible in udev_rules_parse.c.
1599 o The rule keys support now more operations. This is documented in the
1600 man page. It is possible to add values to list-keys like the SYMLINK
1601 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1602 Also "final"-assignments are supported by using KEY:="value", which will
1603 prevent changing the key by any later rule.
1605 o kernel 2.6.12 has the "detached_state" attribute removed from
1606 sysfs, which was used to recognize sysfs population. We switched that
1607 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1608 Running this udev version on older kernels may cause a short delay for
1611 o To provide infrastructure for persistent device naming, the id programs:
1612 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1613 to export the probed data in environment key format:
1614 pim:~ # /sbin/ata_id --export /dev/hda
1615 ID_MODEL=HTS726060M9AT00
1616 ID_SERIAL=MRH401M4G6UM9B
1617 ID_REVISION=MH4OA6BA
1619 The following rules:
1620 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1621 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1624 kay@pim:~> tree /dev/disk
1627 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1628 | `-- IBM-Memory_Key -> ../../sda
1630 | |-- swap -> ../../hda1
1631 | |-- date -> ../../sda1
1632 | `-- home -> ../../hda3
1634 |-- 2E08712B0870F2E7 -> ../../hda3
1635 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1636 |-- E845-7A89 -> ../../sda1
1637 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1639 The IMPORT= operation will import these keys in the environment and make
1640 it available for later PROGRAM= and RUN= executed programs. The keys are
1641 also stored in the udevdb and can be queried from there with one of the
1644 o A few binaries are silently added to the repository, which can be used
1645 to replay kernel events from initramfs instead of using coldplug. udevd
1646 can be instructed now to queue-up events while the stored events from
1647 initramfs are filled into the udevd-queue. This code is still under
1648 development and there is no documentation now besides the code itself.
1649 The additional binaries get compiled, but are not installed by default.
1651 o There is also a temporary fix for a performance problem where too many
1652 events happen in parallel and every event needs to parse the rules.
1653 udev can now read precompiled rules stored on disk. This is likely to be
1654 replaced by a more elegant solution in a future udev version.
1658 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1659 Fix for libsysfs not to expect this file was added.
1663 All rules are applied now, but only the first matching rule with a NAME-key
1664 will be applied. All later rules with NAME-key are completely ignored. This
1665 way system supplied symlinks or permissions gets applied to user-defined
1669 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1670 to some rules, to keep the old behavior.
1672 The rules are read on "remove"-events too. That makes is possible to match
1673 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1674 instruct udev to ignore an event (OPTIONS="ignore_device").
1675 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1677 The new RUN-key supports rule-based execution of programs after device-node
1678 handling. This is meant as a general replacement for the dev.d/-directories
1679 to give fine grained control over the execution of programs.
1681 The %s{}-sysfs format char replacement values are searched at any of the
1682 devices in the device chain now, not only at the class-device.
1684 We support log priority levels now. The value udev_log in udev.conf is used
1685 to determine what is printed to syslog. This makes it possible to
1686 run a version with compiled-in debug messages in a production environment
1687 which is sometimes needed to find a bug.
1688 It is still possible to supress the inclusion of _any_ syslog usage with
1689 USE_LOG=false to create the smallest possible binaries if needed.
1690 The configured udev_log value can be overridden with the environment variable
1695 Possible use of a system-wide klibc:
1696 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1697 will link against an external klibc and our own version will be ignored.
1701 We support an unlimited count of symlinks now.
1703 If USE_STATIC=true is passed to a glibc build, we link statically and use
1704 a built-in userdb parser to resolve user and group names.
1706 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1707 we walk up the chain of physical devices to find a match.
1709 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1710 easy to skip certain attribute matches without composing rules with weird
1711 character class negations like:
1712 KERNEL="[!s][!c][!d]*"
1713 this can now be replaced with:
1715 The current simple '=' is still supported, and should work as it does today,
1716 but existing rules should be converted if possible, to be better readable.
1718 We have new ENV{}== key now, to match against a maximum of 5 environment
1721 udevstart is its own binary again, because we don't need co carry this araound
1722 with every forked event.
~ianmdlvl / elogind.git / blob