3 Rules files in /etc/udev/rules.s/ with the same name as rules files in
4 /run/udev/rules.d/ now always have precedence. The stack of files is now:
5 /usr/lib (package), /run (runtime, auto-generated), /etc (admin), while
6 the later ones override the earlier ones. In other words: the admin has
9 USB auto-suspend is now enabled by default for some built-in USB HID
12 /dev/disk/by-path/ links are no longer created for ATA devices behind
13 an 'ATA transport class', the logic to extract predictable numbers does
14 not exist in the kernel at this moment.
16 /dev/disk/by-id/scsi-* compatibility links are no longer created for
17 ATA devices, they have their own ata-* prefix.
19 The s390 rule to set mode == 0666 for /dev/z90crypt is is removed from
20 the udev tree and will be part of s390utils (or alternatively could be
21 done by the kernel driver itself).
23 The udev-acl tool is no longer provided, it will be part of a future
24 ConsoleKit release. On systemd systems, advanced ConsoleKit and udev-acl
25 functionality are provided by systemd.
29 Require kmod version 5.
31 Provide /dev/cdrom symlink for /dev/sr0.
35 Fix for ID_PART_ENTRY_* property names, added by the blkid built-in. The
36 fix is needed for udisk2 to operate properly.
38 Fix for skipped rule execution when the kernel has removed the device
39 node in /dev again, before the event was even started. The fix is needed
40 to run device-mapper/LVM events properly.
42 Fix for the man page installation, which was skipped when xsltproc was not
47 Bugfix for $name resolution, which broke at least some keymap handling.
51 Bugfix for the firmware loading behavior with kernel modules which
52 try to load firmware in the module_init() path. The blocked event
53 runs into a timout now, which should allow the firmware to be loaded.
55 Bugfix for a wrong DEVNAME= export, which breaks at least the udev-acl
58 Bugfix for missing ID_ properties for GPT partitions.
60 The RUN+="socket:.." option is deprecated and should not be used. A warning
61 during rules parsing is printed now. Services which listen to udev events,
62 need to subscribe to the netlink messages with libudev and not let udev block
63 in the rules execution until the message is delivered.
67 Bugfix for rule_generator instalation.
71 The 'devtmpfs' filesystem is required now, udev will not create or delete
72 device nodes anymore, it only adjusts permissions and ownership of device
73 nodes and maintains additional symlinks.
75 A writable /run directory (ususally tmpfs) is required now for a fully
76 functional udev, there is no longer a fallback to /dev/.udev.
78 The default 'configure' install locations have changed. Packages for systems
79 with the historic / vs. /usr split need to be adapted, otherwise udev will
80 be installed in /usr and not work properly. Example configuration options
81 to install things the traditional way are in INSTALL.
83 The default install location of the 'udevadm' tool moved from 'sbin'
84 to /usr/bin. Some tools expect udevadm in 'sbin', a symlink to udevadm
85 needs to be manually created if needed, or --bindir=/sbin be specified.
87 The expected value of '--libexecdir=' has changed and must no longer contain
90 Kernel modules are now loaded directly by linking udev to 'libkmod'. The
91 'modprobe' tool is no longer executed by udev.
93 The 'blkid' tool is no longer executed from udev rules. Udev links
94 directly to libblkid now.
96 Firmware is loaded natively by udev now, the external 'firmware' binary
99 All built-in tools can be listed and tested with 'udevadm test-builtin'.
101 The 'udevadm control --reload-rules' option has been renamed to '--reload'.
102 It now also reloads the kernel module configuration.
104 The systemd socket files use PassCredentials=yes, which is available in
107 The udev build system only creates a .xz tarball now.
109 All tabs in the source code used for indentation are replaced by spaces now. :)
119 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
120 and non-dracut initramfs image generators need to change the init
121 scripts. Alternatively the udev build needs to move udevd back to
122 /sbin or create a symlink in /sbin, which is not done by default.
124 The path_id, usb_id, input_id tools are built-in commands now and
125 the stand-alone tools do not exist anymore. Static lists of file in
126 initramfs generators need to be updated. For testing, the commands
127 can still be executed standalone with 'udevadm test-builtin <cmd>'.
129 The fusectl filesystem is no longer mounted directly from udev.
130 Systemd systems will take care of mounting fusectl and configfs
131 now. Non-systemd systems need to ship their own rule if they
132 need these filesystems auto-mounted.
134 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
136 The support for 'udevadm trigger --type=failed, and the
137 RUN{fail_event_on_error} attribute was removed.
139 The udev control socket is now created in /run/udev/control
140 and no longer as an abstract namespace one.
142 The rules to create persistent network interface and cdrom link
143 rules automatically in /etc/udev/rules.d/ have been disabled by
144 default. Explicit configuration will be required for these use
145 cases, udev will no longer try to write any persistent system
146 configuration from a device hotplug path.
152 The udev-acl extra is no longer enabled by default now. To enable it,
153 --enable-udev_acl needs to be given at ./configure time. On systemd
154 systems, the udev-acl rules prevent it from running as the functionality
155 has moved to systemd.
161 Udev now enables kernel media-presence polling if available. Part
162 of udisks optical drive tray-handling moved to cdrom_id: The tray
163 is locked as soon as a media is detected to enable the receiving
164 of media-eject-request events. Media-eject-request events will
167 Libudev enumerate is now able to enumerate a subtree of a given
170 The mobile-action-modeswitch modeswitch tool was deleted. The
171 functionality is provided by usb_modeswitch now.
177 The systemd service files require systemd version 28. The systemd
178 socket activation make it possible now to start 'udevd' and 'udevadm
179 trigger' in parallel.
183 Fix bug in control message handling, which can lead to a failing
184 udevadm control --exit. Thanks to Jürg Billeter for help tracking
191 We require at least Linux kernel 2.6.32 now. Some platforms might
192 require a later kernel that supports accept4() and similar, or
193 need to backport the trivial syscall wiring to the older kernels.
195 The hid2hci tool moved to the bluez package and was removed.
197 Many of the extras can be --enable/--disabled at ./configure
198 time. The --disable-extras option was removed. Some extras have
199 been disabled by default. The current options and their defaults
200 can be checked with './configure --help'.
206 Udev logs a warning now if /run is not writable at udevd
207 startup. It will still fall back to /dev/.udev, but this is
208 now considered a bug.
210 The running udev daemon can now cleanly shut down with:
211 udevadm control --exit
213 Udev in initramfs should clean the state of the udev database
214 with: udevadm info --cleanup-db which will remove all state left
215 behind from events/rules in initramfs. If initramfs uses
216 --cleanup-db and device-mapper/LVM, the rules in initramfs need
217 to add OPTIONS+="db_persist" for all dm devices. This will
218 prevent removal of the udev database for these devices.
220 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
221 120 seconds per process. If that timeout is reached the spawned
222 process will be killed. The event timeout can be overwritten with
225 If systemd is used, udev gets now activated by netlink data.
226 Systemd will bind the netlink socket which will buffer all data.
227 If needed, such setup allows a seemless update of the udev daemon,
228 where no event can be lost during a udevd update/restart.
229 Packages need to make sure to: systemctl stop udev.socket udev.service
230 or 'mask' udev.service during the upgrade to prevent any unwanted
231 auto-spawning of udevd.
232 This version of udev conflicts with systemd version below 25. The
233 unchanged service files will not wirk correctly.
239 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
240 /run mountpoint is supposed to be a tmpfs mounted during early boot,
241 available and writable to for all tools at any time during bootup,
242 it replaces /var/run/, which should become a symlink some day.
244 If /run does not exist, or is not writable, udev will fall back using
247 On systemd systems with initramfs and LVM used, packagers must
248 make sure, that the systemd and initramfs versions match. The initramfs
249 needs to create the /run mountpoint for udev to store the data, and
250 mount this tmpfs to /run in the rootfs, so the that the udev database
251 is preserved for the udev version started in the rootfs.
253 The command 'udevadm info --convert-db' is gone. The udev daemon
254 itself, at startup, converts any old database version if necessary.
256 The systemd services files have been reorganized. The udev control
257 socket is bound by systemd and passed to the started udev daemon.
258 The udev-settle.service is no longer active by default. Services which
259 can not handle hotplug setups properly need to actively pull it in, to
260 act like a barrier. Alternatively the settle service can be unconditionally
261 'systemctl'enabled, and act like a barrier for basic.target.
263 The fstab_import callout is no longer built or installed. Udev
264 should not be used to mount, does not watch changes to fstab, and
265 should not mirror fstab values in the udev database.
271 New and updated keymaps.
277 The udev database has changed, After installation of a new udev
278 version, 'udevadm info --convert-db' should be called, to let the new
279 udev/libudev version read the already stored data.
281 udevadm now supports quoting of property values, and prefixing of
283 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
286 MY_DEVNAME='/dev/sda'
290 libudev now supports:
291 udev_device_get_is_initialized()
292 udev_enumerate_add_match_is_initialized()
293 to be able to skip devices the kernel has created , but udev has
296 libudev now supports:
297 udev_device_get_usec_since_initialized()
298 to retrieve the "age" of a udev device record.
300 GUdev supports a more generic GUdevEnumerator class, udev TAG
301 handling, device initialization and timestamp now.
303 The counterpart of /sys/dev/{char,block}/$major:$minor,
304 /dev/{char,block}/$major:$minor symlinks are now unconditionally
305 created, even when no rule files exist.
307 New and updated keymaps.
313 GUdev moved from /usr to /.
323 Persistent network naming rules are disabled inside of Qemu/KVM now.
325 New and updated keymaps.
327 Udev gets unconditionally enabled on systemd installations now. There
328 is no longer the need to to run 'systemctl enable udev.service'.
342 New and fixed keymaps.
344 Install systemd service files if applicable.
350 All distribution specific rules are removed from the udev source tree,
351 most of them are no longer needed. The Gentoo rules which allow to support
352 older kernel versions, which are not covered by the default rules anymore
353 has moved to rules/misc/30-kernel-compat.rules.
359 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
360 was removed from udevd.
362 Udevd now checks the kernel commandline for the following variables:
363 udev.log-priority=<syslog priority>
364 udev.children-max=<maximum number of workers>
365 udev.exec-delay=<seconds to delay the execution of RUN=>
366 to help debuging coldplug setups where the loading of a kernel
367 module crashes the system.
369 The subdirectory in the source tree rules/packages has been renamed to
370 rules/arch, anc contains only architecture specific rules now.
380 Now the udev daemon itself, does on startup:
381 - copy the content of /lib/udev/devices to /dev
382 - create the standard symlinks like /dev/std{in,out,err},
383 /dev/core, /dev/fd, ...
384 - use static node information provided by kernel modules
385 and creates these nodes to allow module on-demand loading
386 - possibly apply permissions to all ststic nodes from udev
387 rules which are annotated to match a static node
389 The default mode for a device node is 0600 now to match the kernel
390 created devtmpfs defaults. If GROUP= is specified and no MODE= is
391 given the default will be 0660.
397 Udev now gradually starts to pass control over the primary device nodes
398 and their names to the kernel, and will in the end only manage the
399 permissions of the node, and possibly create additional symlinks.
400 As a first step NAME="" will be ignored, and NAME= setings with names
401 other than the kernel provided name will result in a logged warning.
402 Kernels that don't provide device names, or devtmpfs is not used, will
403 still work as they did before, but it is strongly recommended to use
404 only the same names for the primary device node as the recent kernel
405 provides for all devices.
409 Fix broken firmware loader search path.
415 "udevadm trigger" defaults to "change" events now instead of "add"
416 events. The "udev boot script" might need to add "--action=add" to
417 the trigger command if not already there, in case the initial coldplug
418 events are expected as "add" events.
420 The option "all_partitons" was removed from udev. This should not be
421 needed for usual hardware. Udev can not safely make assumptions
422 about non-existing partition major/minor numbers, and therefore no
423 longer provide this unreliable and unsafe option.
425 The option "ignore_remove" was removed from udev. With devtmpfs
426 udev passed control over device nodes to the kernel. This option
427 should not be needed, or can not work as advertised. Neither
428 udev nor the kernel will remove device nodes which are copied from
429 the /lib/udev/devices/ directory.
431 All "add|change" matches are replaced by "!remove" in the rules and
432 in the udev logic. All types of events will update possible symlinks
433 and permissions, only "remove" is handled special now.
435 The modem modeswitch extra was removed and the external usb_modeswitch
436 program should be used instead.
438 New and fixed keymaps.
448 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
449 depend on the current sysfs layout and the information not available in the
450 deprecated layout. All remaining support for the deprecated sysfs layout is
455 Fix for a possible endless loop in the new input_id program.
461 The option "ignore_device" does no longer exist. There is no way to
462 ignore an event, as libudev events can not be suppressed by rules.
463 It only prevented RUN keys from being executed, which results in an
464 inconsistent behavior in current setups.
466 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
467 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
470 The support for the deprecated IDE devices has been removed from the
471 default set of rules. Distros who still care about non-libata drivers
472 need to add the rules to the compat rules file.
474 The ID_CLASS property on input devices has been replaced by the more accurate
475 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
476 determined by the new "input_id" prober now. Some devices, such as touchpads,
477 can have several classes. So if you previously had custom udev rules which e. g.
478 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
479 ENV{ID_INPUT_KEYBOARD}=="?*".
485 To support DEVPATH strings larger than the maximum file name length, the
486 private udev database format has changed. If some software still reads the
487 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
488 Please do not port anything to the new format again, everything in /dev/.udev
489 is and always was private to udev, and may and will change any time without
492 Multiple devices claiming the same names in /dev are limited to symlinks
493 only now. Mixing identical symlink names and node names is not supported.
494 This reduces the amount of data in the database significantly.
496 NAME="%k" causes a warning now. It's is and always was completely superfluous.
497 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
500 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
501 if they are not the default. To support older kernels, the NAME= rules need to
502 be added to the compat rules file.
504 Symlinks to udevadm with the old command names are no longer resolved to
505 the udevadm commands.
507 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
510 The option "last_rule" does no longer exist. Its use breaks too many
511 things which expect to be run from independent later rules, and is an idication
512 that something needs to be fixed properly instead.
514 The gudev API is no longer marked as experimental,
515 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
516 is enabled by default now. Various projects already depend on introspection
517 information to bind dynamic languages to the gudev interfaces.
523 The udevadm trigger "--retry-failed" option, which is replaced since quite
524 a while by "--type=failed" is removed.
526 The failed tracking was not working at all for a few releases. The RUN
527 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
528 default is not to track any failing RUN executions.
530 New keymaps, new modem, hid2hci updated.
534 Fix possible crash in udevd when worker processes are busy, rules are
535 changed at the same time, and workers get killed to reload the rules.
541 Properties set with ENV{.FOO}="bar" are marked private by starting the
542 name with a '.'. They will not be stored in the database, and not be
543 exported with the event.
545 Firmware files are looked up in:
546 /lib/firmware/updates/$(uname -r)
547 /lib/firmware/updates
548 /lib/firmware/$(uname -r)
552 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
553 ata_id, instead of scsi_id, is the default tool now for ATA devices.
559 The configure options have changed because another library needs to be
560 installed in a different location. Instead of exec_prefix and udev_prefix,
561 libdir, rootlibdir and libexecdir are used. The Details are explained in
564 Event processes now get re-used after they handled an event. This reduces
565 the number of forks and the pressure on the CPU significantly, because
566 cloned event processes no longer cause page faults in the main daemon.
567 After the events have settled, a few worker processes stay around for
568 future events, all others get cleaned up.
570 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
571 Also inotify support is mandatory now to run udev.
573 The format of the queue exported by the udev damon has changed. There is
574 no longer a /dev/.udev/queue/ directory. The current event queue can be
575 accessed with udevadm settle and libudedv.
577 Libudev does not have the unstable API header anymore. From now on,
578 incompatible changes will be handled by bumping the library major version.
580 To build udev from the git tree gtk-doc is needed now. The tarballs will
581 build without it and contain the pre-built documentation. An online copy
583 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
585 The tools from the udev-extras repository have been merged into the main
586 udev repository. Some of the extras have larger external dependencies, and
587 they can be disabled with the configure switch --disable-extras.
593 The program vol_id and the library libvolume_id are removed from the
594 repository. Libvolume_id is merged with libblkid from the util-linux-ng
595 package. Persistent disk links for label and uuid depend on the
596 util-linux-ng version (2.15) of blkid now. Older versions of blkid
597 can not be used with udev.
599 Libudev allows to subscribe to udev events. To prevent unwanted messages
600 to be delivered, and waking up the subscribing process, a filter can be
601 installed, to drop messages inside a kernel socket filter. The filters
602 match on the <subsytem>:<devtype> properties of the device.
603 This is part of the ongoing effort to replace HAL, and switch current
604 users over to directly use libudev.
605 Libudev is still marked as experimental, and its interface might
606 eventually change if needed, but no major changes of the currently exported
607 interface are expected anymore, and a first stable release should happen
610 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
611 is not supported since while and udevd will log an error message at
612 startup. It should still be able to boot-up, but advanced rules and system
613 services which depend on the information not available in the old sysfs
614 format will fail to work correctly.
616 DVB device naming is supplied by the kernel now. In case older kernels
617 need to be supported, the old shell script should be added to a compat
624 The processed udev events get send back to the netlink socket. Libudev
625 provides access to these events. This is work-in-progress, to replace
626 the DeviceKit daemon functionality directly with libudev. There are
627 upcoming kernel changes to allow non-root users to subcribe to these
634 "udevadm settle" now optionally accepts a range of events to wait for,
635 instead of waiting for "all" events.
641 The installed watch for block device metadata changes is now removed
642 during event hadling, because some (broken) tools may be called from udev
643 rules and (wrongly) open the device with write access. After the finished
644 event handling the watch is restored.
650 Device nodes can be watched for changes with inotify with OPTIONS="watch".
651 If closed after being opened for writing, a "change" uevent will occur.
652 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
658 The udevadm test command has no longer a --force option, nodes and symlinks
659 are always updated with a test run now.
661 The udevd daemon can be started with --resolve-names=never to avoid all user
662 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
663 lookup user and groups every time events are handled.
669 We are currently merging the Ubuntu rules in the udev default rules,
670 and get one step closer to provide a common Linux /dev setup, regarding
671 device names, symlinks, and default device permissions. On udev startup,
672 we now expect the following groups to be resolvable to their ids with
674 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
675 LDAP setups need to make sure, that these groups are always resolvable at
676 bootup, with only the rootfs mounted, and without network access available.
678 Some systems may need to add some new, currently not used groups, or need
679 to add some users to new groups, but the cost of this change is minimal,
680 compared to the pain the current, rather random, differences between the
681 various distributions cause for upstream projects and third-party vendors.
683 In general, "normal" users who log into a machine should never be a member
684 of any such group, but the device-access should be managed by dynamic ACLs,
685 which get added and removed for the specific users on login/logout and
686 session activity/inactivity. These groups are only provided for custom setups,
687 and mainly system services, to allow proper privilege separation.
688 A video-streaming daemon uid would be a member of "audio" and "video", to get
689 access to the sound and video devices, but no "normal" user should ever belong
690 to the "audio" group, because he could listen to the built-in microphone with
691 any ssh-session established from the other side of the world.
693 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
694 which do not depend on the kernel device name. As usual, unique
695 devices - only a single one per product connected, or a real
696 USB serial number in the device - are always found with the same
697 name in the by-id/ directory.
698 Completely identical devices may overwrite their names in by-id/
699 and can only be found reliably in the by-path/ directory. Devices
700 specified by by-path/ must not change their connection, like the
701 USB port number they are plugged in, to keep their name.
703 To support some advanced features, Linux 2.6.22 is the oldest supported
704 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
705 supported. Older kernels should still work, and devices nodes should be
706 reliably created, but some rules and libudev will not work correctly because
707 the old kernels do not provide the expected information or interfaces.
713 Fix for a possible segfault while swapping network interface names in udev
720 The group "video" is part of the default rules now.
724 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
725 block devices in some cases. No common distro uses this option anymore,
726 and we do not get enough testing for this and recent udev versions. If
727 this option is not needed to run some old distro with a new kernel,
728 it should be disabled in the kernel config.
730 Bugfix for the $links substitution variable, which may crash if no links
731 are created. This should not happen in usual setups because we always
732 create /dev/{block,char}/ links.
734 The strings of the parsed rules, which are kept in memory, no longer
735 contain duplicate entries, or duplicate tails of strings. This, and the
736 new rules parsing/matching code reduces the total in-memory size of
737 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
740 The export of DEVTYPE=disk/partition got removed from the default
741 rules. This value is available from the kernel. The pnp shell script
742 modprobe hack is removed from the default rules. ACPI devices have _proper_
743 modalias support and take care of the same functionality.
744 Installations which support old kernels, but install current default
745 udev rules may want to add that to the compat rules file.
747 Libvolume_id now always probes for all known filesystems, and does not
748 stop at the first match. Some filesystems are marked as "exclusive probe",
749 and if any other filesytem type matches at the same time, libvolume_id
750 will, by default, not return any probing result. This is intended to prevent
751 mis-detection with conflicting left-over signatures found from earlier
752 file system formats. That way, we no longer depend on the probe-order
753 in case of multiple competing signatures. In some setups the kernel allows
754 to mount a volume with just the old filesystem signature still in place.
755 This may damage the new filesystem and cause data-loss, just by mounting
756 it. Because volume_id can not decide which one the correct signature is,
757 the wrong signatures need to be removed manually from the volume, or the
758 volume needs to be reformatted, to enable filesystem detection and possible
763 Fix segfault if compiled without optimization and dbg() does not get
764 compiled out and uses variables which are not available.
768 Bugfixes. (And maybe new bugs. :))
770 The rule matching engine got converted from a rule list to a token
771 array which reduced the in-memory rules representation of a full
772 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
773 Limits like 5 ENV and ATTR matches, and one single instance for most
774 other keys per rule are gone.
776 The NAME assignment is no longer special cased. If later rules assign
777 a NAME value again, the former value will be overwritten. As usual
778 for most other keys, the NAME value can be protected by doing a final
779 assignment with NAME:="<value>".
781 All udev code now uses libudev, which is also exported. The library
782 is still under development, marked as experimental, and its interface
783 may change as long as the DeviceKit integration is not finished.
785 Many thanks to Alan Jenkins for his continuous help, and finding and
786 optimizing some of the computing expensive parts.
792 Kernel devices and device nodes are connected now by reverse indizes in
793 /sys and /dev. A device number retrieved by a stat() or similar, the
794 kernel device directory can be found by looking up:
795 /sys/dev/{block,char}/<maj>:<min>
796 and the device node of the same device by looking up:
797 /dev/{block,char}/<maj>:<min>
801 Fix recently introduced bug, which caused a compilation without large
802 file support, where vol_id does not recognize raid signatures at the end
805 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
806 Seems some kernel versions prevent the creation of the ieee-* links,
807 so people used the scsi-* link which disappeared now.
809 More libudev work. Almost all udevadm functionality comes from libudev
812 udevadm trigger has a new option --type, which allows to trigger events
813 for "devices", for "subsystems", or "failed" devices. The old option
814 --retry-failed" still works, but is no longer mentioned in the man page.
820 The udevadm info --device-id-of-file= output has changed to use
821 the obvious format. Possible current users should use the --export
822 option which is not affected.
824 The old udev commands symlinks to udevadm are not installed, if
825 these symlinks are used, a warning is printed.
831 Optical drive's media is no longer probed for raid signatures,
832 reading the end of the device causes some devices to malfunction.
833 Also the offset of the last session found is used now to probe
836 The volume_id library got a major version number update to 1,
837 some deprecated functions are removed.
839 A shared library "libudev" gets installed now to provide access
840 to udev device information. DeviceKit, the successor of HAL, will
841 need this library to access the udev database and search sysfs for
843 The library is currently in an experimental state, also the API is
844 expected to change, as long as the DeviceKit integration is not
849 We use ./configure now. See INSTALL for details. Current
852 "/usr" - prefix for man pages, include files
854 "" - the root filesystem, prefix for libs and binaries
858 "lib" - directory name for libraries, not a path name
859 multilib 64bit systems may use "lib64" instead of "lib"
861 compile-in verbose debug messages
863 disable all logging and compile-out all log strings
865 link against SELInux libraries, to set the expected context
868 In the default rules, the group "disk" gets permissions 0660 instead
869 of 0640. One small step closer to unify distro rules. Some day, all
870 distros hopefully end up with the same set of rules.
872 No symlinks to udevadm are installed anymore, if they are still needed,
873 they should be provided by the package.
879 Default udev rules, which are not supposed to be edited by the user, should
880 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
881 the udev package and will be replaced with an update. Udev will pick up rule
883 /lib/udev/rules.d/ - default installed rules
884 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
885 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
886 It does not matter in which directory a rule file lives, all files are sorted
889 To help creating /dev/root, we have now:
890 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
893 In case the current --device-id-of-file is already used, please switch to
894 the --export format version, it saves the output parsing and the old
895 format will be changed to use ':' as a separator, like the format in the
900 Fix cdrom_id to properly recognize blank media.
906 Tape drive id-data is queried from /dev/bsg/* instead of the tape
907 nodes. This avoids rewinding tapes on open().
913 The symlinks udevcontrol and udevtrigger are no longer installed by
916 The scsi_id program does not depend on sysfs anymore. It can speak
917 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
918 data, which should solve some old problems with tape devices, where
919 we better do not open all tape device nodes to identify the device.
925 The cdrom_id program is replaced by an advanced version, which can
926 detect most common device types, and also properties of the inserted
927 media. This is part of moving some basic functionality from HAL into
928 udev (and the kernel).
934 The last WAIT_FOR_SYSFS rule is removed from the default rules.
936 The symlinks to udevadm for the debugging tools: udevmonitor and
937 udevtest are no longer created.
939 The symlinks to the udevadm man page for the old tool names are
942 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
943 should be prefixed with '@' to indicate that the path is not a
954 Udevstart is removed from the tree, it did not get installed for
955 a long time now, and is long replaced by trigger and settle.
961 All udev tools are merged into a single binary called udevadm.
962 The old names of the tools are built-in commands in udevadm now.
963 Symlinks to udevadm, with the names of the old tools, provide
964 the same functionality as the standalone tools. There is also
965 only a single udevadm.8 man page left for all tools.
967 Tools like mkinitramfs should be checked, if they need to include
968 udevadm in the list of files.
978 The etc/udev/rules.d/ directory now contains a default set of basic
979 udev rules. This initial version is the result of a rules file merge
980 of Fedora and openSUSE. For these both distros only a few specific
981 rules are left in their own file, named after the distro. Rules which
982 are optionally installed, because they are only valid for a specific
983 architecture, or rules for subsystems which are not always used are
984 in etc/udev/packages/.
990 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
991 actions by dynamically created rules.
993 SYMLINK=="<value>" matches agains the entries in the list of
994 currently defined symlinks. The links are not created in the
995 filesystem at that point in time, but the values can be matched.
997 RUN{ignore_error}+="<program>" will ignore any exit code from the
998 program and not record as a failed event.
1004 Final merge of patches/features from the Ubuntu package.
1010 Control characters in filesystem label strings are no longer silenty
1011 removed, but hex-encoded, to be able to uniquely identify the device
1012 by its symlink in /dev/disk/by-label/.
1013 If libvolume_id is used by mount(8), LABEL= will work as expected,
1014 if slashes or other characters are used in the label string.
1016 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
1017 can be specified now. The TEST key accepts an optional mode mask
1018 TEST{0100}=="<is executable file>".
1020 Scsi_id now supports a mode without expecting scsi-specific sysfs
1021 entries to allow the extraction of cciss-device persistent properties.
1027 In the future, we may see uuid's which are just simple character
1028 strings (see the DDF Raid Specification). For that reason vol_id now
1029 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
1030 the creation of symlinks, the *_SAFE values ensure, that no control
1031 or whitespace characters are used in the filename.
1033 Possible users of libvolume_id, please use the volume_id_get_* functions.
1034 The public struct will go away in a future release of the library.
1040 Removal of useless extras/eventrecorder.sh.
1050 The directory multiplexer for dev.d/ and hotplug.d are finally removed
1051 from the udev package.
1057 Symlinks can have priorities now, the priority is assigned to the device
1058 and specified with OPTIONS="link_priority=100". Devices with higher
1059 priorities overwrite the symlinks of devices with lower priorities.
1060 If the device that currently owns the link, goes away, the symlink
1061 will be removed, and recreated, pointing to the next device with the
1062 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
1063 more reliable, if multiple devices contain the same metadata and overwrite
1066 The dasd_id program is removed from the udev tree, and dasdinfo, with the
1067 needed rules, are part of the s390-tools now.
1069 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
1070 we may get the scsi sysfs mess fixed some day, and this will only catch
1071 the devices we are looking for.
1073 USB serial numbers for storage devices have the target:lun now appended,
1074 to make it possibble to distinguish broken multi-lun devices with all
1075 the same SCSI identifiers.
1077 Note: The extra "run_directory" which searches and executes stuff in
1078 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
1079 with the next release. Make sure, that you don't use it anymore, or
1080 provides your own implementation of that inefficient stuff.
1081 We are tired of reports about a "slow udev", because these directories
1082 contain stuff, that runs with _every_ event, instead of using rules,
1083 that run programs only for the matching events.
1093 DRIVER== will match only for devices that actually have a real
1094 driver. DRIVERS== must be used, if parent devices should be
1095 included in the match.
1097 Libvolume_id's "linux_raid" detection needed another fix.
1105 Add additional check to volume_id detection of via_raid, cause
1106 some company decided to put a matching pattern all over the empty
1107 storage area of their music players.
1111 Fix path_id for SAS devices.
1115 The udev daemon can be started with --debug-trace now, which will
1116 execute all events serialized to get a chance to catch a possible
1117 action that crashes the box.
1119 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1120 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1121 are excluded from the warning. Referencing parent attributes directly
1122 may break when something in the kernel driver model changes. Udev will
1123 just find the attribute by walking up the parent chain.
1125 Udevtrigger now sorts the list of devices depending on the device
1126 dependency, so a "usb" device is triggered after the parent "pci"
1131 Revert persistent-storage ata-serial '_' '-' replacement.
1137 Udevtrigger can now filter the list of devices to be triggered. Matches
1138 for subsystems or sysfs attributes can be specified.
1140 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1141 zero-sized files to avoid pointing to /sys and confuse broken tools which
1142 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1145 The rules and scripts to create udev rules for persistent network
1146 devices and optical drives are in the extras/rules_generator directory
1147 now. If you use something similar, please consider replacing your own
1148 version with this, to share the support effort. The rule_generator
1149 installs its own rules into /etc/udev/rules.d.
1151 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1152 the rule_generator depends on cdrom_id to be called in an earlier rule.
1158 Renaming of some key names (the old names still work):
1159 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1160 (The behavior of the key DRIVER will change soon in one of the next
1161 releases, to match only the event device, please switch to DRIVERS
1162 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1164 With the new key names, we have a more consistent and simpler scheme.
1165 We can match the properties of the event device only, with: KERNEL,
1166 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1167 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1168 longer mentioned in the man page and should be switched in the rule
1171 ATTR{file}="value" can be used now, to write to a sysfs file of the
1172 event device. Instead of:
1173 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1175 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1177 All the PHYSDEV* keys are deprecated and will be removed from a
1179 PHYDEVPATH - is the path of a parent device and should not be
1181 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1182 matched with SUBSYSTEMS==
1183 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1184 Newer kernels will have DRIVER in the environment,
1185 for older kernels udev puts in. Class device will
1186 no longer carry this property of a parent and
1187 DRIVERS== can be used to match such a parent value.
1188 Note that ENV{DRIVER} is only available for a few bus devices, where
1189 the driver is already bound at device event time. On coldplug, the
1190 events for a lot devices are already bound to a driver, and they will have
1191 that value set. But on hotplug, at the time the kernel creates the device,
1192 it can't know what driver may claim the device after that, therefore
1193 in most cases it will be empty.
1195 Failed events should now be re-triggered with:
1196 udevtrigger --retry-failed.
1197 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1198 files private to the udev tools. We may need to switch the current symlink
1199 target, cause some obviously broken tools try to scan all files in /dev
1200 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1201 million times. This takes ages on slow boxes.
1203 The udevinfo attribute walk (-a) now works with giving a device node
1204 name (-n) instead of a devpath (-p). The query now always works, also when
1205 no database file was created by udev.
1207 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1208 getpwnam() and getgrnam() now. One of the next releases will depend on
1209 fnmatch() and may use getopt_long().
1213 Bugfixes and small improvements.
1217 Fix path_id for recent kernels.
1223 Added support for swapping network interface names, by temporarily
1224 renaming the device and wait for the target name to become free.
1228 The built-in MODALIAS key and substitution is removed.
1232 The binary firmware helper is replaced by the usual simple
1233 shell script. Udevsend is removed from the tree.
1241 Some more keys require the correct use of '==' and '=' depending
1242 on the kind of operation beeing an assignment or a match. Rules
1243 with invalid operations are skipped and logged to syslog. Please
1244 test with udevtest if the parsing of your rules throws errors and
1245 fix possibly broken rules.
1249 Provide "udevsettle" to wait for all current udev events to finish.
1250 It also watches the current kernel netlink queue by comparing the
1251 even sequence number to make sure that there are no current pending
1252 events that have not already arrived in the daemon.
1256 Fix rule to skip persistent rules for removable IDE devices, which
1257 also skipped optical IDE drives.
1259 All *_id program are installed in /lib/udev/ by default now.
1261 No binary is stripped anymore as this should be done in the
1262 packaging process and not at build time.
1264 libvolume_id is provided as a shared library now and vol_id is
1265 linked against it. Also one of the next HAL versions will require
1266 this library, and the HAL build process will also require the
1267 header file to be installed. The copy of the same code in HAL will
1268 be removed to have only a single copy left on the system.
1272 Add persistent links for SCSI tapes. The rules file is renamed
1273 to 60-persistent-storage.rules.
1275 Create persistent path for usb devices. Can be used for all sorts
1276 of devices that can't be distinguished by other properties like
1277 multiple identical keyboards and mice connected to the same box.
1279 Provide "udevtrigger" program to request events on coldplug. The
1280 shell script is much too slow with thousends of devices.
1284 Fix persistent disk rules to exclude removable IDE drives.
1286 Warn if %e, $modalias or MODALIAS is used.
1290 Fix queue export, which wasn't correct for subsequent add/remove
1291 events for the same device.
1295 Fix cramfs detection on big endian.
1297 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1302 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1303 attributes were only checked at the parent device that matched the
1304 by BUS requested subsystem. Fix it to also look at the device we
1305 received the event for.
1307 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1312 Fix a bug where NAME="" would prevent RUN from beeing executed.
1314 RUN="/bin/program" does not longer automatically add the subsystem
1315 as the first parameter. This is from the days of /sbin/hotplug
1316 which is dead now and it's just confusing to need to add a space at
1317 the end of the program name to prevent this.
1318 If you use rules that need the subsystem as the first parameter,
1319 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1320 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1324 The udev man page has moved to udev(7) as it does not describe a command
1325 anymore. The programs udev, udevstart and udevsend are no longer installed
1326 by default and must be copied manually, if they should be installed or
1327 included in a package.
1329 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1330 the ignore rule was applied.
1332 More preparation for future sysfs changes. usb_id and scsi_id no longer
1333 depend on a magic order of devices in the /devices chain. Specific devices
1334 should be requested by their subsytem.
1336 This will always find the scsi parent device without depending on a specific
1338 dev = sysfs_device_get(devpath);
1339 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1341 The "device" link in the current sysfs layout will be automatically
1342 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1343 parent in the devpath. If a device is requested by it's symlink, like all
1344 class devices in the new sysfs layout will look like, it gets automatically
1345 resolved and substituted with the real devpath and not the symlink path.
1348 A similar logic must be applied to _all_ sysfs users, including
1349 scripts, that search along parent devices in sysfs. The explicit use of
1350 the "device" link must be avoided. With the future sysfs layout all
1351 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1352 back to the "class" or the "bus". The layout of the parent devices in
1353 /devices is not necessarily expected to be stable across kernel releases and
1354 searching for parents by their subsystem should make sysfs users tolerant
1355 for changed parent chains.
1359 Prepare udev to work with the experimental kernel patch, that moves
1360 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1362 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1363 moving the class devices to /sys/devices.
1365 Thanks again to Marco for help finding a hopefully nice compromise
1366 to make %b simpler and working again.
1370 Complete removal of libsysfs, replaced by simple helper functions
1371 which are much simpler and a bit faster. The udev daemon operatesentirely
1372 on event parameters and does not use sysfs for simple rules anymore.
1373 Please report any new bugs/problems, that may be caused by this big
1374 change. They will be fixed immediately.
1376 The enumeration format character '%e' is deprecated and will be
1377 removed sometimes from a future udev version. It never worked correctly
1378 outside of udevstart, so we can't use it with the new parallel
1379 coldplug. A simple enumeration is as useless as the devfs naming
1380 scheme, just get rid of both if you still use it.
1382 MODALIAS and $modalias is not needed and will be removed from one of
1383 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1384 the sysfs "modalias" value.
1386 Thanks a lot to Marco for all his help on finding and fixing bugs.
1390 Let scsi_id request libata drive serial numbers from page 0x80.
1392 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1393 added /dev/disk/by-name/* for device mapper device names.
1395 Removed %e from the man page. It never worked reliably outside
1396 of udevstart and udevstart is no longer recommended to use.
1400 Symlinks are now exported to the event environment. Hopefully it's no
1401 longer needed to run udevinfo from an event process, like it was
1402 mentioned on the hotplug list:
1403 UDEV [1134776873.702967] add@/block/sdb
1406 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1410 Fix a problem if udevsend is used as the hotplug handler and tries to use
1411 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1412 and this kind of problems will hopefully go away soon.
1416 All built-in logic to work around bad sysfs timing is removed with this
1417 version. The need to wait for sysfs files is almost fixed with a kernel
1418 version that doesn't work with this udev version anyway. Until we fix
1419 the timing of the "bus" link creation, the former integrated logic should
1420 be emulated by a rule placed before all other rules:
1421 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1423 The option "udev_db" does no longer exist. All udev state will be in
1424 /$udev_root/.udev/ now, there is no longer an option to set this
1426 If the init script or something else used this value, just depend on
1427 this hardcoded path. But remember _all_content_ of this directory is
1428 still private to udev and can change at any time.
1430 Default location for rule sripts and helper programs is now: /lib/udev/.
1431 Everything that is not useful on the commandline should go into this
1432 directory. Some of the helpers in the extras folder are installed there
1433 now. The rules need to be changed, to find the helpers there.
1435 Also /lib/udev/devices is recommended as a directory where packages or
1436 the user can place real device nodes, which get copied over to /dev at
1437 every boot. This should replace the various solutions with custom config
1440 Udevsend does no longer start the udev daemon. This must be done with
1441 the init script that prepares /dev on tmpfs and creates the initial nodes,
1442 before starting the daemon.
1446 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1449 The copy of klibc is removed. A systemwide installed version of klibc
1450 should be used to build a klibc udev now.
1454 NAME="" will not create any nodes, but execute RUN keys. To completely
1455 ignore an event the OPTION "ignore_device" should be used.
1457 After removal of the reorder queue, events with a TIMEOUT can be executed
1458 without any queuing now.
1462 Fixed bug in udevd, if inotify is not available. We depend on netlink
1463 uevents now, kernels without that event source will not work with that
1464 version of udev anymore.
1468 The rule parsing happens now in the daemon once at startup, all udev
1469 event processes inherit the already parsed rules from the daemon.
1470 It is shipped with SUSE10.0 and reduces heavily the system load at
1471 startup. The option to save precompiled rules and let the udev process
1472 pick the them up is removed, as it's no longer needed.
1474 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1475 device. Libsysfs is changed to "translate" the requested link into the
1476 real device path, as it would happen with the hotplug event. Otherwise
1477 device removal and the udev database will not work.
1479 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1482 A few improvements for vol_id, the filesytem probing code.
1486 Fix a stupid typo in extras/run_directory for "make install".
1488 scsi_id creates the temporary devnode now in /dev for usage with a
1489 non-writable /tmp directory.
1491 The uevent kernel socket buffer can carry app. 50.000 events now,
1492 let's see who can break this again. :)
1494 The upcoming kernel will have a new input driver core integration.
1495 Some class devices are now symlinks to the real device. libsysfs
1496 needs a fix for this to work correctly. Udevstart of older udev
1497 versions will _not_ create these devices!
1501 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1506 A bunch of mostly trivial bugfixes. From now on no node name or
1507 symlink name can contain any character than plain whitelisted ascii
1508 characters or validated utf8 byte-streams. This is needed for the
1509 /dev/disk/by-label/* links, because we import untrusted data and
1510 export it to the filesystem.
1514 More bugfixes. If udevd was started from the kernel, we don't
1515 have stdin/stdout/stderr, which broke the forked tools in some
1520 Bugfix. udevstart event ordering was broken for a long time.
1521 The new run_program() uncovered it, because /dev/null was not
1522 available while we try to run external programs.
1523 Now udevstart should create it before we run anything.
1527 Minor bugfixes and some distro rules updates. If you don't have the
1528 persistent disk rules in /dev/disk/by-*/* on your distro, just
1529 grab it from here. :)
1533 We can use socket communication now to pass events from udev to
1535 RUN+="socket:/org/freedesktop/hal/udev_event"
1536 will pass the whole udev event to the HAL daemon without the need
1537 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1541 Mostly bugfixes and see ChangeLog.
1543 The test for the existence of an environment value should be
1545 ENV{KEY}=="*" to ENV{KEY}=="?*"
1546 because "*" will not fail anymore, if the key does not exist or
1551 Bugfixes and a few tweaks described in the ChangeLog.
1555 Mostly a Bugfix release.
1557 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1558 timing with custom rules.
1562 We changed the internal rule storage format. Our large rule files took
1563 2 MB of RAM, with the change we are down to 99kB.
1565 If the device-node has been created with default name and no symlink or
1566 options are to remenber, it is not longer stored in the udevdb. HAL will
1567 need to be updated to work correctly with that change.
1569 To overrride optimization flags, OPTFLAGS may be used now.
1577 Major changes happened with this release. The goal is to take over the
1578 complete kernel-event handling and provide a more efficient way to dispatch
1579 kernel events. Replacing most of the current shell script logic and the
1580 kernel forked helper with a netlink-daemon and a rule-based event handling.
1582 o udevd listens to netlink events now. The first valid netlink event
1583 will make udevd ignore any message from udevsend that contains a
1584 SEQNUM, to avoid duplicate events. The forked events can be disabled
1586 echo "" > /proc/sys/kernel/hotplug
1587 For full support, the broken input-subsytem needs to be fixed, not to
1588 bypass the driver core.
1590 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1591 removed from udev itself and must be emulated by calling small
1592 helper binaries provided in the extras folder:
1593 make EXTRAS=extras/run_directory/
1594 will build udev_run_devd and udev_run_hotplugd, which can be called
1595 from a rule if needed:
1596 RUN+="/sbin/udev_run_hotplugd"
1597 The recommended way to handle this is to convert all the calls from
1598 the directories to explicit udev rules and get completely rid of the
1599 multiplexing. (To catch a ttyUSB event, you now no longer need to
1600 fork and exit 300 tty script instances you are not interested in, it
1601 is just one rule that matches exactly the device.)
1603 o udev handles now _all_ events not just events for class and block
1604 devices, this way it is possible to control the complete event
1605 behavior with udev rules. Especially useful for rules like:
1606 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1608 o As used in the modalias rule, udev supports now textual
1609 substitution placeholder along with the usual format chars. This
1610 needs to be documented, for now it's only visible in udev_rules_parse.c.
1612 o The rule keys support now more operations. This is documented in the
1613 man page. It is possible to add values to list-keys like the SYMLINK
1614 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1615 Also "final"-assignments are supported by using KEY:="value", which will
1616 prevent changing the key by any later rule.
1618 o kernel 2.6.12 has the "detached_state" attribute removed from
1619 sysfs, which was used to recognize sysfs population. We switched that
1620 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1621 Running this udev version on older kernels may cause a short delay for
1624 o To provide infrastructure for persistent device naming, the id programs:
1625 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1626 to export the probed data in environment key format:
1627 pim:~ # /sbin/ata_id --export /dev/hda
1628 ID_MODEL=HTS726060M9AT00
1629 ID_SERIAL=MRH401M4G6UM9B
1630 ID_REVISION=MH4OA6BA
1632 The following rules:
1633 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1634 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1637 kay@pim:~> tree /dev/disk
1640 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1641 | `-- IBM-Memory_Key -> ../../sda
1643 | |-- swap -> ../../hda1
1644 | |-- date -> ../../sda1
1645 | `-- home -> ../../hda3
1647 |-- 2E08712B0870F2E7 -> ../../hda3
1648 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1649 |-- E845-7A89 -> ../../sda1
1650 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1652 The IMPORT= operation will import these keys in the environment and make
1653 it available for later PROGRAM= and RUN= executed programs. The keys are
1654 also stored in the udevdb and can be queried from there with one of the
1657 o A few binaries are silently added to the repository, which can be used
1658 to replay kernel events from initramfs instead of using coldplug. udevd
1659 can be instructed now to queue-up events while the stored events from
1660 initramfs are filled into the udevd-queue. This code is still under
1661 development and there is no documentation now besides the code itself.
1662 The additional binaries get compiled, but are not installed by default.
1664 o There is also a temporary fix for a performance problem where too many
1665 events happen in parallel and every event needs to parse the rules.
1666 udev can now read precompiled rules stored on disk. This is likely to be
1667 replaced by a more elegant solution in a future udev version.
1671 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1672 Fix for libsysfs not to expect this file was added.
1676 All rules are applied now, but only the first matching rule with a NAME-key
1677 will be applied. All later rules with NAME-key are completely ignored. This
1678 way system supplied symlinks or permissions gets applied to user-defined
1682 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1683 to some rules, to keep the old behavior.
1685 The rules are read on "remove"-events too. That makes is possible to match
1686 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1687 instruct udev to ignore an event (OPTIONS="ignore_device").
1688 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1690 The new RUN-key supports rule-based execution of programs after device-node
1691 handling. This is meant as a general replacement for the dev.d/-directories
1692 to give fine grained control over the execution of programs.
1694 The %s{}-sysfs format char replacement values are searched at any of the
1695 devices in the device chain now, not only at the class-device.
1697 We support log priority levels now. The value udev_log in udev.conf is used
1698 to determine what is printed to syslog. This makes it possible to
1699 run a version with compiled-in debug messages in a production environment
1700 which is sometimes needed to find a bug.
1701 It is still possible to supress the inclusion of _any_ syslog usage with
1702 USE_LOG=false to create the smallest possible binaries if needed.
1703 The configured udev_log value can be overridden with the environment variable
1708 Possible use of a system-wide klibc:
1709 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1710 will link against an external klibc and our own version will be ignored.
1714 We support an unlimited count of symlinks now.
1716 If USE_STATIC=true is passed to a glibc build, we link statically and use
1717 a built-in userdb parser to resolve user and group names.
1719 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1720 we walk up the chain of physical devices to find a match.
1722 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1723 easy to skip certain attribute matches without composing rules with weird
1724 character class negations like:
1725 KERNEL="[!s][!c][!d]*"
1726 this can now be replaced with:
1728 The current simple '=' is still supported, and should work as it does today,
1729 but existing rules should be converted if possible, to be better readable.
1731 We have new ENV{}== key now, to match against a maximum of 5 environment
1734 udevstart is its own binary again, because we don't need co carry this araound
1735 with every forked event.