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.
10 Require kmod version 5.
12 Provide /dev/cdrom symlink for /dev/sr0.
16 Fix for ID_PART_ENTRY_* property names, added by the blkid built-in. The
17 fix is needed for udisk2 to operate properly.
19 Fix for skipped rule execution when the kernel has removed the device
20 node in /dev again, before the event was even started. The fix is needed
21 to run device-mapper/LVM events properly.
23 Fix for the man page installation, which was skipped when xsltproc was not
28 Bugfix for $name resolution, which broke at least some keymap handling.
32 Bugfix for the firmware loading behavior with kernel modules which
33 try to load firmware in the module_init() path. The blocked event
34 runs into a timout now, which should allow the firmware to be loaded.
36 Bugfix for a wrong DEVNAME= export, which breaks at least the udev-acl
39 Bugfix for missing ID_ properties for GPT partitions.
41 The RUN+="socket:.." option is deprecated and should not be used. A warning
42 during rules parsing is printed now. Services which listen to udev events,
43 need to subscribe to the netlink messages with libudev and not let udev block
44 in the rules execution until the message is delivered.
48 Bugfix for rule_generator instalation.
52 The 'devtmpfs' filesystem is required now, udev will not create or delete
53 device nodes anymore, it only adjusts permissions and ownership of device
54 nodes and maintains additional symlinks.
56 A writable /run directory (ususally tmpfs) is required now for a fully
57 functional udev, there is no longer a fallback to /dev/.udev.
59 The default 'configure' install locations have changed. Packages for systems
60 with the historic / vs. /usr split need to be adapted, otherwise udev will
61 be installed in /usr and not work properly. Example configuration options
62 to install things the traditional way are in INSTALL.
64 The default install location of the 'udevadm' tool moved from 'sbin'
65 to /usr/bin. Some tools expect udevadm in 'sbin', a symlink to udevadm
66 needs to be manually created if needed, or --bindir=/sbin be specified.
68 The expected value of '--libexecdir=' has changed and must no longer contain
71 Kernel modules are now loaded directly by linking udev to 'libkmod'. The
72 'modprobe' tool is no longer executed by udev.
74 The 'blkid' tool is no longer executed from udev rules. Udev links
75 directly to libblkid now.
77 Firmware is loaded natively by udev now, the external 'firmware' binary
80 All built-in tools can be listed and tested with 'udevadm test-builtin'.
82 The 'udevadm control --reload-rules' option has been renamed to '--reload'.
83 It now also reloads the kernel module configuration.
85 The systemd socket files use PassCredentials=yes, which is available in
88 The udev build system only creates a .xz tarball now.
90 All tabs in the source code used for indentation are replaced by spaces now. :)
100 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
101 and non-dracut initramfs image generators need to change the init
102 scripts. Alternatively the udev build needs to move udevd back to
103 /sbin or create a symlink in /sbin, which is not done by default.
105 The path_id, usb_id, input_id tools are built-in commands now and
106 the stand-alone tools do not exist anymore. Static lists of file in
107 initramfs generators need to be updated. For testing, the commands
108 can still be executed standalone with 'udevadm test-builtin <cmd>'.
110 The fusectl filesystem is no longer mounted directly from udev.
111 Systemd systems will take care of mounting fusectl and configfs
112 now. Non-systemd systems need to ship their own rule if they
113 need these filesystems auto-mounted.
115 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
117 The support for 'udevadm trigger --type=failed, and the
118 RUN{fail_event_on_error} attribute was removed.
120 The udev control socket is now created in /run/udev/control
121 and no longer as an abstract namespace one.
123 The rules to create persistent network interface and cdrom link
124 rules automatically in /etc/udev/rules.d/ have been disabled by
125 default. Explicit configuration will be required for these use
126 cases, udev will no longer try to write any persistent system
127 configuration from a device hotplug path.
133 The udev-acl extra is no longer enabled by default now. To enable it,
134 --enable-udev_acl needs to be given at ./configure time. On systemd
135 systems, the udev-acl rules prevent it from running as the functionality
136 has moved to systemd.
142 Udev now enables kernel media-presence polling if available. Part
143 of udisks optical drive tray-handling moved to cdrom_id: The tray
144 is locked as soon as a media is detected to enable the receiving
145 of media-eject-request events. Media-eject-request events will
148 Libudev enumerate is now able to enumerate a subtree of a given
151 The mobile-action-modeswitch modeswitch tool was deleted. The
152 functionality is provided by usb_modeswitch now.
158 The systemd service files require systemd version 28. The systemd
159 socket activation make it possible now to start 'udevd' and 'udevadm
160 trigger' in parallel.
164 Fix bug in control message handling, which can lead to a failing
165 udevadm control --exit. Thanks to Jürg Billeter for help tracking
172 We require at least Linux kernel 2.6.32 now. Some platforms might
173 require a later kernel that supports accept4() and similar, or
174 need to backport the trivial syscall wiring to the older kernels.
176 The hid2hci tool moved to the bluez package and was removed.
178 Many of the extras can be --enable/--disabled at ./configure
179 time. The --disable-extras option was removed. Some extras have
180 been disabled by default. The current options and their defaults
181 can be checked with './configure --help'.
187 Udev logs a warning now if /run is not writable at udevd
188 startup. It will still fall back to /dev/.udev, but this is
189 now considered a bug.
191 The running udev daemon can now cleanly shut down with:
192 udevadm control --exit
194 Udev in initramfs should clean the state of the udev database
195 with: udevadm info --cleanup-db which will remove all state left
196 behind from events/rules in initramfs. If initramfs uses
197 --cleanup-db and device-mapper/LVM, the rules in initramfs need
198 to add OPTIONS+="db_persist" for all dm devices. This will
199 prevent removal of the udev database for these devices.
201 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
202 120 seconds per process. If that timeout is reached the spawned
203 process will be killed. The event timeout can be overwritten with
206 If systemd is used, udev gets now activated by netlink data.
207 Systemd will bind the netlink socket which will buffer all data.
208 If needed, such setup allows a seemless update of the udev daemon,
209 where no event can be lost during a udevd update/restart.
210 Packages need to make sure to: systemctl stop udev.socket udev.service
211 or 'mask' udev.service during the upgrade to prevent any unwanted
212 auto-spawning of udevd.
213 This version of udev conflicts with systemd version below 25. The
214 unchanged service files will not wirk correctly.
220 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
221 /run mountpoint is supposed to be a tmpfs mounted during early boot,
222 available and writable to for all tools at any time during bootup,
223 it replaces /var/run/, which should become a symlink some day.
225 If /run does not exist, or is not writable, udev will fall back using
228 On systemd systems with initramfs and LVM used, packagers must
229 make sure, that the systemd and initramfs versions match. The initramfs
230 needs to create the /run mountpoint for udev to store the data, and
231 mount this tmpfs to /run in the rootfs, so the that the udev database
232 is preserved for the udev version started in the rootfs.
234 The command 'udevadm info --convert-db' is gone. The udev daemon
235 itself, at startup, converts any old database version if necessary.
237 The systemd services files have been reorganized. The udev control
238 socket is bound by systemd and passed to the started udev daemon.
239 The udev-settle.service is no longer active by default. Services which
240 can not handle hotplug setups properly need to actively pull it in, to
241 act like a barrier. Alternatively the settle service can be unconditionally
242 'systemctl'enabled, and act like a barrier for basic.target.
244 The fstab_import callout is no longer built or installed. Udev
245 should not be used to mount, does not watch changes to fstab, and
246 should not mirror fstab values in the udev database.
252 New and updated keymaps.
258 The udev database has changed, After installation of a new udev
259 version, 'udevadm info --convert-db' should be called, to let the new
260 udev/libudev version read the already stored data.
262 udevadm now supports quoting of property values, and prefixing of
264 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
267 MY_DEVNAME='/dev/sda'
271 libudev now supports:
272 udev_device_get_is_initialized()
273 udev_enumerate_add_match_is_initialized()
274 to be able to skip devices the kernel has created , but udev has
277 libudev now supports:
278 udev_device_get_usec_since_initialized()
279 to retrieve the "age" of a udev device record.
281 GUdev supports a more generic GUdevEnumerator class, udev TAG
282 handling, device initialization and timestamp now.
284 The counterpart of /sys/dev/{char,block}/$major:$minor,
285 /dev/{char,block}/$major:$minor symlinks are now unconditionally
286 created, even when no rule files exist.
288 New and updated keymaps.
294 GUdev moved from /usr to /.
304 Persistent network naming rules are disabled inside of Qemu/KVM now.
306 New and updated keymaps.
308 Udev gets unconditionally enabled on systemd installations now. There
309 is no longer the need to to run 'systemctl enable udev.service'.
323 New and fixed keymaps.
325 Install systemd service files if applicable.
331 All distribution specific rules are removed from the udev source tree,
332 most of them are no longer needed. The Gentoo rules which allow to support
333 older kernel versions, which are not covered by the default rules anymore
334 has moved to rules/misc/30-kernel-compat.rules.
340 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
341 was removed from udevd.
343 Udevd now checks the kernel commandline for the following variables:
344 udev.log-priority=<syslog priority>
345 udev.children-max=<maximum number of workers>
346 udev.exec-delay=<seconds to delay the execution of RUN=>
347 to help debuging coldplug setups where the loading of a kernel
348 module crashes the system.
350 The subdirectory in the source tree rules/packages has been renamed to
351 rules/arch, anc contains only architecture specific rules now.
361 Now the udev daemon itself, does on startup:
362 - copy the content of /lib/udev/devices to /dev
363 - create the standard symlinks like /dev/std{in,out,err},
364 /dev/core, /dev/fd, ...
365 - use static node information provided by kernel modules
366 and creates these nodes to allow module on-demand loading
367 - possibly apply permissions to all ststic nodes from udev
368 rules which are annotated to match a static node
370 The default mode for a device node is 0600 now to match the kernel
371 created devtmpfs defaults. If GROUP= is specified and no MODE= is
372 given the default will be 0660.
378 Udev now gradually starts to pass control over the primary device nodes
379 and their names to the kernel, and will in the end only manage the
380 permissions of the node, and possibly create additional symlinks.
381 As a first step NAME="" will be ignored, and NAME= setings with names
382 other than the kernel provided name will result in a logged warning.
383 Kernels that don't provide device names, or devtmpfs is not used, will
384 still work as they did before, but it is strongly recommended to use
385 only the same names for the primary device node as the recent kernel
386 provides for all devices.
390 Fix broken firmware loader search path.
396 "udevadm trigger" defaults to "change" events now instead of "add"
397 events. The "udev boot script" might need to add "--action=add" to
398 the trigger command if not already there, in case the initial coldplug
399 events are expected as "add" events.
401 The option "all_partitons" was removed from udev. This should not be
402 needed for usual hardware. Udev can not safely make assumptions
403 about non-existing partition major/minor numbers, and therefore no
404 longer provide this unreliable and unsafe option.
406 The option "ignore_remove" was removed from udev. With devtmpfs
407 udev passed control over device nodes to the kernel. This option
408 should not be needed, or can not work as advertised. Neither
409 udev nor the kernel will remove device nodes which are copied from
410 the /lib/udev/devices/ directory.
412 All "add|change" matches are replaced by "!remove" in the rules and
413 in the udev logic. All types of events will update possible symlinks
414 and permissions, only "remove" is handled special now.
416 The modem modeswitch extra was removed and the external usb_modeswitch
417 program should be used instead.
419 New and fixed keymaps.
429 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
430 depend on the current sysfs layout and the information not available in the
431 deprecated layout. All remaining support for the deprecated sysfs layout is
436 Fix for a possible endless loop in the new input_id program.
442 The option "ignore_device" does no longer exist. There is no way to
443 ignore an event, as libudev events can not be suppressed by rules.
444 It only prevented RUN keys from being executed, which results in an
445 inconsistent behavior in current setups.
447 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
448 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
451 The support for the deprecated IDE devices has been removed from the
452 default set of rules. Distros who still care about non-libata drivers
453 need to add the rules to the compat rules file.
455 The ID_CLASS property on input devices has been replaced by the more accurate
456 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
457 determined by the new "input_id" prober now. Some devices, such as touchpads,
458 can have several classes. So if you previously had custom udev rules which e. g.
459 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
460 ENV{ID_INPUT_KEYBOARD}=="?*".
466 To support DEVPATH strings larger than the maximum file name length, the
467 private udev database format has changed. If some software still reads the
468 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
469 Please do not port anything to the new format again, everything in /dev/.udev
470 is and always was private to udev, and may and will change any time without
473 Multiple devices claiming the same names in /dev are limited to symlinks
474 only now. Mixing identical symlink names and node names is not supported.
475 This reduces the amount of data in the database significantly.
477 NAME="%k" causes a warning now. It's is and always was completely superfluous.
478 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
481 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
482 if they are not the default. To support older kernels, the NAME= rules need to
483 be added to the compat rules file.
485 Symlinks to udevadm with the old command names are no longer resolved to
486 the udevadm commands.
488 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
491 The option "last_rule" does no longer exist. Its use breaks too many
492 things which expect to be run from independent later rules, and is an idication
493 that something needs to be fixed properly instead.
495 The gudev API is no longer marked as experimental,
496 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
497 is enabled by default now. Various projects already depend on introspection
498 information to bind dynamic languages to the gudev interfaces.
504 The udevadm trigger "--retry-failed" option, which is replaced since quite
505 a while by "--type=failed" is removed.
507 The failed tracking was not working at all for a few releases. The RUN
508 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
509 default is not to track any failing RUN executions.
511 New keymaps, new modem, hid2hci updated.
515 Fix possible crash in udevd when worker processes are busy, rules are
516 changed at the same time, and workers get killed to reload the rules.
522 Properties set with ENV{.FOO}="bar" are marked private by starting the
523 name with a '.'. They will not be stored in the database, and not be
524 exported with the event.
526 Firmware files are looked up in:
527 /lib/firmware/updates/$(uname -r)
528 /lib/firmware/updates
529 /lib/firmware/$(uname -r)
533 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
534 ata_id, instead of scsi_id, is the default tool now for ATA devices.
540 The configure options have changed because another library needs to be
541 installed in a different location. Instead of exec_prefix and udev_prefix,
542 libdir, rootlibdir and libexecdir are used. The Details are explained in
545 Event processes now get re-used after they handled an event. This reduces
546 the number of forks and the pressure on the CPU significantly, because
547 cloned event processes no longer cause page faults in the main daemon.
548 After the events have settled, a few worker processes stay around for
549 future events, all others get cleaned up.
551 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
552 Also inotify support is mandatory now to run udev.
554 The format of the queue exported by the udev damon has changed. There is
555 no longer a /dev/.udev/queue/ directory. The current event queue can be
556 accessed with udevadm settle and libudedv.
558 Libudev does not have the unstable API header anymore. From now on,
559 incompatible changes will be handled by bumping the library major version.
561 To build udev from the git tree gtk-doc is needed now. The tarballs will
562 build without it and contain the pre-built documentation. An online copy
564 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
566 The tools from the udev-extras repository have been merged into the main
567 udev repository. Some of the extras have larger external dependencies, and
568 they can be disabled with the configure switch --disable-extras.
574 The program vol_id and the library libvolume_id are removed from the
575 repository. Libvolume_id is merged with libblkid from the util-linux-ng
576 package. Persistent disk links for label and uuid depend on the
577 util-linux-ng version (2.15) of blkid now. Older versions of blkid
578 can not be used with udev.
580 Libudev allows to subscribe to udev events. To prevent unwanted messages
581 to be delivered, and waking up the subscribing process, a filter can be
582 installed, to drop messages inside a kernel socket filter. The filters
583 match on the <subsytem>:<devtype> properties of the device.
584 This is part of the ongoing effort to replace HAL, and switch current
585 users over to directly use libudev.
586 Libudev is still marked as experimental, and its interface might
587 eventually change if needed, but no major changes of the currently exported
588 interface are expected anymore, and a first stable release should happen
591 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
592 is not supported since while and udevd will log an error message at
593 startup. It should still be able to boot-up, but advanced rules and system
594 services which depend on the information not available in the old sysfs
595 format will fail to work correctly.
597 DVB device naming is supplied by the kernel now. In case older kernels
598 need to be supported, the old shell script should be added to a compat
605 The processed udev events get send back to the netlink socket. Libudev
606 provides access to these events. This is work-in-progress, to replace
607 the DeviceKit daemon functionality directly with libudev. There are
608 upcoming kernel changes to allow non-root users to subcribe to these
615 "udevadm settle" now optionally accepts a range of events to wait for,
616 instead of waiting for "all" events.
622 The installed watch for block device metadata changes is now removed
623 during event hadling, because some (broken) tools may be called from udev
624 rules and (wrongly) open the device with write access. After the finished
625 event handling the watch is restored.
631 Device nodes can be watched for changes with inotify with OPTIONS="watch".
632 If closed after being opened for writing, a "change" uevent will occur.
633 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
639 The udevadm test command has no longer a --force option, nodes and symlinks
640 are always updated with a test run now.
642 The udevd daemon can be started with --resolve-names=never to avoid all user
643 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
644 lookup user and groups every time events are handled.
650 We are currently merging the Ubuntu rules in the udev default rules,
651 and get one step closer to provide a common Linux /dev setup, regarding
652 device names, symlinks, and default device permissions. On udev startup,
653 we now expect the following groups to be resolvable to their ids with
655 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
656 LDAP setups need to make sure, that these groups are always resolvable at
657 bootup, with only the rootfs mounted, and without network access available.
659 Some systems may need to add some new, currently not used groups, or need
660 to add some users to new groups, but the cost of this change is minimal,
661 compared to the pain the current, rather random, differences between the
662 various distributions cause for upstream projects and third-party vendors.
664 In general, "normal" users who log into a machine should never be a member
665 of any such group, but the device-access should be managed by dynamic ACLs,
666 which get added and removed for the specific users on login/logout and
667 session activity/inactivity. These groups are only provided for custom setups,
668 and mainly system services, to allow proper privilege separation.
669 A video-streaming daemon uid would be a member of "audio" and "video", to get
670 access to the sound and video devices, but no "normal" user should ever belong
671 to the "audio" group, because he could listen to the built-in microphone with
672 any ssh-session established from the other side of the world.
674 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
675 which do not depend on the kernel device name. As usual, unique
676 devices - only a single one per product connected, or a real
677 USB serial number in the device - are always found with the same
678 name in the by-id/ directory.
679 Completely identical devices may overwrite their names in by-id/
680 and can only be found reliably in the by-path/ directory. Devices
681 specified by by-path/ must not change their connection, like the
682 USB port number they are plugged in, to keep their name.
684 To support some advanced features, Linux 2.6.22 is the oldest supported
685 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
686 supported. Older kernels should still work, and devices nodes should be
687 reliably created, but some rules and libudev will not work correctly because
688 the old kernels do not provide the expected information or interfaces.
694 Fix for a possible segfault while swapping network interface names in udev
701 The group "video" is part of the default rules now.
705 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
706 block devices in some cases. No common distro uses this option anymore,
707 and we do not get enough testing for this and recent udev versions. If
708 this option is not needed to run some old distro with a new kernel,
709 it should be disabled in the kernel config.
711 Bugfix for the $links substitution variable, which may crash if no links
712 are created. This should not happen in usual setups because we always
713 create /dev/{block,char}/ links.
715 The strings of the parsed rules, which are kept in memory, no longer
716 contain duplicate entries, or duplicate tails of strings. This, and the
717 new rules parsing/matching code reduces the total in-memory size of
718 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
721 The export of DEVTYPE=disk/partition got removed from the default
722 rules. This value is available from the kernel. The pnp shell script
723 modprobe hack is removed from the default rules. ACPI devices have _proper_
724 modalias support and take care of the same functionality.
725 Installations which support old kernels, but install current default
726 udev rules may want to add that to the compat rules file.
728 Libvolume_id now always probes for all known filesystems, and does not
729 stop at the first match. Some filesystems are marked as "exclusive probe",
730 and if any other filesytem type matches at the same time, libvolume_id
731 will, by default, not return any probing result. This is intended to prevent
732 mis-detection with conflicting left-over signatures found from earlier
733 file system formats. That way, we no longer depend on the probe-order
734 in case of multiple competing signatures. In some setups the kernel allows
735 to mount a volume with just the old filesystem signature still in place.
736 This may damage the new filesystem and cause data-loss, just by mounting
737 it. Because volume_id can not decide which one the correct signature is,
738 the wrong signatures need to be removed manually from the volume, or the
739 volume needs to be reformatted, to enable filesystem detection and possible
744 Fix segfault if compiled without optimization and dbg() does not get
745 compiled out and uses variables which are not available.
749 Bugfixes. (And maybe new bugs. :))
751 The rule matching engine got converted from a rule list to a token
752 array which reduced the in-memory rules representation of a full
753 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
754 Limits like 5 ENV and ATTR matches, and one single instance for most
755 other keys per rule are gone.
757 The NAME assignment is no longer special cased. If later rules assign
758 a NAME value again, the former value will be overwritten. As usual
759 for most other keys, the NAME value can be protected by doing a final
760 assignment with NAME:="<value>".
762 All udev code now uses libudev, which is also exported. The library
763 is still under development, marked as experimental, and its interface
764 may change as long as the DeviceKit integration is not finished.
766 Many thanks to Alan Jenkins for his continuous help, and finding and
767 optimizing some of the computing expensive parts.
773 Kernel devices and device nodes are connected now by reverse indizes in
774 /sys and /dev. A device number retrieved by a stat() or similar, the
775 kernel device directory can be found by looking up:
776 /sys/dev/{block,char}/<maj>:<min>
777 and the device node of the same device by looking up:
778 /dev/{block,char}/<maj>:<min>
782 Fix recently introduced bug, which caused a compilation without large
783 file support, where vol_id does not recognize raid signatures at the end
786 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
787 Seems some kernel versions prevent the creation of the ieee-* links,
788 so people used the scsi-* link which disappeared now.
790 More libudev work. Almost all udevadm functionality comes from libudev
793 udevadm trigger has a new option --type, which allows to trigger events
794 for "devices", for "subsystems", or "failed" devices. The old option
795 --retry-failed" still works, but is no longer mentioned in the man page.
801 The udevadm info --device-id-of-file= output has changed to use
802 the obvious format. Possible current users should use the --export
803 option which is not affected.
805 The old udev commands symlinks to udevadm are not installed, if
806 these symlinks are used, a warning is printed.
812 Optical drive's media is no longer probed for raid signatures,
813 reading the end of the device causes some devices to malfunction.
814 Also the offset of the last session found is used now to probe
817 The volume_id library got a major version number update to 1,
818 some deprecated functions are removed.
820 A shared library "libudev" gets installed now to provide access
821 to udev device information. DeviceKit, the successor of HAL, will
822 need this library to access the udev database and search sysfs for
824 The library is currently in an experimental state, also the API is
825 expected to change, as long as the DeviceKit integration is not
830 We use ./configure now. See INSTALL for details. Current
833 "/usr" - prefix for man pages, include files
835 "" - the root filesystem, prefix for libs and binaries
839 "lib" - directory name for libraries, not a path name
840 multilib 64bit systems may use "lib64" instead of "lib"
842 compile-in verbose debug messages
844 disable all logging and compile-out all log strings
846 link against SELInux libraries, to set the expected context
849 In the default rules, the group "disk" gets permissions 0660 instead
850 of 0640. One small step closer to unify distro rules. Some day, all
851 distros hopefully end up with the same set of rules.
853 No symlinks to udevadm are installed anymore, if they are still needed,
854 they should be provided by the package.
860 Default udev rules, which are not supposed to be edited by the user, should
861 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
862 the udev package and will be replaced with an update. Udev will pick up rule
864 /lib/udev/rules.d/ - default installed rules
865 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
866 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
867 It does not matter in which directory a rule file lives, all files are sorted
870 To help creating /dev/root, we have now:
871 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
874 In case the current --device-id-of-file is already used, please switch to
875 the --export format version, it saves the output parsing and the old
876 format will be changed to use ':' as a separator, like the format in the
881 Fix cdrom_id to properly recognize blank media.
887 Tape drive id-data is queried from /dev/bsg/* instead of the tape
888 nodes. This avoids rewinding tapes on open().
894 The symlinks udevcontrol and udevtrigger are no longer installed by
897 The scsi_id program does not depend on sysfs anymore. It can speak
898 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
899 data, which should solve some old problems with tape devices, where
900 we better do not open all tape device nodes to identify the device.
906 The cdrom_id program is replaced by an advanced version, which can
907 detect most common device types, and also properties of the inserted
908 media. This is part of moving some basic functionality from HAL into
909 udev (and the kernel).
915 The last WAIT_FOR_SYSFS rule is removed from the default rules.
917 The symlinks to udevadm for the debugging tools: udevmonitor and
918 udevtest are no longer created.
920 The symlinks to the udevadm man page for the old tool names are
923 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
924 should be prefixed with '@' to indicate that the path is not a
935 Udevstart is removed from the tree, it did not get installed for
936 a long time now, and is long replaced by trigger and settle.
942 All udev tools are merged into a single binary called udevadm.
943 The old names of the tools are built-in commands in udevadm now.
944 Symlinks to udevadm, with the names of the old tools, provide
945 the same functionality as the standalone tools. There is also
946 only a single udevadm.8 man page left for all tools.
948 Tools like mkinitramfs should be checked, if they need to include
949 udevadm in the list of files.
959 The etc/udev/rules.d/ directory now contains a default set of basic
960 udev rules. This initial version is the result of a rules file merge
961 of Fedora and openSUSE. For these both distros only a few specific
962 rules are left in their own file, named after the distro. Rules which
963 are optionally installed, because they are only valid for a specific
964 architecture, or rules for subsystems which are not always used are
965 in etc/udev/packages/.
971 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
972 actions by dynamically created rules.
974 SYMLINK=="<value>" matches agains the entries in the list of
975 currently defined symlinks. The links are not created in the
976 filesystem at that point in time, but the values can be matched.
978 RUN{ignore_error}+="<program>" will ignore any exit code from the
979 program and not record as a failed event.
985 Final merge of patches/features from the Ubuntu package.
991 Control characters in filesystem label strings are no longer silenty
992 removed, but hex-encoded, to be able to uniquely identify the device
993 by its symlink in /dev/disk/by-label/.
994 If libvolume_id is used by mount(8), LABEL= will work as expected,
995 if slashes or other characters are used in the label string.
997 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
998 can be specified now. The TEST key accepts an optional mode mask
999 TEST{0100}=="<is executable file>".
1001 Scsi_id now supports a mode without expecting scsi-specific sysfs
1002 entries to allow the extraction of cciss-device persistent properties.
1008 In the future, we may see uuid's which are just simple character
1009 strings (see the DDF Raid Specification). For that reason vol_id now
1010 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
1011 the creation of symlinks, the *_SAFE values ensure, that no control
1012 or whitespace characters are used in the filename.
1014 Possible users of libvolume_id, please use the volume_id_get_* functions.
1015 The public struct will go away in a future release of the library.
1021 Removal of useless extras/eventrecorder.sh.
1031 The directory multiplexer for dev.d/ and hotplug.d are finally removed
1032 from the udev package.
1038 Symlinks can have priorities now, the priority is assigned to the device
1039 and specified with OPTIONS="link_priority=100". Devices with higher
1040 priorities overwrite the symlinks of devices with lower priorities.
1041 If the device that currently owns the link, goes away, the symlink
1042 will be removed, and recreated, pointing to the next device with the
1043 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
1044 more reliable, if multiple devices contain the same metadata and overwrite
1047 The dasd_id program is removed from the udev tree, and dasdinfo, with the
1048 needed rules, are part of the s390-tools now.
1050 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
1051 we may get the scsi sysfs mess fixed some day, and this will only catch
1052 the devices we are looking for.
1054 USB serial numbers for storage devices have the target:lun now appended,
1055 to make it possibble to distinguish broken multi-lun devices with all
1056 the same SCSI identifiers.
1058 Note: The extra "run_directory" which searches and executes stuff in
1059 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
1060 with the next release. Make sure, that you don't use it anymore, or
1061 provides your own implementation of that inefficient stuff.
1062 We are tired of reports about a "slow udev", because these directories
1063 contain stuff, that runs with _every_ event, instead of using rules,
1064 that run programs only for the matching events.
1074 DRIVER== will match only for devices that actually have a real
1075 driver. DRIVERS== must be used, if parent devices should be
1076 included in the match.
1078 Libvolume_id's "linux_raid" detection needed another fix.
1086 Add additional check to volume_id detection of via_raid, cause
1087 some company decided to put a matching pattern all over the empty
1088 storage area of their music players.
1092 Fix path_id for SAS devices.
1096 The udev daemon can be started with --debug-trace now, which will
1097 execute all events serialized to get a chance to catch a possible
1098 action that crashes the box.
1100 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1101 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1102 are excluded from the warning. Referencing parent attributes directly
1103 may break when something in the kernel driver model changes. Udev will
1104 just find the attribute by walking up the parent chain.
1106 Udevtrigger now sorts the list of devices depending on the device
1107 dependency, so a "usb" device is triggered after the parent "pci"
1112 Revert persistent-storage ata-serial '_' '-' replacement.
1118 Udevtrigger can now filter the list of devices to be triggered. Matches
1119 for subsystems or sysfs attributes can be specified.
1121 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1122 zero-sized files to avoid pointing to /sys and confuse broken tools which
1123 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1126 The rules and scripts to create udev rules for persistent network
1127 devices and optical drives are in the extras/rules_generator directory
1128 now. If you use something similar, please consider replacing your own
1129 version with this, to share the support effort. The rule_generator
1130 installs its own rules into /etc/udev/rules.d.
1132 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1133 the rule_generator depends on cdrom_id to be called in an earlier rule.
1139 Renaming of some key names (the old names still work):
1140 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1141 (The behavior of the key DRIVER will change soon in one of the next
1142 releases, to match only the event device, please switch to DRIVERS
1143 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1145 With the new key names, we have a more consistent and simpler scheme.
1146 We can match the properties of the event device only, with: KERNEL,
1147 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1148 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1149 longer mentioned in the man page and should be switched in the rule
1152 ATTR{file}="value" can be used now, to write to a sysfs file of the
1153 event device. Instead of:
1154 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1156 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1158 All the PHYSDEV* keys are deprecated and will be removed from a
1160 PHYDEVPATH - is the path of a parent device and should not be
1162 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1163 matched with SUBSYSTEMS==
1164 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1165 Newer kernels will have DRIVER in the environment,
1166 for older kernels udev puts in. Class device will
1167 no longer carry this property of a parent and
1168 DRIVERS== can be used to match such a parent value.
1169 Note that ENV{DRIVER} is only available for a few bus devices, where
1170 the driver is already bound at device event time. On coldplug, the
1171 events for a lot devices are already bound to a driver, and they will have
1172 that value set. But on hotplug, at the time the kernel creates the device,
1173 it can't know what driver may claim the device after that, therefore
1174 in most cases it will be empty.
1176 Failed events should now be re-triggered with:
1177 udevtrigger --retry-failed.
1178 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1179 files private to the udev tools. We may need to switch the current symlink
1180 target, cause some obviously broken tools try to scan all files in /dev
1181 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1182 million times. This takes ages on slow boxes.
1184 The udevinfo attribute walk (-a) now works with giving a device node
1185 name (-n) instead of a devpath (-p). The query now always works, also when
1186 no database file was created by udev.
1188 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1189 getpwnam() and getgrnam() now. One of the next releases will depend on
1190 fnmatch() and may use getopt_long().
1194 Bugfixes and small improvements.
1198 Fix path_id for recent kernels.
1204 Added support for swapping network interface names, by temporarily
1205 renaming the device and wait for the target name to become free.
1209 The built-in MODALIAS key and substitution is removed.
1213 The binary firmware helper is replaced by the usual simple
1214 shell script. Udevsend is removed from the tree.
1222 Some more keys require the correct use of '==' and '=' depending
1223 on the kind of operation beeing an assignment or a match. Rules
1224 with invalid operations are skipped and logged to syslog. Please
1225 test with udevtest if the parsing of your rules throws errors and
1226 fix possibly broken rules.
1230 Provide "udevsettle" to wait for all current udev events to finish.
1231 It also watches the current kernel netlink queue by comparing the
1232 even sequence number to make sure that there are no current pending
1233 events that have not already arrived in the daemon.
1237 Fix rule to skip persistent rules for removable IDE devices, which
1238 also skipped optical IDE drives.
1240 All *_id program are installed in /lib/udev/ by default now.
1242 No binary is stripped anymore as this should be done in the
1243 packaging process and not at build time.
1245 libvolume_id is provided as a shared library now and vol_id is
1246 linked against it. Also one of the next HAL versions will require
1247 this library, and the HAL build process will also require the
1248 header file to be installed. The copy of the same code in HAL will
1249 be removed to have only a single copy left on the system.
1253 Add persistent links for SCSI tapes. The rules file is renamed
1254 to 60-persistent-storage.rules.
1256 Create persistent path for usb devices. Can be used for all sorts
1257 of devices that can't be distinguished by other properties like
1258 multiple identical keyboards and mice connected to the same box.
1260 Provide "udevtrigger" program to request events on coldplug. The
1261 shell script is much too slow with thousends of devices.
1265 Fix persistent disk rules to exclude removable IDE drives.
1267 Warn if %e, $modalias or MODALIAS is used.
1271 Fix queue export, which wasn't correct for subsequent add/remove
1272 events for the same device.
1276 Fix cramfs detection on big endian.
1278 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1283 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1284 attributes were only checked at the parent device that matched the
1285 by BUS requested subsystem. Fix it to also look at the device we
1286 received the event for.
1288 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1293 Fix a bug where NAME="" would prevent RUN from beeing executed.
1295 RUN="/bin/program" does not longer automatically add the subsystem
1296 as the first parameter. This is from the days of /sbin/hotplug
1297 which is dead now and it's just confusing to need to add a space at
1298 the end of the program name to prevent this.
1299 If you use rules that need the subsystem as the first parameter,
1300 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1301 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1305 The udev man page has moved to udev(7) as it does not describe a command
1306 anymore. The programs udev, udevstart and udevsend are no longer installed
1307 by default and must be copied manually, if they should be installed or
1308 included in a package.
1310 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1311 the ignore rule was applied.
1313 More preparation for future sysfs changes. usb_id and scsi_id no longer
1314 depend on a magic order of devices in the /devices chain. Specific devices
1315 should be requested by their subsytem.
1317 This will always find the scsi parent device without depending on a specific
1319 dev = sysfs_device_get(devpath);
1320 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1322 The "device" link in the current sysfs layout will be automatically
1323 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1324 parent in the devpath. If a device is requested by it's symlink, like all
1325 class devices in the new sysfs layout will look like, it gets automatically
1326 resolved and substituted with the real devpath and not the symlink path.
1329 A similar logic must be applied to _all_ sysfs users, including
1330 scripts, that search along parent devices in sysfs. The explicit use of
1331 the "device" link must be avoided. With the future sysfs layout all
1332 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1333 back to the "class" or the "bus". The layout of the parent devices in
1334 /devices is not necessarily expected to be stable across kernel releases and
1335 searching for parents by their subsystem should make sysfs users tolerant
1336 for changed parent chains.
1340 Prepare udev to work with the experimental kernel patch, that moves
1341 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1343 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1344 moving the class devices to /sys/devices.
1346 Thanks again to Marco for help finding a hopefully nice compromise
1347 to make %b simpler and working again.
1351 Complete removal of libsysfs, replaced by simple helper functions
1352 which are much simpler and a bit faster. The udev daemon operatesentirely
1353 on event parameters and does not use sysfs for simple rules anymore.
1354 Please report any new bugs/problems, that may be caused by this big
1355 change. They will be fixed immediately.
1357 The enumeration format character '%e' is deprecated and will be
1358 removed sometimes from a future udev version. It never worked correctly
1359 outside of udevstart, so we can't use it with the new parallel
1360 coldplug. A simple enumeration is as useless as the devfs naming
1361 scheme, just get rid of both if you still use it.
1363 MODALIAS and $modalias is not needed and will be removed from one of
1364 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1365 the sysfs "modalias" value.
1367 Thanks a lot to Marco for all his help on finding and fixing bugs.
1371 Let scsi_id request libata drive serial numbers from page 0x80.
1373 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1374 added /dev/disk/by-name/* for device mapper device names.
1376 Removed %e from the man page. It never worked reliably outside
1377 of udevstart and udevstart is no longer recommended to use.
1381 Symlinks are now exported to the event environment. Hopefully it's no
1382 longer needed to run udevinfo from an event process, like it was
1383 mentioned on the hotplug list:
1384 UDEV [1134776873.702967] add@/block/sdb
1387 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1391 Fix a problem if udevsend is used as the hotplug handler and tries to use
1392 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1393 and this kind of problems will hopefully go away soon.
1397 All built-in logic to work around bad sysfs timing is removed with this
1398 version. The need to wait for sysfs files is almost fixed with a kernel
1399 version that doesn't work with this udev version anyway. Until we fix
1400 the timing of the "bus" link creation, the former integrated logic should
1401 be emulated by a rule placed before all other rules:
1402 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1404 The option "udev_db" does no longer exist. All udev state will be in
1405 /$udev_root/.udev/ now, there is no longer an option to set this
1407 If the init script or something else used this value, just depend on
1408 this hardcoded path. But remember _all_content_ of this directory is
1409 still private to udev and can change at any time.
1411 Default location for rule sripts and helper programs is now: /lib/udev/.
1412 Everything that is not useful on the commandline should go into this
1413 directory. Some of the helpers in the extras folder are installed there
1414 now. The rules need to be changed, to find the helpers there.
1416 Also /lib/udev/devices is recommended as a directory where packages or
1417 the user can place real device nodes, which get copied over to /dev at
1418 every boot. This should replace the various solutions with custom config
1421 Udevsend does no longer start the udev daemon. This must be done with
1422 the init script that prepares /dev on tmpfs and creates the initial nodes,
1423 before starting the daemon.
1427 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1430 The copy of klibc is removed. A systemwide installed version of klibc
1431 should be used to build a klibc udev now.
1435 NAME="" will not create any nodes, but execute RUN keys. To completely
1436 ignore an event the OPTION "ignore_device" should be used.
1438 After removal of the reorder queue, events with a TIMEOUT can be executed
1439 without any queuing now.
1443 Fixed bug in udevd, if inotify is not available. We depend on netlink
1444 uevents now, kernels without that event source will not work with that
1445 version of udev anymore.
1449 The rule parsing happens now in the daemon once at startup, all udev
1450 event processes inherit the already parsed rules from the daemon.
1451 It is shipped with SUSE10.0 and reduces heavily the system load at
1452 startup. The option to save precompiled rules and let the udev process
1453 pick the them up is removed, as it's no longer needed.
1455 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1456 device. Libsysfs is changed to "translate" the requested link into the
1457 real device path, as it would happen with the hotplug event. Otherwise
1458 device removal and the udev database will not work.
1460 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1463 A few improvements for vol_id, the filesytem probing code.
1467 Fix a stupid typo in extras/run_directory for "make install".
1469 scsi_id creates the temporary devnode now in /dev for usage with a
1470 non-writable /tmp directory.
1472 The uevent kernel socket buffer can carry app. 50.000 events now,
1473 let's see who can break this again. :)
1475 The upcoming kernel will have a new input driver core integration.
1476 Some class devices are now symlinks to the real device. libsysfs
1477 needs a fix for this to work correctly. Udevstart of older udev
1478 versions will _not_ create these devices!
1482 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1487 A bunch of mostly trivial bugfixes. From now on no node name or
1488 symlink name can contain any character than plain whitelisted ascii
1489 characters or validated utf8 byte-streams. This is needed for the
1490 /dev/disk/by-label/* links, because we import untrusted data and
1491 export it to the filesystem.
1495 More bugfixes. If udevd was started from the kernel, we don't
1496 have stdin/stdout/stderr, which broke the forked tools in some
1501 Bugfix. udevstart event ordering was broken for a long time.
1502 The new run_program() uncovered it, because /dev/null was not
1503 available while we try to run external programs.
1504 Now udevstart should create it before we run anything.
1508 Minor bugfixes and some distro rules updates. If you don't have the
1509 persistent disk rules in /dev/disk/by-*/* on your distro, just
1510 grab it from here. :)
1514 We can use socket communication now to pass events from udev to
1516 RUN+="socket:/org/freedesktop/hal/udev_event"
1517 will pass the whole udev event to the HAL daemon without the need
1518 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1522 Mostly bugfixes and see ChangeLog.
1524 The test for the existence of an environment value should be
1526 ENV{KEY}=="*" to ENV{KEY}=="?*"
1527 because "*" will not fail anymore, if the key does not exist or
1532 Bugfixes and a few tweaks described in the ChangeLog.
1536 Mostly a Bugfix release.
1538 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1539 timing with custom rules.
1543 We changed the internal rule storage format. Our large rule files took
1544 2 MB of RAM, with the change we are down to 99kB.
1546 If the device-node has been created with default name and no symlink or
1547 options are to remenber, it is not longer stored in the udevdb. HAL will
1548 need to be updated to work correctly with that change.
1550 To overrride optimization flags, OPTFLAGS may be used now.
1558 Major changes happened with this release. The goal is to take over the
1559 complete kernel-event handling and provide a more efficient way to dispatch
1560 kernel events. Replacing most of the current shell script logic and the
1561 kernel forked helper with a netlink-daemon and a rule-based event handling.
1563 o udevd listens to netlink events now. The first valid netlink event
1564 will make udevd ignore any message from udevsend that contains a
1565 SEQNUM, to avoid duplicate events. The forked events can be disabled
1567 echo "" > /proc/sys/kernel/hotplug
1568 For full support, the broken input-subsytem needs to be fixed, not to
1569 bypass the driver core.
1571 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1572 removed from udev itself and must be emulated by calling small
1573 helper binaries provided in the extras folder:
1574 make EXTRAS=extras/run_directory/
1575 will build udev_run_devd and udev_run_hotplugd, which can be called
1576 from a rule if needed:
1577 RUN+="/sbin/udev_run_hotplugd"
1578 The recommended way to handle this is to convert all the calls from
1579 the directories to explicit udev rules and get completely rid of the
1580 multiplexing. (To catch a ttyUSB event, you now no longer need to
1581 fork and exit 300 tty script instances you are not interested in, it
1582 is just one rule that matches exactly the device.)
1584 o udev handles now _all_ events not just events for class and block
1585 devices, this way it is possible to control the complete event
1586 behavior with udev rules. Especially useful for rules like:
1587 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1589 o As used in the modalias rule, udev supports now textual
1590 substitution placeholder along with the usual format chars. This
1591 needs to be documented, for now it's only visible in udev_rules_parse.c.
1593 o The rule keys support now more operations. This is documented in the
1594 man page. It is possible to add values to list-keys like the SYMLINK
1595 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1596 Also "final"-assignments are supported by using KEY:="value", which will
1597 prevent changing the key by any later rule.
1599 o kernel 2.6.12 has the "detached_state" attribute removed from
1600 sysfs, which was used to recognize sysfs population. We switched that
1601 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1602 Running this udev version on older kernels may cause a short delay for
1605 o To provide infrastructure for persistent device naming, the id programs:
1606 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1607 to export the probed data in environment key format:
1608 pim:~ # /sbin/ata_id --export /dev/hda
1609 ID_MODEL=HTS726060M9AT00
1610 ID_SERIAL=MRH401M4G6UM9B
1611 ID_REVISION=MH4OA6BA
1613 The following rules:
1614 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1615 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1618 kay@pim:~> tree /dev/disk
1621 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1622 | `-- IBM-Memory_Key -> ../../sda
1624 | |-- swap -> ../../hda1
1625 | |-- date -> ../../sda1
1626 | `-- home -> ../../hda3
1628 |-- 2E08712B0870F2E7 -> ../../hda3
1629 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1630 |-- E845-7A89 -> ../../sda1
1631 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1633 The IMPORT= operation will import these keys in the environment and make
1634 it available for later PROGRAM= and RUN= executed programs. The keys are
1635 also stored in the udevdb and can be queried from there with one of the
1638 o A few binaries are silently added to the repository, which can be used
1639 to replay kernel events from initramfs instead of using coldplug. udevd
1640 can be instructed now to queue-up events while the stored events from
1641 initramfs are filled into the udevd-queue. This code is still under
1642 development and there is no documentation now besides the code itself.
1643 The additional binaries get compiled, but are not installed by default.
1645 o There is also a temporary fix for a performance problem where too many
1646 events happen in parallel and every event needs to parse the rules.
1647 udev can now read precompiled rules stored on disk. This is likely to be
1648 replaced by a more elegant solution in a future udev version.
1652 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1653 Fix for libsysfs not to expect this file was added.
1657 All rules are applied now, but only the first matching rule with a NAME-key
1658 will be applied. All later rules with NAME-key are completely ignored. This
1659 way system supplied symlinks or permissions gets applied to user-defined
1663 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1664 to some rules, to keep the old behavior.
1666 The rules are read on "remove"-events too. That makes is possible to match
1667 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1668 instruct udev to ignore an event (OPTIONS="ignore_device").
1669 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1671 The new RUN-key supports rule-based execution of programs after device-node
1672 handling. This is meant as a general replacement for the dev.d/-directories
1673 to give fine grained control over the execution of programs.
1675 The %s{}-sysfs format char replacement values are searched at any of the
1676 devices in the device chain now, not only at the class-device.
1678 We support log priority levels now. The value udev_log in udev.conf is used
1679 to determine what is printed to syslog. This makes it possible to
1680 run a version with compiled-in debug messages in a production environment
1681 which is sometimes needed to find a bug.
1682 It is still possible to supress the inclusion of _any_ syslog usage with
1683 USE_LOG=false to create the smallest possible binaries if needed.
1684 The configured udev_log value can be overridden with the environment variable
1689 Possible use of a system-wide klibc:
1690 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1691 will link against an external klibc and our own version will be ignored.
1695 We support an unlimited count of symlinks now.
1697 If USE_STATIC=true is passed to a glibc build, we link statically and use
1698 a built-in userdb parser to resolve user and group names.
1700 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1701 we walk up the chain of physical devices to find a match.
1703 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1704 easy to skip certain attribute matches without composing rules with weird
1705 character class negations like:
1706 KERNEL="[!s][!c][!d]*"
1707 this can now be replaced with:
1709 The current simple '=' is still supported, and should work as it does today,
1710 but existing rules should be converted if possible, to be better readable.
1712 We have new ENV{}== key now, to match against a maximum of 5 environment
1715 udevstart is its own binary again, because we don't need co carry this araound
1716 with every forked event.