3 The default configure options have changed, packages need to be adapted
4 otherwise udev will be installed in /usr. Example configuration options
7 The default prefix moved from / to /usr to support installations without
8 the historic / vs. /usr split.
10 The default install location of the 'udevadm' tool moved from 'sbin'
11 to /usr/bin. Some tools expect udevadm in 'sbin'. A symlink to udevadm
12 needs to be manually created if needed.
14 Kernel modules are now loaded directly by linking udev to 'libkmod'.
15 The 'modprobe' tool is no longer executed by udev.
17 The 'blkid' tool is no longer executed from udev rules. Udev links
18 directly to libblkid now.
20 Firmware is loaded natively by udev now, the external 'firmware' binary
23 All built-in tools can be listed and tested with 'udevadm test-builtin'.
25 The 'udevadm control --reload-rules' option has been renamed to '--reload'.
26 It reloads the kernel module configuration.
28 The systemd socket files use PassCred=yes, which requires systemd
31 The udev build system only creates a .xz tarball now.
41 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
42 and non-dracut initramfs image generators need to change the init
43 scripts. Alternatively the udev build needs to move udevd back to
44 /sbin or create a symlink in /sbin, which is not done by default.
46 The path_id, usb_id, input_id tools are built-in commands now and
47 the stand-alone tools do not exist anymore. Static lists of file in
48 initramfs generators need to be updated. For testing, the commands
49 can still be executed standalone with 'udevadm test-builtin <cmd>'.
51 The fusectl filesystem is no longer mounted directly from udev.
52 Systemd systems will take care of mounting fusectl and configfs
53 now. Non-systemd systems need to ship their own rule if they
54 need these filesystems auto-mounted.
56 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
58 The support for 'udevadm trigger --type=failed, and the
59 RUN{fail_event_on_error} attribute was removed.
61 The udev control socket is now created in /run/udev/control
62 and no longer as an abstract namespace one.
64 The rules to create persistent network interface and cdrom link
65 rules automatically in /etc/udev/rules.d/ have been disabled by
66 default. Explicit configuration will be required for these use
67 cases, udev will no longer try to write any persistent system
68 configuration from a device hotplug path.
74 The udev-acl extra is no longer enabled by default now. To enable it,
75 --enable-udev_acl needs to be given at ./configure time. On systemd
76 systems, the udev-acl rules prevent it from running as the functionality
83 Udev now enables kernel media-presence polling if available. Part
84 of udisks optical drive tray-handling moved to cdrom_id: The tray
85 is locked as soon as a media is detected to enable the receiving
86 of media-eject-request events. Media-eject-request events will
89 Libudev enumerate is now able to enumerate a subtree of a given
92 The mobile-action-modeswitch modeswitch tool was deleted. The
93 functionality is provided by usb_modeswitch now.
99 The systemd service files require systemd version 28. The systemd
100 socket activation make it possible now to start 'udevd' and 'udevadm
101 trigger' in parallel.
105 Fix bug in control message handling, which can lead to a failing
106 udevadm control --exit. Thanks to Jürg Billeter for help tracking
113 We require at least Linux kernel 2.6.32 now. Some platforms might
114 require a later kernel that supports accept4() and similar, or
115 need to backport the trivial syscall wiring to the older kernels.
117 The hid2hci tool moved to the bluez package and was removed.
119 Many of the extras can be --enable/--disabled at ./configure
120 time. The --disable-extras option was removed. Some extras have
121 been disabled by default. The current options and their defaults
122 can be checked with './configure --help'.
128 Udev logs a warning now if /run is not writable at udevd
129 startup. It will still fall back to /dev/.udev, but this is
130 now considered a bug.
132 The running udev daemon can now cleanly shut down with:
133 udevadm control --exit
135 Udev in initramfs should clean the state of the udev database
136 with: udevadm info --cleanup-db which will remove all state left
137 behind from events/rules in initramfs. If initramfs uses
138 --cleanup-db and device-mapper/LVM, the rules in initramfs need
139 to add OPTIONS+="db_persist" for all dm devices. This will
140 prevent removal of the udev database for these devices.
142 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
143 120 seconds per process. If that timeout is reached the spawned
144 process will be killed. The event timeout can be overwritten with
147 If systemd is used, udev gets now activated by netlink data.
148 Systemd will bind the netlink socket which will buffer all data.
149 If needed, such setup allows a seemless update of the udev daemon,
150 where no event can be lost during a udevd update/restart.
151 Packages need to make sure to: systemctl stop udev.socket udev.service
152 or 'mask' udev.service during the upgrade to prevent any unwanted
153 auto-spawning of udevd.
154 This version of udev conflicts with systemd version below 25. The
155 unchanged service files will not wirk correctly.
161 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
162 /run mountpoint is supposed to be a tmpfs mounted during early boot,
163 available and writable to for all tools at any time during bootup,
164 it replaces /var/run/, which should become a symlink some day.
166 If /run does not exist, or is not writable, udev will fall back using
169 On systemd systems with initramfs and LVM used, packagers must
170 make sure, that the systemd and initramfs versions match. The initramfs
171 needs to create the /run mountpoint for udev to store the data, and
172 mount this tmpfs to /run in the rootfs, so the that the udev database
173 is preserved for the udev version started in the rootfs.
175 The command 'udevadm info --convert-db' is gone. The udev daemon
176 itself, at startup, converts any old database version if necessary.
178 The systemd services files have been reorganized. The udev control
179 socket is bound by systemd and passed to the started udev daemon.
180 The udev-settle.service is no longer active by default. Services which
181 can not handle hotplug setups properly need to actively pull it in, to
182 act like a barrier. Alternatively the settle service can be unconditionally
183 'systemctl'enabled, and act like a barrier for basic.target.
185 The fstab_import callout is no longer built or installed. Udev
186 should not be used to mount, does not watch changes to fstab, and
187 should not mirror fstab values in the udev database.
193 New and updated keymaps.
199 The udev database has changed, After installation of a new udev
200 version, 'udevadm info --convert-db' should be called, to let the new
201 udev/libudev version read the already stored data.
203 udevadm now supports quoting of property values, and prefixing of
205 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
208 MY_DEVNAME='/dev/sda'
212 libudev now supports:
213 udev_device_get_is_initialized()
214 udev_enumerate_add_match_is_initialized()
215 to be able to skip devices the kernel has created , but udev has
218 libudev now supports:
219 udev_device_get_usec_since_initialized()
220 to retrieve the "age" of a udev device record.
222 GUdev supports a more generic GUdevEnumerator class, udev TAG
223 handling, device initialization and timestamp now.
225 The counterpart of /sys/dev/{char,block}/$major:$minor,
226 /dev/{char,block}/$major:$minor symlinks are now unconditionally
227 created, even when no rule files exist.
229 New and updated keymaps.
235 GUdev moved from /usr to /.
245 Persistent network naming rules are disabled inside of Qemu/KVM now.
247 New and updated keymaps.
249 Udev gets unconditionally enabled on systemd installations now. There
250 is no longer the need to to run 'systemctl enable udev.service'.
264 New and fixed keymaps.
266 Install systemd service files if applicable.
272 All distribution specific rules are removed from the udev source tree,
273 most of them are no longer needed. The Gentoo rules which allow to support
274 older kernel versions, which are not covered by the default rules anymore
275 has moved to rules/misc/30-kernel-compat.rules.
281 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
282 was removed from udevd.
284 Udevd now checks the kernel commandline for the following variables:
285 udev.log-priority=<syslog priority>
286 udev.children-max=<maximum number of workers>
287 udev.exec-delay=<seconds to delay the execution of RUN=>
288 to help debuging coldplug setups where the loading of a kernel
289 module crashes the system.
291 The subdirectory in the source tree rules/packages has been renamed to
292 rules/arch, anc contains only architecture specific rules now.
302 Now the udev daemon itself, does on startup:
303 - copy the content of /lib/udev/devices to /dev
304 - create the standard symlinks like /dev/std{in,out,err},
305 /dev/core, /dev/fd, ...
306 - use static node information provided by kernel modules
307 and creates these nodes to allow module on-demand loading
308 - possibly apply permissions to all ststic nodes from udev
309 rules which are annotated to match a static node
311 The default mode for a device node is 0600 now to match the kernel
312 created devtmpfs defaults. If GROUP= is specified and no MODE= is
313 given the default will be 0660.
319 Udev now gradually starts to pass control over the primary device nodes
320 and their names to the kernel, and will in the end only manage the
321 permissions of the node, and possibly create additional symlinks.
322 As a first step NAME="" will be ignored, and NAME= setings with names
323 other than the kernel provided name will result in a logged warning.
324 Kernels that don't provide device names, or devtmpfs is not used, will
325 still work as they did before, but it is strongly recommended to use
326 only the same names for the primary device node as the recent kernel
327 provides for all devices.
331 Fix broken firmware loader search path.
337 "udevadm trigger" defaults to "change" events now instead of "add"
338 events. The "udev boot script" might need to add "--action=add" to
339 the trigger command if not already there, in case the initial coldplug
340 events are expected as "add" events.
342 The option "all_partitons" was removed from udev. This should not be
343 needed for usual hardware. Udev can not safely make assumptions
344 about non-existing partition major/minor numbers, and therefore no
345 longer provide this unreliable and unsafe option.
347 The option "ignore_remove" was removed from udev. With devtmpfs
348 udev passed control over device nodes to the kernel. This option
349 should not be needed, or can not work as advertised. Neither
350 udev nor the kernel will remove device nodes which are copied from
351 the /lib/udev/devices/ directory.
353 All "add|change" matches are replaced by "!remove" in the rules and
354 in the udev logic. All types of events will update possible symlinks
355 and permissions, only "remove" is handled special now.
357 The modem modeswitch extra was removed and the external usb_modeswitch
358 program should be used instead.
360 New and fixed keymaps.
370 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
371 depend on the current sysfs layout and the information not available in the
372 deprecated layout. All remaining support for the deprecated sysfs layout is
377 Fix for a possible endless loop in the new input_id program.
383 The option "ignore_device" does no longer exist. There is no way to
384 ignore an event, as libudev events can not be suppressed by rules.
385 It only prevented RUN keys from being executed, which results in an
386 inconsistent behavior in current setups.
388 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
389 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
392 The support for the deprecated IDE devices has been removed from the
393 default set of rules. Distros who still care about non-libata drivers
394 need to add the rules to the compat rules file.
396 The ID_CLASS property on input devices has been replaced by the more accurate
397 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
398 determined by the new "input_id" prober now. Some devices, such as touchpads,
399 can have several classes. So if you previously had custom udev rules which e. g.
400 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
401 ENV{ID_INPUT_KEYBOARD}=="?*".
407 To support DEVPATH strings larger than the maximum file name length, the
408 private udev database format has changed. If some software still reads the
409 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
410 Please do not port anything to the new format again, everything in /dev/.udev
411 is and always was private to udev, and may and will change any time without
414 Multiple devices claiming the same names in /dev are limited to symlinks
415 only now. Mixing identical symlink names and node names is not supported.
416 This reduces the amount of data in the database significantly.
418 NAME="%k" causes a warning now. It's is and always was completely superfluous.
419 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
422 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
423 if they are not the default. To support older kernels, the NAME= rules need to
424 be added to the compat rules file.
426 Symlinks to udevadm with the old command names are no longer resolved to
427 the udevadm commands.
429 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
432 The option "last_rule" does no longer exist. Its use breaks too many
433 things which expect to be run from independent later rules, and is an idication
434 that something needs to be fixed properly instead.
436 The gudev API is no longer marked as experimental,
437 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
438 is enabled by default now. Various projects already depend on introspection
439 information to bind dynamic languages to the gudev interfaces.
445 The udevadm trigger "--retry-failed" option, which is replaced since quite
446 a while by "--type=failed" is removed.
448 The failed tracking was not working at all for a few releases. The RUN
449 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
450 default is not to track any failing RUN executions.
452 New keymaps, new modem, hid2hci updated.
456 Fix possible crash in udevd when worker processes are busy, rules are
457 changed at the same time, and workers get killed to reload the rules.
463 Properties set with ENV{.FOO}="bar" are marked private by starting the
464 name with a '.'. They will not be stored in the database, and not be
465 exported with the event.
467 Firmware files are looked up in:
468 /lib/firmware/updates/$(uname -r)
469 /lib/firmware/updates
470 /lib/firmware/$(uname -r)
474 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
475 ata_id, instead of scsi_id, is the default tool now for ATA devices.
481 The configure options have changed because another library needs to be
482 installed in a different location. Instead of exec_prefix and udev_prefix,
483 libdir, rootlibdir and libexecdir are used. The Details are explained in
486 Event processes now get re-used after they handled an event. This reduces
487 the number of forks and the pressure on the CPU significantly, because
488 cloned event processes no longer cause page faults in the main daemon.
489 After the events have settled, a few worker processes stay around for
490 future events, all others get cleaned up.
492 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
493 Also inotify support is mandatory now to run udev.
495 The format of the queue exported by the udev damon has changed. There is
496 no longer a /dev/.udev/queue/ directory. The current event queue can be
497 accessed with udevadm settle and libudedv.
499 Libudev does not have the unstable API header anymore. From now on,
500 incompatible changes will be handled by bumping the library major version.
502 To build udev from the git tree gtk-doc is needed now. The tarballs will
503 build without it and contain the pre-built documentation. An online copy
505 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
507 The tools from the udev-extras repository have been merged into the main
508 udev repository. Some of the extras have larger external dependencies, and
509 they can be disabled with the configure switch --disable-extras.
515 The program vol_id and the library libvolume_id are removed from the
516 repository. Libvolume_id is merged with libblkid from the util-linux-ng
517 package. Persistent disk links for label and uuid depend on the
518 util-linux-ng version (2.15) of blkid now. Older versions of blkid
519 can not be used with udev.
521 Libudev allows to subscribe to udev events. To prevent unwanted messages
522 to be delivered, and waking up the subscribing process, a filter can be
523 installed, to drop messages inside a kernel socket filter. The filters
524 match on the <subsytem>:<devtype> properties of the device.
525 This is part of the ongoing effort to replace HAL, and switch current
526 users over to directly use libudev.
527 Libudev is still marked as experimental, and its interface might
528 eventually change if needed, but no major changes of the currently exported
529 interface are expected anymore, and a first stable release should happen
532 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
533 is not supported since while and udevd will log an error message at
534 startup. It should still be able to boot-up, but advanced rules and system
535 services which depend on the information not available in the old sysfs
536 format will fail to work correctly.
538 DVB device naming is supplied by the kernel now. In case older kernels
539 need to be supported, the old shell script should be added to a compat
546 The processed udev events get send back to the netlink socket. Libudev
547 provides access to these events. This is work-in-progress, to replace
548 the DeviceKit daemon functionality directly with libudev. There are
549 upcoming kernel changes to allow non-root users to subcribe to these
556 "udevadm settle" now optionally accepts a range of events to wait for,
557 instead of waiting for "all" events.
563 The installed watch for block device metadata changes is now removed
564 during event hadling, because some (broken) tools may be called from udev
565 rules and (wrongly) open the device with write access. After the finished
566 event handling the watch is restored.
572 Device nodes can be watched for changes with inotify with OPTIONS="watch".
573 If closed after being opened for writing, a "change" uevent will occur.
574 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
580 The udevadm test command has no longer a --force option, nodes and symlinks
581 are always updated with a test run now.
583 The udevd daemon can be started with --resolve-names=never to avoid all user
584 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
585 lookup user and groups every time events are handled.
591 We are currently merging the Ubuntu rules in the udev default rules,
592 and get one step closer to provide a common Linux /dev setup, regarding
593 device names, symlinks, and default device permissions. On udev startup,
594 we now expect the following groups to be resolvable to their ids with
596 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
597 LDAP setups need to make sure, that these groups are always resolvable at
598 bootup, with only the rootfs mounted, and without network access available.
600 Some systems may need to add some new, currently not used groups, or need
601 to add some users to new groups, but the cost of this change is minimal,
602 compared to the pain the current, rather random, differences between the
603 various distributions cause for upstream projects and third-party vendors.
605 In general, "normal" users who log into a machine should never be a member
606 of any such group, but the device-access should be managed by dynamic ACLs,
607 which get added and removed for the specific users on login/logout and
608 session activity/inactivity. These groups are only provided for custom setups,
609 and mainly system services, to allow proper privilege separation.
610 A video-streaming daemon uid would be a member of "audio" and "video", to get
611 access to the sound and video devices, but no "normal" user should ever belong
612 to the "audio" group, because he could listen to the built-in microphone with
613 any ssh-session established from the other side of the world.
615 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
616 which do not depend on the kernel device name. As usual, unique
617 devices - only a single one per product connected, or a real
618 USB serial number in the device - are always found with the same
619 name in the by-id/ directory.
620 Completely identical devices may overwrite their names in by-id/
621 and can only be found reliably in the by-path/ directory. Devices
622 specified by by-path/ must not change their connection, like the
623 USB port number they are plugged in, to keep their name.
625 To support some advanced features, Linux 2.6.22 is the oldest supported
626 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
627 supported. Older kernels should still work, and devices nodes should be
628 reliably created, but some rules and libudev will not work correctly because
629 the old kernels do not provide the expected information or interfaces.
635 Fix for a possible segfault while swapping network interface names in udev
642 The group "video" is part of the default rules now.
646 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
647 block devices in some cases. No common distro uses this option anymore,
648 and we do not get enough testing for this and recent udev versions. If
649 this option is not needed to run some old distro with a new kernel,
650 it should be disabled in the kernel config.
652 Bugfix for the $links substitution variable, which may crash if no links
653 are created. This should not happen in usual setups because we always
654 create /dev/{block,char}/ links.
656 The strings of the parsed rules, which are kept in memory, no longer
657 contain duplicate entries, or duplicate tails of strings. This, and the
658 new rules parsing/matching code reduces the total in-memory size of
659 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
662 The export of DEVTYPE=disk/partition got removed from the default
663 rules. This value is available from the kernel. The pnp shell script
664 modprobe hack is removed from the default rules. ACPI devices have _proper_
665 modalias support and take care of the same functionality.
666 Installations which support old kernels, but install current default
667 udev rules may want to add that to the compat rules file.
669 Libvolume_id now always probes for all known filesystems, and does not
670 stop at the first match. Some filesystems are marked as "exclusive probe",
671 and if any other filesytem type matches at the same time, libvolume_id
672 will, by default, not return any probing result. This is intended to prevent
673 mis-detection with conflicting left-over signatures found from earlier
674 file system formats. That way, we no longer depend on the probe-order
675 in case of multiple competing signatures. In some setups the kernel allows
676 to mount a volume with just the old filesystem signature still in place.
677 This may damage the new filesystem and cause data-loss, just by mounting
678 it. Because volume_id can not decide which one the correct signature is,
679 the wrong signatures need to be removed manually from the volume, or the
680 volume needs to be reformatted, to enable filesystem detection and possible
685 Fix segfault if compiled without optimization and dbg() does not get
686 compiled out and uses variables which are not available.
690 Bugfixes. (And maybe new bugs. :))
692 The rule matching engine got converted from a rule list to a token
693 array which reduced the in-memory rules representation of a full
694 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
695 Limits like 5 ENV and ATTR matches, and one single instance for most
696 other keys per rule are gone.
698 The NAME assignment is no longer special cased. If later rules assign
699 a NAME value again, the former value will be overwritten. As usual
700 for most other keys, the NAME value can be protected by doing a final
701 assignment with NAME:="<value>".
703 All udev code now uses libudev, which is also exported. The library
704 is still under development, marked as experimental, and its interface
705 may change as long as the DeviceKit integration is not finished.
707 Many thanks to Alan Jenkins for his continuous help, and finding and
708 optimizing some of the computing expensive parts.
714 Kernel devices and device nodes are connected now by reverse indizes in
715 /sys and /dev. A device number retrieved by a stat() or similar, the
716 kernel device directory can be found by looking up:
717 /sys/dev/{block,char}/<maj>:<min>
718 and the device node of the same device by looking up:
719 /dev/{block,char}/<maj>:<min>
723 Fix recently introduced bug, which caused a compilation without large
724 file support, where vol_id does not recognize raid signatures at the end
727 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
728 Seems some kernel versions prevent the creation of the ieee-* links,
729 so people used the scsi-* link which disappeared now.
731 More libudev work. Almost all udevadm functionality comes from libudev
734 udevadm trigger has a new option --type, which allows to trigger events
735 for "devices", for "subsystems", or "failed" devices. The old option
736 --retry-failed" still works, but is no longer mentioned in the man page.
742 The udevadm info --device-id-of-file= output has changed to use
743 the obvious format. Possible current users should use the --export
744 option which is not affected.
746 The old udev commands symlinks to udevadm are not installed, if
747 these symlinks are used, a warning is printed.
753 Optical drive's media is no longer probed for raid signatures,
754 reading the end of the device causes some devices to malfunction.
755 Also the offset of the last session found is used now to probe
758 The volume_id library got a major version number update to 1,
759 some deprecated functions are removed.
761 A shared library "libudev" gets installed now to provide access
762 to udev device information. DeviceKit, the successor of HAL, will
763 need this library to access the udev database and search sysfs for
765 The library is currently in an experimental state, also the API is
766 expected to change, as long as the DeviceKit integration is not
771 We use ./configure now. See INSTALL for details. Current
774 "/usr" - prefix for man pages, include files
776 "" - the root filesystem, prefix for libs and binaries
780 "lib" - directory name for libraries, not a path name
781 multilib 64bit systems may use "lib64" instead of "lib"
783 compile-in verbose debug messages
785 disable all logging and compile-out all log strings
787 link against SELInux libraries, to set the expected context
790 In the default rules, the group "disk" gets permissions 0660 instead
791 of 0640. One small step closer to unify distro rules. Some day, all
792 distros hopefully end up with the same set of rules.
794 No symlinks to udevadm are installed anymore, if they are still needed,
795 they should be provided by the package.
801 Default udev rules, which are not supposed to be edited by the user, should
802 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
803 the udev package and will be replaced with an update. Udev will pick up rule
805 /lib/udev/rules.d/ - default installed rules
806 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
807 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
808 It does not matter in which directory a rule file lives, all files are sorted
811 To help creating /dev/root, we have now:
812 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
815 In case the current --device-id-of-file is already used, please switch to
816 the --export format version, it saves the output parsing and the old
817 format will be changed to use ':' as a separator, like the format in the
822 Fix cdrom_id to properly recognize blank media.
828 Tape drive id-data is queried from /dev/bsg/* instead of the tape
829 nodes. This avoids rewinding tapes on open().
835 The symlinks udevcontrol and udevtrigger are no longer installed by
838 The scsi_id program does not depend on sysfs anymore. It can speak
839 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
840 data, which should solve some old problems with tape devices, where
841 we better do not open all tape device nodes to identify the device.
847 The cdrom_id program is replaced by an advanced version, which can
848 detect most common device types, and also properties of the inserted
849 media. This is part of moving some basic functionality from HAL into
850 udev (and the kernel).
856 The last WAIT_FOR_SYSFS rule is removed from the default rules.
858 The symlinks to udevadm for the debugging tools: udevmonitor and
859 udevtest are no longer created.
861 The symlinks to the udevadm man page for the old tool names are
864 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
865 should be prefixed with '@' to indicate that the path is not a
876 Udevstart is removed from the tree, it did not get installed for
877 a long time now, and is long replaced by trigger and settle.
883 All udev tools are merged into a single binary called udevadm.
884 The old names of the tools are built-in commands in udevadm now.
885 Symlinks to udevadm, with the names of the old tools, provide
886 the same functionality as the standalone tools. There is also
887 only a single udevadm.8 man page left for all tools.
889 Tools like mkinitramfs should be checked, if they need to include
890 udevadm in the list of files.
900 The etc/udev/rules.d/ directory now contains a default set of basic
901 udev rules. This initial version is the result of a rules file merge
902 of Fedora and openSUSE. For these both distros only a few specific
903 rules are left in their own file, named after the distro. Rules which
904 are optionally installed, because they are only valid for a specific
905 architecture, or rules for subsystems which are not always used are
906 in etc/udev/packages/.
912 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
913 actions by dynamically created rules.
915 SYMLINK=="<value>" matches agains the entries in the list of
916 currently defined symlinks. The links are not created in the
917 filesystem at that point in time, but the values can be matched.
919 RUN{ignore_error}+="<program>" will ignore any exit code from the
920 program and not record as a failed event.
926 Final merge of patches/features from the Ubuntu package.
932 Control characters in filesystem label strings are no longer silenty
933 removed, but hex-encoded, to be able to uniquely identify the device
934 by its symlink in /dev/disk/by-label/.
935 If libvolume_id is used by mount(8), LABEL= will work as expected,
936 if slashes or other characters are used in the label string.
938 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
939 can be specified now. The TEST key accepts an optional mode mask
940 TEST{0100}=="<is executable file>".
942 Scsi_id now supports a mode without expecting scsi-specific sysfs
943 entries to allow the extraction of cciss-device persistent properties.
949 In the future, we may see uuid's which are just simple character
950 strings (see the DDF Raid Specification). For that reason vol_id now
951 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
952 the creation of symlinks, the *_SAFE values ensure, that no control
953 or whitespace characters are used in the filename.
955 Possible users of libvolume_id, please use the volume_id_get_* functions.
956 The public struct will go away in a future release of the library.
962 Removal of useless extras/eventrecorder.sh.
972 The directory multiplexer for dev.d/ and hotplug.d are finally removed
973 from the udev package.
979 Symlinks can have priorities now, the priority is assigned to the device
980 and specified with OPTIONS="link_priority=100". Devices with higher
981 priorities overwrite the symlinks of devices with lower priorities.
982 If the device that currently owns the link, goes away, the symlink
983 will be removed, and recreated, pointing to the next device with the
984 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
985 more reliable, if multiple devices contain the same metadata and overwrite
988 The dasd_id program is removed from the udev tree, and dasdinfo, with the
989 needed rules, are part of the s390-tools now.
991 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
992 we may get the scsi sysfs mess fixed some day, and this will only catch
993 the devices we are looking for.
995 USB serial numbers for storage devices have the target:lun now appended,
996 to make it possibble to distinguish broken multi-lun devices with all
997 the same SCSI identifiers.
999 Note: The extra "run_directory" which searches and executes stuff in
1000 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
1001 with the next release. Make sure, that you don't use it anymore, or
1002 provides your own implementation of that inefficient stuff.
1003 We are tired of reports about a "slow udev", because these directories
1004 contain stuff, that runs with _every_ event, instead of using rules,
1005 that run programs only for the matching events.
1015 DRIVER== will match only for devices that actually have a real
1016 driver. DRIVERS== must be used, if parent devices should be
1017 included in the match.
1019 Libvolume_id's "linux_raid" detection needed another fix.
1027 Add additional check to volume_id detection of via_raid, cause
1028 some company decided to put a matching pattern all over the empty
1029 storage area of their music players.
1033 Fix path_id for SAS devices.
1037 The udev daemon can be started with --debug-trace now, which will
1038 execute all events serialized to get a chance to catch a possible
1039 action that crashes the box.
1041 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1042 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1043 are excluded from the warning. Referencing parent attributes directly
1044 may break when something in the kernel driver model changes. Udev will
1045 just find the attribute by walking up the parent chain.
1047 Udevtrigger now sorts the list of devices depending on the device
1048 dependency, so a "usb" device is triggered after the parent "pci"
1053 Revert persistent-storage ata-serial '_' '-' replacement.
1059 Udevtrigger can now filter the list of devices to be triggered. Matches
1060 for subsystems or sysfs attributes can be specified.
1062 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1063 zero-sized files to avoid pointing to /sys and confuse broken tools which
1064 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1067 The rules and scripts to create udev rules for persistent network
1068 devices and optical drives are in the extras/rules_generator directory
1069 now. If you use something similar, please consider replacing your own
1070 version with this, to share the support effort. The rule_generator
1071 installs its own rules into /etc/udev/rules.d.
1073 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1074 the rule_generator depends on cdrom_id to be called in an earlier rule.
1080 Renaming of some key names (the old names still work):
1081 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1082 (The behavior of the key DRIVER will change soon in one of the next
1083 releases, to match only the event device, please switch to DRIVERS
1084 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1086 With the new key names, we have a more consistent and simpler scheme.
1087 We can match the properties of the event device only, with: KERNEL,
1088 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1089 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1090 longer mentioned in the man page and should be switched in the rule
1093 ATTR{file}="value" can be used now, to write to a sysfs file of the
1094 event device. Instead of:
1095 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1097 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1099 All the PHYSDEV* keys are deprecated and will be removed from a
1101 PHYDEVPATH - is the path of a parent device and should not be
1103 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1104 matched with SUBSYSTEMS==
1105 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1106 Newer kernels will have DRIVER in the environment,
1107 for older kernels udev puts in. Class device will
1108 no longer carry this property of a parent and
1109 DRIVERS== can be used to match such a parent value.
1110 Note that ENV{DRIVER} is only available for a few bus devices, where
1111 the driver is already bound at device event time. On coldplug, the
1112 events for a lot devices are already bound to a driver, and they will have
1113 that value set. But on hotplug, at the time the kernel creates the device,
1114 it can't know what driver may claim the device after that, therefore
1115 in most cases it will be empty.
1117 Failed events should now be re-triggered with:
1118 udevtrigger --retry-failed.
1119 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1120 files private to the udev tools. We may need to switch the current symlink
1121 target, cause some obviously broken tools try to scan all files in /dev
1122 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1123 million times. This takes ages on slow boxes.
1125 The udevinfo attribute walk (-a) now works with giving a device node
1126 name (-n) instead of a devpath (-p). The query now always works, also when
1127 no database file was created by udev.
1129 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1130 getpwnam() and getgrnam() now. One of the next releases will depend on
1131 fnmatch() and may use getopt_long().
1135 Bugfixes and small improvements.
1139 Fix path_id for recent kernels.
1145 Added support for swapping network interface names, by temporarily
1146 renaming the device and wait for the target name to become free.
1150 The built-in MODALIAS key and substitution is removed.
1154 The binary firmware helper is replaced by the usual simple
1155 shell script. Udevsend is removed from the tree.
1163 Some more keys require the correct use of '==' and '=' depending
1164 on the kind of operation beeing an assignment or a match. Rules
1165 with invalid operations are skipped and logged to syslog. Please
1166 test with udevtest if the parsing of your rules throws errors and
1167 fix possibly broken rules.
1171 Provide "udevsettle" to wait for all current udev events to finish.
1172 It also watches the current kernel netlink queue by comparing the
1173 even sequence number to make sure that there are no current pending
1174 events that have not already arrived in the daemon.
1178 Fix rule to skip persistent rules for removable IDE devices, which
1179 also skipped optical IDE drives.
1181 All *_id program are installed in /lib/udev/ by default now.
1183 No binary is stripped anymore as this should be done in the
1184 packaging process and not at build time.
1186 libvolume_id is provided as a shared library now and vol_id is
1187 linked against it. Also one of the next HAL versions will require
1188 this library, and the HAL build process will also require the
1189 header file to be installed. The copy of the same code in HAL will
1190 be removed to have only a single copy left on the system.
1194 Add persistent links for SCSI tapes. The rules file is renamed
1195 to 60-persistent-storage.rules.
1197 Create persistent path for usb devices. Can be used for all sorts
1198 of devices that can't be distinguished by other properties like
1199 multiple identical keyboards and mice connected to the same box.
1201 Provide "udevtrigger" program to request events on coldplug. The
1202 shell script is much too slow with thousends of devices.
1206 Fix persistent disk rules to exclude removable IDE drives.
1208 Warn if %e, $modalias or MODALIAS is used.
1212 Fix queue export, which wasn't correct for subsequent add/remove
1213 events for the same device.
1217 Fix cramfs detection on big endian.
1219 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1224 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1225 attributes were only checked at the parent device that matched the
1226 by BUS requested subsystem. Fix it to also look at the device we
1227 received the event for.
1229 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1234 Fix a bug where NAME="" would prevent RUN from beeing executed.
1236 RUN="/bin/program" does not longer automatically add the subsystem
1237 as the first parameter. This is from the days of /sbin/hotplug
1238 which is dead now and it's just confusing to need to add a space at
1239 the end of the program name to prevent this.
1240 If you use rules that need the subsystem as the first parameter,
1241 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1242 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1246 The udev man page has moved to udev(7) as it does not describe a command
1247 anymore. The programs udev, udevstart and udevsend are no longer installed
1248 by default and must be copied manually, if they should be installed or
1249 included in a package.
1251 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1252 the ignore rule was applied.
1254 More preparation for future sysfs changes. usb_id and scsi_id no longer
1255 depend on a magic order of devices in the /devices chain. Specific devices
1256 should be requested by their subsytem.
1258 This will always find the scsi parent device without depending on a specific
1260 dev = sysfs_device_get(devpath);
1261 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1263 The "device" link in the current sysfs layout will be automatically
1264 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1265 parent in the devpath. If a device is requested by it's symlink, like all
1266 class devices in the new sysfs layout will look like, it gets automatically
1267 resolved and substituted with the real devpath and not the symlink path.
1270 A similar logic must be applied to _all_ sysfs users, including
1271 scripts, that search along parent devices in sysfs. The explicit use of
1272 the "device" link must be avoided. With the future sysfs layout all
1273 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1274 back to the "class" or the "bus". The layout of the parent devices in
1275 /devices is not necessarily expected to be stable across kernel releases and
1276 searching for parents by their subsystem should make sysfs users tolerant
1277 for changed parent chains.
1281 Prepare udev to work with the experimental kernel patch, that moves
1282 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1284 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1285 moving the class devices to /sys/devices.
1287 Thanks again to Marco for help finding a hopefully nice compromise
1288 to make %b simpler and working again.
1292 Complete removal of libsysfs, replaced by simple helper functions
1293 which are much simpler and a bit faster. The udev daemon operatesentirely
1294 on event parameters and does not use sysfs for simple rules anymore.
1295 Please report any new bugs/problems, that may be caused by this big
1296 change. They will be fixed immediately.
1298 The enumeration format character '%e' is deprecated and will be
1299 removed sometimes from a future udev version. It never worked correctly
1300 outside of udevstart, so we can't use it with the new parallel
1301 coldplug. A simple enumeration is as useless as the devfs naming
1302 scheme, just get rid of both if you still use it.
1304 MODALIAS and $modalias is not needed and will be removed from one of
1305 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1306 the sysfs "modalias" value.
1308 Thanks a lot to Marco for all his help on finding and fixing bugs.
1312 Let scsi_id request libata drive serial numbers from page 0x80.
1314 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1315 added /dev/disk/by-name/* for device mapper device names.
1317 Removed %e from the man page. It never worked reliably outside
1318 of udevstart and udevstart is no longer recommended to use.
1322 Symlinks are now exported to the event environment. Hopefully it's no
1323 longer needed to run udevinfo from an event process, like it was
1324 mentioned on the hotplug list:
1325 UDEV [1134776873.702967] add@/block/sdb
1328 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1332 Fix a problem if udevsend is used as the hotplug handler and tries to use
1333 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1334 and this kind of problems will hopefully go away soon.
1338 All built-in logic to work around bad sysfs timing is removed with this
1339 version. The need to wait for sysfs files is almost fixed with a kernel
1340 version that doesn't work with this udev version anyway. Until we fix
1341 the timing of the "bus" link creation, the former integrated logic should
1342 be emulated by a rule placed before all other rules:
1343 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1345 The option "udev_db" does no longer exist. All udev state will be in
1346 /$udev_root/.udev/ now, there is no longer an option to set this
1348 If the init script or something else used this value, just depend on
1349 this hardcoded path. But remember _all_content_ of this directory is
1350 still private to udev and can change at any time.
1352 Default location for rule sripts and helper programs is now: /lib/udev/.
1353 Everything that is not useful on the commandline should go into this
1354 directory. Some of the helpers in the extras folder are installed there
1355 now. The rules need to be changed, to find the helpers there.
1357 Also /lib/udev/devices is recommended as a directory where packages or
1358 the user can place real device nodes, which get copied over to /dev at
1359 every boot. This should replace the various solutions with custom config
1362 Udevsend does no longer start the udev daemon. This must be done with
1363 the init script that prepares /dev on tmpfs and creates the initial nodes,
1364 before starting the daemon.
1368 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1371 The copy of klibc is removed. A systemwide installed version of klibc
1372 should be used to build a klibc udev now.
1376 NAME="" will not create any nodes, but execute RUN keys. To completely
1377 ignore an event the OPTION "ignore_device" should be used.
1379 After removal of the reorder queue, events with a TIMEOUT can be executed
1380 without any queuing now.
1384 Fixed bug in udevd, if inotify is not available. We depend on netlink
1385 uevents now, kernels without that event source will not work with that
1386 version of udev anymore.
1390 The rule parsing happens now in the daemon once at startup, all udev
1391 event processes inherit the already parsed rules from the daemon.
1392 It is shipped with SUSE10.0 and reduces heavily the system load at
1393 startup. The option to save precompiled rules and let the udev process
1394 pick the them up is removed, as it's no longer needed.
1396 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1397 device. Libsysfs is changed to "translate" the requested link into the
1398 real device path, as it would happen with the hotplug event. Otherwise
1399 device removal and the udev database will not work.
1401 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1404 A few improvements for vol_id, the filesytem probing code.
1408 Fix a stupid typo in extras/run_directory for "make install".
1410 scsi_id creates the temporary devnode now in /dev for usage with a
1411 non-writable /tmp directory.
1413 The uevent kernel socket buffer can carry app. 50.000 events now,
1414 let's see who can break this again. :)
1416 The upcoming kernel will have a new input driver core integration.
1417 Some class devices are now symlinks to the real device. libsysfs
1418 needs a fix for this to work correctly. Udevstart of older udev
1419 versions will _not_ create these devices!
1423 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1428 A bunch of mostly trivial bugfixes. From now on no node name or
1429 symlink name can contain any character than plain whitelisted ascii
1430 characters or validated utf8 byte-streams. This is needed for the
1431 /dev/disk/by-label/* links, because we import untrusted data and
1432 export it to the filesystem.
1436 More bugfixes. If udevd was started from the kernel, we don't
1437 have stdin/stdout/stderr, which broke the forked tools in some
1442 Bugfix. udevstart event ordering was broken for a long time.
1443 The new run_program() uncovered it, because /dev/null was not
1444 available while we try to run external programs.
1445 Now udevstart should create it before we run anything.
1449 Minor bugfixes and some distro rules updates. If you don't have the
1450 persistent disk rules in /dev/disk/by-*/* on your distro, just
1451 grab it from here. :)
1455 We can use socket communication now to pass events from udev to
1457 RUN+="socket:/org/freedesktop/hal/udev_event"
1458 will pass the whole udev event to the HAL daemon without the need
1459 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1463 Mostly bugfixes and see ChangeLog.
1465 The test for the existence of an environment value should be
1467 ENV{KEY}=="*" to ENV{KEY}=="?*"
1468 because "*" will not fail anymore, if the key does not exist or
1473 Bugfixes and a few tweaks described in the ChangeLog.
1477 Mostly a Bugfix release.
1479 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1480 timing with custom rules.
1484 We changed the internal rule storage format. Our large rule files took
1485 2 MB of RAM, with the change we are down to 99kB.
1487 If the device-node has been created with default name and no symlink or
1488 options are to remenber, it is not longer stored in the udevdb. HAL will
1489 need to be updated to work correctly with that change.
1491 To overrride optimization flags, OPTFLAGS may be used now.
1499 Major changes happened with this release. The goal is to take over the
1500 complete kernel-event handling and provide a more efficient way to dispatch
1501 kernel events. Replacing most of the current shell script logic and the
1502 kernel forked helper with a netlink-daemon and a rule-based event handling.
1504 o udevd listens to netlink events now. The first valid netlink event
1505 will make udevd ignore any message from udevsend that contains a
1506 SEQNUM, to avoid duplicate events. The forked events can be disabled
1508 echo "" > /proc/sys/kernel/hotplug
1509 For full support, the broken input-subsytem needs to be fixed, not to
1510 bypass the driver core.
1512 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1513 removed from udev itself and must be emulated by calling small
1514 helper binaries provided in the extras folder:
1515 make EXTRAS=extras/run_directory/
1516 will build udev_run_devd and udev_run_hotplugd, which can be called
1517 from a rule if needed:
1518 RUN+="/sbin/udev_run_hotplugd"
1519 The recommended way to handle this is to convert all the calls from
1520 the directories to explicit udev rules and get completely rid of the
1521 multiplexing. (To catch a ttyUSB event, you now no longer need to
1522 fork and exit 300 tty script instances you are not interested in, it
1523 is just one rule that matches exactly the device.)
1525 o udev handles now _all_ events not just events for class and block
1526 devices, this way it is possible to control the complete event
1527 behavior with udev rules. Especially useful for rules like:
1528 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1530 o As used in the modalias rule, udev supports now textual
1531 substitution placeholder along with the usual format chars. This
1532 needs to be documented, for now it's only visible in udev_rules_parse.c.
1534 o The rule keys support now more operations. This is documented in the
1535 man page. It is possible to add values to list-keys like the SYMLINK
1536 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1537 Also "final"-assignments are supported by using KEY:="value", which will
1538 prevent changing the key by any later rule.
1540 o kernel 2.6.12 has the "detached_state" attribute removed from
1541 sysfs, which was used to recognize sysfs population. We switched that
1542 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1543 Running this udev version on older kernels may cause a short delay for
1546 o To provide infrastructure for persistent device naming, the id programs:
1547 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1548 to export the probed data in environment key format:
1549 pim:~ # /sbin/ata_id --export /dev/hda
1550 ID_MODEL=HTS726060M9AT00
1551 ID_SERIAL=MRH401M4G6UM9B
1552 ID_REVISION=MH4OA6BA
1554 The following rules:
1555 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1556 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1559 kay@pim:~> tree /dev/disk
1562 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1563 | `-- IBM-Memory_Key -> ../../sda
1565 | |-- swap -> ../../hda1
1566 | |-- date -> ../../sda1
1567 | `-- home -> ../../hda3
1569 |-- 2E08712B0870F2E7 -> ../../hda3
1570 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1571 |-- E845-7A89 -> ../../sda1
1572 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1574 The IMPORT= operation will import these keys in the environment and make
1575 it available for later PROGRAM= and RUN= executed programs. The keys are
1576 also stored in the udevdb and can be queried from there with one of the
1579 o A few binaries are silently added to the repository, which can be used
1580 to replay kernel events from initramfs instead of using coldplug. udevd
1581 can be instructed now to queue-up events while the stored events from
1582 initramfs are filled into the udevd-queue. This code is still under
1583 development and there is no documentation now besides the code itself.
1584 The additional binaries get compiled, but are not installed by default.
1586 o There is also a temporary fix for a performance problem where too many
1587 events happen in parallel and every event needs to parse the rules.
1588 udev can now read precompiled rules stored on disk. This is likely to be
1589 replaced by a more elegant solution in a future udev version.
1593 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1594 Fix for libsysfs not to expect this file was added.
1598 All rules are applied now, but only the first matching rule with a NAME-key
1599 will be applied. All later rules with NAME-key are completely ignored. This
1600 way system supplied symlinks or permissions gets applied to user-defined
1604 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1605 to some rules, to keep the old behavior.
1607 The rules are read on "remove"-events too. That makes is possible to match
1608 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1609 instruct udev to ignore an event (OPTIONS="ignore_device").
1610 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1612 The new RUN-key supports rule-based execution of programs after device-node
1613 handling. This is meant as a general replacement for the dev.d/-directories
1614 to give fine grained control over the execution of programs.
1616 The %s{}-sysfs format char replacement values are searched at any of the
1617 devices in the device chain now, not only at the class-device.
1619 We support log priority levels now. The value udev_log in udev.conf is used
1620 to determine what is printed to syslog. This makes it possible to
1621 run a version with compiled-in debug messages in a production environment
1622 which is sometimes needed to find a bug.
1623 It is still possible to supress the inclusion of _any_ syslog usage with
1624 USE_LOG=false to create the smallest possible binaries if needed.
1625 The configured udev_log value can be overridden with the environment variable
1630 Possible use of a system-wide klibc:
1631 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1632 will link against an external klibc and our own version will be ignored.
1636 We support an unlimited count of symlinks now.
1638 If USE_STATIC=true is passed to a glibc build, we link statically and use
1639 a built-in userdb parser to resolve user and group names.
1641 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1642 we walk up the chain of physical devices to find a match.
1644 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1645 easy to skip certain attribute matches without composing rules with weird
1646 character class negations like:
1647 KERNEL="[!s][!c][!d]*"
1648 this can now be replaced with:
1650 The current simple '=' is still supported, and should work as it does today,
1651 but existing rules should be converted if possible, to be better readable.
1653 We have new ENV{}== key now, to match against a maximum of 5 environment
1656 udevstart is its own binary again, because we don't need co carry this araound
1657 with every forked event.
~ianmdlvl / elogind.git / blob