3 A writable /run directory (tmpfs) is required now for a fully functional
6 The default 'configure' install locations have changed. Packages for systems
7 with the historic / vs. /usr split need to be adapted, otherwise udev will
8 be installed in /usr and not work properly. Example configuration options are
11 The default install location of the 'udevadm' tool moved from 'sbin'
12 to /usr/bin. Some tools expect udevadm in 'sbin'. A symlink to udevadm
13 needs to be manually created if needed.
15 Kernel modules are now loaded directly by linking udev to 'libkmod'. The
16 'modprobe' tool is no longer executed by udev.
18 The 'blkid' tool is no longer executed from udev rules. Udev links
19 directly to libblkid now.
21 Firmware is loaded natively by udev now, the external 'firmware' binary
24 All built-in tools can be listed and tested with 'udevadm test-builtin'.
26 The 'udevadm control --reload-rules' option has been renamed to '--reload'.
27 It reloads the kernel module configuration.
29 The systemd socket files use PassCred=yes, which requires systemd
32 The udev build system only creates a .xz tarball now.
42 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
43 and non-dracut initramfs image generators need to change the init
44 scripts. Alternatively the udev build needs to move udevd back to
45 /sbin or create a symlink in /sbin, which is not done by default.
47 The path_id, usb_id, input_id tools are built-in commands now and
48 the stand-alone tools do not exist anymore. Static lists of file in
49 initramfs generators need to be updated. For testing, the commands
50 can still be executed standalone with 'udevadm test-builtin <cmd>'.
52 The fusectl filesystem is no longer mounted directly from udev.
53 Systemd systems will take care of mounting fusectl and configfs
54 now. Non-systemd systems need to ship their own rule if they
55 need these filesystems auto-mounted.
57 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
59 The support for 'udevadm trigger --type=failed, and the
60 RUN{fail_event_on_error} attribute was removed.
62 The udev control socket is now created in /run/udev/control
63 and no longer as an abstract namespace one.
65 The rules to create persistent network interface and cdrom link
66 rules automatically in /etc/udev/rules.d/ have been disabled by
67 default. Explicit configuration will be required for these use
68 cases, udev will no longer try to write any persistent system
69 configuration from a device hotplug path.
75 The udev-acl extra is no longer enabled by default now. To enable it,
76 --enable-udev_acl needs to be given at ./configure time. On systemd
77 systems, the udev-acl rules prevent it from running as the functionality
84 Udev now enables kernel media-presence polling if available. Part
85 of udisks optical drive tray-handling moved to cdrom_id: The tray
86 is locked as soon as a media is detected to enable the receiving
87 of media-eject-request events. Media-eject-request events will
90 Libudev enumerate is now able to enumerate a subtree of a given
93 The mobile-action-modeswitch modeswitch tool was deleted. The
94 functionality is provided by usb_modeswitch now.
100 The systemd service files require systemd version 28. The systemd
101 socket activation make it possible now to start 'udevd' and 'udevadm
102 trigger' in parallel.
106 Fix bug in control message handling, which can lead to a failing
107 udevadm control --exit. Thanks to Jürg Billeter for help tracking
114 We require at least Linux kernel 2.6.32 now. Some platforms might
115 require a later kernel that supports accept4() and similar, or
116 need to backport the trivial syscall wiring to the older kernels.
118 The hid2hci tool moved to the bluez package and was removed.
120 Many of the extras can be --enable/--disabled at ./configure
121 time. The --disable-extras option was removed. Some extras have
122 been disabled by default. The current options and their defaults
123 can be checked with './configure --help'.
129 Udev logs a warning now if /run is not writable at udevd
130 startup. It will still fall back to /dev/.udev, but this is
131 now considered a bug.
133 The running udev daemon can now cleanly shut down with:
134 udevadm control --exit
136 Udev in initramfs should clean the state of the udev database
137 with: udevadm info --cleanup-db which will remove all state left
138 behind from events/rules in initramfs. If initramfs uses
139 --cleanup-db and device-mapper/LVM, the rules in initramfs need
140 to add OPTIONS+="db_persist" for all dm devices. This will
141 prevent removal of the udev database for these devices.
143 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
144 120 seconds per process. If that timeout is reached the spawned
145 process will be killed. The event timeout can be overwritten with
148 If systemd is used, udev gets now activated by netlink data.
149 Systemd will bind the netlink socket which will buffer all data.
150 If needed, such setup allows a seemless update of the udev daemon,
151 where no event can be lost during a udevd update/restart.
152 Packages need to make sure to: systemctl stop udev.socket udev.service
153 or 'mask' udev.service during the upgrade to prevent any unwanted
154 auto-spawning of udevd.
155 This version of udev conflicts with systemd version below 25. The
156 unchanged service files will not wirk correctly.
162 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
163 /run mountpoint is supposed to be a tmpfs mounted during early boot,
164 available and writable to for all tools at any time during bootup,
165 it replaces /var/run/, which should become a symlink some day.
167 If /run does not exist, or is not writable, udev will fall back using
170 On systemd systems with initramfs and LVM used, packagers must
171 make sure, that the systemd and initramfs versions match. The initramfs
172 needs to create the /run mountpoint for udev to store the data, and
173 mount this tmpfs to /run in the rootfs, so the that the udev database
174 is preserved for the udev version started in the rootfs.
176 The command 'udevadm info --convert-db' is gone. The udev daemon
177 itself, at startup, converts any old database version if necessary.
179 The systemd services files have been reorganized. The udev control
180 socket is bound by systemd and passed to the started udev daemon.
181 The udev-settle.service is no longer active by default. Services which
182 can not handle hotplug setups properly need to actively pull it in, to
183 act like a barrier. Alternatively the settle service can be unconditionally
184 'systemctl'enabled, and act like a barrier for basic.target.
186 The fstab_import callout is no longer built or installed. Udev
187 should not be used to mount, does not watch changes to fstab, and
188 should not mirror fstab values in the udev database.
194 New and updated keymaps.
200 The udev database has changed, After installation of a new udev
201 version, 'udevadm info --convert-db' should be called, to let the new
202 udev/libudev version read the already stored data.
204 udevadm now supports quoting of property values, and prefixing of
206 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
209 MY_DEVNAME='/dev/sda'
213 libudev now supports:
214 udev_device_get_is_initialized()
215 udev_enumerate_add_match_is_initialized()
216 to be able to skip devices the kernel has created , but udev has
219 libudev now supports:
220 udev_device_get_usec_since_initialized()
221 to retrieve the "age" of a udev device record.
223 GUdev supports a more generic GUdevEnumerator class, udev TAG
224 handling, device initialization and timestamp now.
226 The counterpart of /sys/dev/{char,block}/$major:$minor,
227 /dev/{char,block}/$major:$minor symlinks are now unconditionally
228 created, even when no rule files exist.
230 New and updated keymaps.
236 GUdev moved from /usr to /.
246 Persistent network naming rules are disabled inside of Qemu/KVM now.
248 New and updated keymaps.
250 Udev gets unconditionally enabled on systemd installations now. There
251 is no longer the need to to run 'systemctl enable udev.service'.
265 New and fixed keymaps.
267 Install systemd service files if applicable.
273 All distribution specific rules are removed from the udev source tree,
274 most of them are no longer needed. The Gentoo rules which allow to support
275 older kernel versions, which are not covered by the default rules anymore
276 has moved to rules/misc/30-kernel-compat.rules.
282 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
283 was removed from udevd.
285 Udevd now checks the kernel commandline for the following variables:
286 udev.log-priority=<syslog priority>
287 udev.children-max=<maximum number of workers>
288 udev.exec-delay=<seconds to delay the execution of RUN=>
289 to help debuging coldplug setups where the loading of a kernel
290 module crashes the system.
292 The subdirectory in the source tree rules/packages has been renamed to
293 rules/arch, anc contains only architecture specific rules now.
303 Now the udev daemon itself, does on startup:
304 - copy the content of /lib/udev/devices to /dev
305 - create the standard symlinks like /dev/std{in,out,err},
306 /dev/core, /dev/fd, ...
307 - use static node information provided by kernel modules
308 and creates these nodes to allow module on-demand loading
309 - possibly apply permissions to all ststic nodes from udev
310 rules which are annotated to match a static node
312 The default mode for a device node is 0600 now to match the kernel
313 created devtmpfs defaults. If GROUP= is specified and no MODE= is
314 given the default will be 0660.
320 Udev now gradually starts to pass control over the primary device nodes
321 and their names to the kernel, and will in the end only manage the
322 permissions of the node, and possibly create additional symlinks.
323 As a first step NAME="" will be ignored, and NAME= setings with names
324 other than the kernel provided name will result in a logged warning.
325 Kernels that don't provide device names, or devtmpfs is not used, will
326 still work as they did before, but it is strongly recommended to use
327 only the same names for the primary device node as the recent kernel
328 provides for all devices.
332 Fix broken firmware loader search path.
338 "udevadm trigger" defaults to "change" events now instead of "add"
339 events. The "udev boot script" might need to add "--action=add" to
340 the trigger command if not already there, in case the initial coldplug
341 events are expected as "add" events.
343 The option "all_partitons" was removed from udev. This should not be
344 needed for usual hardware. Udev can not safely make assumptions
345 about non-existing partition major/minor numbers, and therefore no
346 longer provide this unreliable and unsafe option.
348 The option "ignore_remove" was removed from udev. With devtmpfs
349 udev passed control over device nodes to the kernel. This option
350 should not be needed, or can not work as advertised. Neither
351 udev nor the kernel will remove device nodes which are copied from
352 the /lib/udev/devices/ directory.
354 All "add|change" matches are replaced by "!remove" in the rules and
355 in the udev logic. All types of events will update possible symlinks
356 and permissions, only "remove" is handled special now.
358 The modem modeswitch extra was removed and the external usb_modeswitch
359 program should be used instead.
361 New and fixed keymaps.
371 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
372 depend on the current sysfs layout and the information not available in the
373 deprecated layout. All remaining support for the deprecated sysfs layout is
378 Fix for a possible endless loop in the new input_id program.
384 The option "ignore_device" does no longer exist. There is no way to
385 ignore an event, as libudev events can not be suppressed by rules.
386 It only prevented RUN keys from being executed, which results in an
387 inconsistent behavior in current setups.
389 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
390 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
393 The support for the deprecated IDE devices has been removed from the
394 default set of rules. Distros who still care about non-libata drivers
395 need to add the rules to the compat rules file.
397 The ID_CLASS property on input devices has been replaced by the more accurate
398 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
399 determined by the new "input_id" prober now. Some devices, such as touchpads,
400 can have several classes. So if you previously had custom udev rules which e. g.
401 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
402 ENV{ID_INPUT_KEYBOARD}=="?*".
408 To support DEVPATH strings larger than the maximum file name length, the
409 private udev database format has changed. If some software still reads the
410 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
411 Please do not port anything to the new format again, everything in /dev/.udev
412 is and always was private to udev, and may and will change any time without
415 Multiple devices claiming the same names in /dev are limited to symlinks
416 only now. Mixing identical symlink names and node names is not supported.
417 This reduces the amount of data in the database significantly.
419 NAME="%k" causes a warning now. It's is and always was completely superfluous.
420 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
423 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
424 if they are not the default. To support older kernels, the NAME= rules need to
425 be added to the compat rules file.
427 Symlinks to udevadm with the old command names are no longer resolved to
428 the udevadm commands.
430 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
433 The option "last_rule" does no longer exist. Its use breaks too many
434 things which expect to be run from independent later rules, and is an idication
435 that something needs to be fixed properly instead.
437 The gudev API is no longer marked as experimental,
438 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
439 is enabled by default now. Various projects already depend on introspection
440 information to bind dynamic languages to the gudev interfaces.
446 The udevadm trigger "--retry-failed" option, which is replaced since quite
447 a while by "--type=failed" is removed.
449 The failed tracking was not working at all for a few releases. The RUN
450 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
451 default is not to track any failing RUN executions.
453 New keymaps, new modem, hid2hci updated.
457 Fix possible crash in udevd when worker processes are busy, rules are
458 changed at the same time, and workers get killed to reload the rules.
464 Properties set with ENV{.FOO}="bar" are marked private by starting the
465 name with a '.'. They will not be stored in the database, and not be
466 exported with the event.
468 Firmware files are looked up in:
469 /lib/firmware/updates/$(uname -r)
470 /lib/firmware/updates
471 /lib/firmware/$(uname -r)
475 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
476 ata_id, instead of scsi_id, is the default tool now for ATA devices.
482 The configure options have changed because another library needs to be
483 installed in a different location. Instead of exec_prefix and udev_prefix,
484 libdir, rootlibdir and libexecdir are used. The Details are explained in
487 Event processes now get re-used after they handled an event. This reduces
488 the number of forks and the pressure on the CPU significantly, because
489 cloned event processes no longer cause page faults in the main daemon.
490 After the events have settled, a few worker processes stay around for
491 future events, all others get cleaned up.
493 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
494 Also inotify support is mandatory now to run udev.
496 The format of the queue exported by the udev damon has changed. There is
497 no longer a /dev/.udev/queue/ directory. The current event queue can be
498 accessed with udevadm settle and libudedv.
500 Libudev does not have the unstable API header anymore. From now on,
501 incompatible changes will be handled by bumping the library major version.
503 To build udev from the git tree gtk-doc is needed now. The tarballs will
504 build without it and contain the pre-built documentation. An online copy
506 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
508 The tools from the udev-extras repository have been merged into the main
509 udev repository. Some of the extras have larger external dependencies, and
510 they can be disabled with the configure switch --disable-extras.
516 The program vol_id and the library libvolume_id are removed from the
517 repository. Libvolume_id is merged with libblkid from the util-linux-ng
518 package. Persistent disk links for label and uuid depend on the
519 util-linux-ng version (2.15) of blkid now. Older versions of blkid
520 can not be used with udev.
522 Libudev allows to subscribe to udev events. To prevent unwanted messages
523 to be delivered, and waking up the subscribing process, a filter can be
524 installed, to drop messages inside a kernel socket filter. The filters
525 match on the <subsytem>:<devtype> properties of the device.
526 This is part of the ongoing effort to replace HAL, and switch current
527 users over to directly use libudev.
528 Libudev is still marked as experimental, and its interface might
529 eventually change if needed, but no major changes of the currently exported
530 interface are expected anymore, and a first stable release should happen
533 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
534 is not supported since while and udevd will log an error message at
535 startup. It should still be able to boot-up, but advanced rules and system
536 services which depend on the information not available in the old sysfs
537 format will fail to work correctly.
539 DVB device naming is supplied by the kernel now. In case older kernels
540 need to be supported, the old shell script should be added to a compat
547 The processed udev events get send back to the netlink socket. Libudev
548 provides access to these events. This is work-in-progress, to replace
549 the DeviceKit daemon functionality directly with libudev. There are
550 upcoming kernel changes to allow non-root users to subcribe to these
557 "udevadm settle" now optionally accepts a range of events to wait for,
558 instead of waiting for "all" events.
564 The installed watch for block device metadata changes is now removed
565 during event hadling, because some (broken) tools may be called from udev
566 rules and (wrongly) open the device with write access. After the finished
567 event handling the watch is restored.
573 Device nodes can be watched for changes with inotify with OPTIONS="watch".
574 If closed after being opened for writing, a "change" uevent will occur.
575 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
581 The udevadm test command has no longer a --force option, nodes and symlinks
582 are always updated with a test run now.
584 The udevd daemon can be started with --resolve-names=never to avoid all user
585 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
586 lookup user and groups every time events are handled.
592 We are currently merging the Ubuntu rules in the udev default rules,
593 and get one step closer to provide a common Linux /dev setup, regarding
594 device names, symlinks, and default device permissions. On udev startup,
595 we now expect the following groups to be resolvable to their ids with
597 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
598 LDAP setups need to make sure, that these groups are always resolvable at
599 bootup, with only the rootfs mounted, and without network access available.
601 Some systems may need to add some new, currently not used groups, or need
602 to add some users to new groups, but the cost of this change is minimal,
603 compared to the pain the current, rather random, differences between the
604 various distributions cause for upstream projects and third-party vendors.
606 In general, "normal" users who log into a machine should never be a member
607 of any such group, but the device-access should be managed by dynamic ACLs,
608 which get added and removed for the specific users on login/logout and
609 session activity/inactivity. These groups are only provided for custom setups,
610 and mainly system services, to allow proper privilege separation.
611 A video-streaming daemon uid would be a member of "audio" and "video", to get
612 access to the sound and video devices, but no "normal" user should ever belong
613 to the "audio" group, because he could listen to the built-in microphone with
614 any ssh-session established from the other side of the world.
616 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
617 which do not depend on the kernel device name. As usual, unique
618 devices - only a single one per product connected, or a real
619 USB serial number in the device - are always found with the same
620 name in the by-id/ directory.
621 Completely identical devices may overwrite their names in by-id/
622 and can only be found reliably in the by-path/ directory. Devices
623 specified by by-path/ must not change their connection, like the
624 USB port number they are plugged in, to keep their name.
626 To support some advanced features, Linux 2.6.22 is the oldest supported
627 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
628 supported. Older kernels should still work, and devices nodes should be
629 reliably created, but some rules and libudev will not work correctly because
630 the old kernels do not provide the expected information or interfaces.
636 Fix for a possible segfault while swapping network interface names in udev
643 The group "video" is part of the default rules now.
647 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
648 block devices in some cases. No common distro uses this option anymore,
649 and we do not get enough testing for this and recent udev versions. If
650 this option is not needed to run some old distro with a new kernel,
651 it should be disabled in the kernel config.
653 Bugfix for the $links substitution variable, which may crash if no links
654 are created. This should not happen in usual setups because we always
655 create /dev/{block,char}/ links.
657 The strings of the parsed rules, which are kept in memory, no longer
658 contain duplicate entries, or duplicate tails of strings. This, and the
659 new rules parsing/matching code reduces the total in-memory size of
660 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
663 The export of DEVTYPE=disk/partition got removed from the default
664 rules. This value is available from the kernel. The pnp shell script
665 modprobe hack is removed from the default rules. ACPI devices have _proper_
666 modalias support and take care of the same functionality.
667 Installations which support old kernels, but install current default
668 udev rules may want to add that to the compat rules file.
670 Libvolume_id now always probes for all known filesystems, and does not
671 stop at the first match. Some filesystems are marked as "exclusive probe",
672 and if any other filesytem type matches at the same time, libvolume_id
673 will, by default, not return any probing result. This is intended to prevent
674 mis-detection with conflicting left-over signatures found from earlier
675 file system formats. That way, we no longer depend on the probe-order
676 in case of multiple competing signatures. In some setups the kernel allows
677 to mount a volume with just the old filesystem signature still in place.
678 This may damage the new filesystem and cause data-loss, just by mounting
679 it. Because volume_id can not decide which one the correct signature is,
680 the wrong signatures need to be removed manually from the volume, or the
681 volume needs to be reformatted, to enable filesystem detection and possible
686 Fix segfault if compiled without optimization and dbg() does not get
687 compiled out and uses variables which are not available.
691 Bugfixes. (And maybe new bugs. :))
693 The rule matching engine got converted from a rule list to a token
694 array which reduced the in-memory rules representation of a full
695 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
696 Limits like 5 ENV and ATTR matches, and one single instance for most
697 other keys per rule are gone.
699 The NAME assignment is no longer special cased. If later rules assign
700 a NAME value again, the former value will be overwritten. As usual
701 for most other keys, the NAME value can be protected by doing a final
702 assignment with NAME:="<value>".
704 All udev code now uses libudev, which is also exported. The library
705 is still under development, marked as experimental, and its interface
706 may change as long as the DeviceKit integration is not finished.
708 Many thanks to Alan Jenkins for his continuous help, and finding and
709 optimizing some of the computing expensive parts.
715 Kernel devices and device nodes are connected now by reverse indizes in
716 /sys and /dev. A device number retrieved by a stat() or similar, the
717 kernel device directory can be found by looking up:
718 /sys/dev/{block,char}/<maj>:<min>
719 and the device node of the same device by looking up:
720 /dev/{block,char}/<maj>:<min>
724 Fix recently introduced bug, which caused a compilation without large
725 file support, where vol_id does not recognize raid signatures at the end
728 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
729 Seems some kernel versions prevent the creation of the ieee-* links,
730 so people used the scsi-* link which disappeared now.
732 More libudev work. Almost all udevadm functionality comes from libudev
735 udevadm trigger has a new option --type, which allows to trigger events
736 for "devices", for "subsystems", or "failed" devices. The old option
737 --retry-failed" still works, but is no longer mentioned in the man page.
743 The udevadm info --device-id-of-file= output has changed to use
744 the obvious format. Possible current users should use the --export
745 option which is not affected.
747 The old udev commands symlinks to udevadm are not installed, if
748 these symlinks are used, a warning is printed.
754 Optical drive's media is no longer probed for raid signatures,
755 reading the end of the device causes some devices to malfunction.
756 Also the offset of the last session found is used now to probe
759 The volume_id library got a major version number update to 1,
760 some deprecated functions are removed.
762 A shared library "libudev" gets installed now to provide access
763 to udev device information. DeviceKit, the successor of HAL, will
764 need this library to access the udev database and search sysfs for
766 The library is currently in an experimental state, also the API is
767 expected to change, as long as the DeviceKit integration is not
772 We use ./configure now. See INSTALL for details. Current
775 "/usr" - prefix for man pages, include files
777 "" - the root filesystem, prefix for libs and binaries
781 "lib" - directory name for libraries, not a path name
782 multilib 64bit systems may use "lib64" instead of "lib"
784 compile-in verbose debug messages
786 disable all logging and compile-out all log strings
788 link against SELInux libraries, to set the expected context
791 In the default rules, the group "disk" gets permissions 0660 instead
792 of 0640. One small step closer to unify distro rules. Some day, all
793 distros hopefully end up with the same set of rules.
795 No symlinks to udevadm are installed anymore, if they are still needed,
796 they should be provided by the package.
802 Default udev rules, which are not supposed to be edited by the user, should
803 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
804 the udev package and will be replaced with an update. Udev will pick up rule
806 /lib/udev/rules.d/ - default installed rules
807 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
808 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
809 It does not matter in which directory a rule file lives, all files are sorted
812 To help creating /dev/root, we have now:
813 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
816 In case the current --device-id-of-file is already used, please switch to
817 the --export format version, it saves the output parsing and the old
818 format will be changed to use ':' as a separator, like the format in the
823 Fix cdrom_id to properly recognize blank media.
829 Tape drive id-data is queried from /dev/bsg/* instead of the tape
830 nodes. This avoids rewinding tapes on open().
836 The symlinks udevcontrol and udevtrigger are no longer installed by
839 The scsi_id program does not depend on sysfs anymore. It can speak
840 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
841 data, which should solve some old problems with tape devices, where
842 we better do not open all tape device nodes to identify the device.
848 The cdrom_id program is replaced by an advanced version, which can
849 detect most common device types, and also properties of the inserted
850 media. This is part of moving some basic functionality from HAL into
851 udev (and the kernel).
857 The last WAIT_FOR_SYSFS rule is removed from the default rules.
859 The symlinks to udevadm for the debugging tools: udevmonitor and
860 udevtest are no longer created.
862 The symlinks to the udevadm man page for the old tool names are
865 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
866 should be prefixed with '@' to indicate that the path is not a
877 Udevstart is removed from the tree, it did not get installed for
878 a long time now, and is long replaced by trigger and settle.
884 All udev tools are merged into a single binary called udevadm.
885 The old names of the tools are built-in commands in udevadm now.
886 Symlinks to udevadm, with the names of the old tools, provide
887 the same functionality as the standalone tools. There is also
888 only a single udevadm.8 man page left for all tools.
890 Tools like mkinitramfs should be checked, if they need to include
891 udevadm in the list of files.
901 The etc/udev/rules.d/ directory now contains a default set of basic
902 udev rules. This initial version is the result of a rules file merge
903 of Fedora and openSUSE. For these both distros only a few specific
904 rules are left in their own file, named after the distro. Rules which
905 are optionally installed, because they are only valid for a specific
906 architecture, or rules for subsystems which are not always used are
907 in etc/udev/packages/.
913 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
914 actions by dynamically created rules.
916 SYMLINK=="<value>" matches agains the entries in the list of
917 currently defined symlinks. The links are not created in the
918 filesystem at that point in time, but the values can be matched.
920 RUN{ignore_error}+="<program>" will ignore any exit code from the
921 program and not record as a failed event.
927 Final merge of patches/features from the Ubuntu package.
933 Control characters in filesystem label strings are no longer silenty
934 removed, but hex-encoded, to be able to uniquely identify the device
935 by its symlink in /dev/disk/by-label/.
936 If libvolume_id is used by mount(8), LABEL= will work as expected,
937 if slashes or other characters are used in the label string.
939 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
940 can be specified now. The TEST key accepts an optional mode mask
941 TEST{0100}=="<is executable file>".
943 Scsi_id now supports a mode without expecting scsi-specific sysfs
944 entries to allow the extraction of cciss-device persistent properties.
950 In the future, we may see uuid's which are just simple character
951 strings (see the DDF Raid Specification). For that reason vol_id now
952 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
953 the creation of symlinks, the *_SAFE values ensure, that no control
954 or whitespace characters are used in the filename.
956 Possible users of libvolume_id, please use the volume_id_get_* functions.
957 The public struct will go away in a future release of the library.
963 Removal of useless extras/eventrecorder.sh.
973 The directory multiplexer for dev.d/ and hotplug.d are finally removed
974 from the udev package.
980 Symlinks can have priorities now, the priority is assigned to the device
981 and specified with OPTIONS="link_priority=100". Devices with higher
982 priorities overwrite the symlinks of devices with lower priorities.
983 If the device that currently owns the link, goes away, the symlink
984 will be removed, and recreated, pointing to the next device with the
985 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
986 more reliable, if multiple devices contain the same metadata and overwrite
989 The dasd_id program is removed from the udev tree, and dasdinfo, with the
990 needed rules, are part of the s390-tools now.
992 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
993 we may get the scsi sysfs mess fixed some day, and this will only catch
994 the devices we are looking for.
996 USB serial numbers for storage devices have the target:lun now appended,
997 to make it possibble to distinguish broken multi-lun devices with all
998 the same SCSI identifiers.
1000 Note: The extra "run_directory" which searches and executes stuff in
1001 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
1002 with the next release. Make sure, that you don't use it anymore, or
1003 provides your own implementation of that inefficient stuff.
1004 We are tired of reports about a "slow udev", because these directories
1005 contain stuff, that runs with _every_ event, instead of using rules,
1006 that run programs only for the matching events.
1016 DRIVER== will match only for devices that actually have a real
1017 driver. DRIVERS== must be used, if parent devices should be
1018 included in the match.
1020 Libvolume_id's "linux_raid" detection needed another fix.
1028 Add additional check to volume_id detection of via_raid, cause
1029 some company decided to put a matching pattern all over the empty
1030 storage area of their music players.
1034 Fix path_id for SAS devices.
1038 The udev daemon can be started with --debug-trace now, which will
1039 execute all events serialized to get a chance to catch a possible
1040 action that crashes the box.
1042 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1043 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1044 are excluded from the warning. Referencing parent attributes directly
1045 may break when something in the kernel driver model changes. Udev will
1046 just find the attribute by walking up the parent chain.
1048 Udevtrigger now sorts the list of devices depending on the device
1049 dependency, so a "usb" device is triggered after the parent "pci"
1054 Revert persistent-storage ata-serial '_' '-' replacement.
1060 Udevtrigger can now filter the list of devices to be triggered. Matches
1061 for subsystems or sysfs attributes can be specified.
1063 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1064 zero-sized files to avoid pointing to /sys and confuse broken tools which
1065 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1068 The rules and scripts to create udev rules for persistent network
1069 devices and optical drives are in the extras/rules_generator directory
1070 now. If you use something similar, please consider replacing your own
1071 version with this, to share the support effort. The rule_generator
1072 installs its own rules into /etc/udev/rules.d.
1074 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1075 the rule_generator depends on cdrom_id to be called in an earlier rule.
1081 Renaming of some key names (the old names still work):
1082 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1083 (The behavior of the key DRIVER will change soon in one of the next
1084 releases, to match only the event device, please switch to DRIVERS
1085 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1087 With the new key names, we have a more consistent and simpler scheme.
1088 We can match the properties of the event device only, with: KERNEL,
1089 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1090 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1091 longer mentioned in the man page and should be switched in the rule
1094 ATTR{file}="value" can be used now, to write to a sysfs file of the
1095 event device. Instead of:
1096 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1098 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1100 All the PHYSDEV* keys are deprecated and will be removed from a
1102 PHYDEVPATH - is the path of a parent device and should not be
1104 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1105 matched with SUBSYSTEMS==
1106 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1107 Newer kernels will have DRIVER in the environment,
1108 for older kernels udev puts in. Class device will
1109 no longer carry this property of a parent and
1110 DRIVERS== can be used to match such a parent value.
1111 Note that ENV{DRIVER} is only available for a few bus devices, where
1112 the driver is already bound at device event time. On coldplug, the
1113 events for a lot devices are already bound to a driver, and they will have
1114 that value set. But on hotplug, at the time the kernel creates the device,
1115 it can't know what driver may claim the device after that, therefore
1116 in most cases it will be empty.
1118 Failed events should now be re-triggered with:
1119 udevtrigger --retry-failed.
1120 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1121 files private to the udev tools. We may need to switch the current symlink
1122 target, cause some obviously broken tools try to scan all files in /dev
1123 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1124 million times. This takes ages on slow boxes.
1126 The udevinfo attribute walk (-a) now works with giving a device node
1127 name (-n) instead of a devpath (-p). The query now always works, also when
1128 no database file was created by udev.
1130 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1131 getpwnam() and getgrnam() now. One of the next releases will depend on
1132 fnmatch() and may use getopt_long().
1136 Bugfixes and small improvements.
1140 Fix path_id for recent kernels.
1146 Added support for swapping network interface names, by temporarily
1147 renaming the device and wait for the target name to become free.
1151 The built-in MODALIAS key and substitution is removed.
1155 The binary firmware helper is replaced by the usual simple
1156 shell script. Udevsend is removed from the tree.
1164 Some more keys require the correct use of '==' and '=' depending
1165 on the kind of operation beeing an assignment or a match. Rules
1166 with invalid operations are skipped and logged to syslog. Please
1167 test with udevtest if the parsing of your rules throws errors and
1168 fix possibly broken rules.
1172 Provide "udevsettle" to wait for all current udev events to finish.
1173 It also watches the current kernel netlink queue by comparing the
1174 even sequence number to make sure that there are no current pending
1175 events that have not already arrived in the daemon.
1179 Fix rule to skip persistent rules for removable IDE devices, which
1180 also skipped optical IDE drives.
1182 All *_id program are installed in /lib/udev/ by default now.
1184 No binary is stripped anymore as this should be done in the
1185 packaging process and not at build time.
1187 libvolume_id is provided as a shared library now and vol_id is
1188 linked against it. Also one of the next HAL versions will require
1189 this library, and the HAL build process will also require the
1190 header file to be installed. The copy of the same code in HAL will
1191 be removed to have only a single copy left on the system.
1195 Add persistent links for SCSI tapes. The rules file is renamed
1196 to 60-persistent-storage.rules.
1198 Create persistent path for usb devices. Can be used for all sorts
1199 of devices that can't be distinguished by other properties like
1200 multiple identical keyboards and mice connected to the same box.
1202 Provide "udevtrigger" program to request events on coldplug. The
1203 shell script is much too slow with thousends of devices.
1207 Fix persistent disk rules to exclude removable IDE drives.
1209 Warn if %e, $modalias or MODALIAS is used.
1213 Fix queue export, which wasn't correct for subsequent add/remove
1214 events for the same device.
1218 Fix cramfs detection on big endian.
1220 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1225 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1226 attributes were only checked at the parent device that matched the
1227 by BUS requested subsystem. Fix it to also look at the device we
1228 received the event for.
1230 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1235 Fix a bug where NAME="" would prevent RUN from beeing executed.
1237 RUN="/bin/program" does not longer automatically add the subsystem
1238 as the first parameter. This is from the days of /sbin/hotplug
1239 which is dead now and it's just confusing to need to add a space at
1240 the end of the program name to prevent this.
1241 If you use rules that need the subsystem as the first parameter,
1242 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1243 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1247 The udev man page has moved to udev(7) as it does not describe a command
1248 anymore. The programs udev, udevstart and udevsend are no longer installed
1249 by default and must be copied manually, if they should be installed or
1250 included in a package.
1252 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1253 the ignore rule was applied.
1255 More preparation for future sysfs changes. usb_id and scsi_id no longer
1256 depend on a magic order of devices in the /devices chain. Specific devices
1257 should be requested by their subsytem.
1259 This will always find the scsi parent device without depending on a specific
1261 dev = sysfs_device_get(devpath);
1262 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1264 The "device" link in the current sysfs layout will be automatically
1265 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1266 parent in the devpath. If a device is requested by it's symlink, like all
1267 class devices in the new sysfs layout will look like, it gets automatically
1268 resolved and substituted with the real devpath and not the symlink path.
1271 A similar logic must be applied to _all_ sysfs users, including
1272 scripts, that search along parent devices in sysfs. The explicit use of
1273 the "device" link must be avoided. With the future sysfs layout all
1274 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1275 back to the "class" or the "bus". The layout of the parent devices in
1276 /devices is not necessarily expected to be stable across kernel releases and
1277 searching for parents by their subsystem should make sysfs users tolerant
1278 for changed parent chains.
1282 Prepare udev to work with the experimental kernel patch, that moves
1283 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1285 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1286 moving the class devices to /sys/devices.
1288 Thanks again to Marco for help finding a hopefully nice compromise
1289 to make %b simpler and working again.
1293 Complete removal of libsysfs, replaced by simple helper functions
1294 which are much simpler and a bit faster. The udev daemon operatesentirely
1295 on event parameters and does not use sysfs for simple rules anymore.
1296 Please report any new bugs/problems, that may be caused by this big
1297 change. They will be fixed immediately.
1299 The enumeration format character '%e' is deprecated and will be
1300 removed sometimes from a future udev version. It never worked correctly
1301 outside of udevstart, so we can't use it with the new parallel
1302 coldplug. A simple enumeration is as useless as the devfs naming
1303 scheme, just get rid of both if you still use it.
1305 MODALIAS and $modalias is not needed and will be removed from one of
1306 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1307 the sysfs "modalias" value.
1309 Thanks a lot to Marco for all his help on finding and fixing bugs.
1313 Let scsi_id request libata drive serial numbers from page 0x80.
1315 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1316 added /dev/disk/by-name/* for device mapper device names.
1318 Removed %e from the man page. It never worked reliably outside
1319 of udevstart and udevstart is no longer recommended to use.
1323 Symlinks are now exported to the event environment. Hopefully it's no
1324 longer needed to run udevinfo from an event process, like it was
1325 mentioned on the hotplug list:
1326 UDEV [1134776873.702967] add@/block/sdb
1329 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1333 Fix a problem if udevsend is used as the hotplug handler and tries to use
1334 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1335 and this kind of problems will hopefully go away soon.
1339 All built-in logic to work around bad sysfs timing is removed with this
1340 version. The need to wait for sysfs files is almost fixed with a kernel
1341 version that doesn't work with this udev version anyway. Until we fix
1342 the timing of the "bus" link creation, the former integrated logic should
1343 be emulated by a rule placed before all other rules:
1344 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1346 The option "udev_db" does no longer exist. All udev state will be in
1347 /$udev_root/.udev/ now, there is no longer an option to set this
1349 If the init script or something else used this value, just depend on
1350 this hardcoded path. But remember _all_content_ of this directory is
1351 still private to udev and can change at any time.
1353 Default location for rule sripts and helper programs is now: /lib/udev/.
1354 Everything that is not useful on the commandline should go into this
1355 directory. Some of the helpers in the extras folder are installed there
1356 now. The rules need to be changed, to find the helpers there.
1358 Also /lib/udev/devices is recommended as a directory where packages or
1359 the user can place real device nodes, which get copied over to /dev at
1360 every boot. This should replace the various solutions with custom config
1363 Udevsend does no longer start the udev daemon. This must be done with
1364 the init script that prepares /dev on tmpfs and creates the initial nodes,
1365 before starting the daemon.
1369 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1372 The copy of klibc is removed. A systemwide installed version of klibc
1373 should be used to build a klibc udev now.
1377 NAME="" will not create any nodes, but execute RUN keys. To completely
1378 ignore an event the OPTION "ignore_device" should be used.
1380 After removal of the reorder queue, events with a TIMEOUT can be executed
1381 without any queuing now.
1385 Fixed bug in udevd, if inotify is not available. We depend on netlink
1386 uevents now, kernels without that event source will not work with that
1387 version of udev anymore.
1391 The rule parsing happens now in the daemon once at startup, all udev
1392 event processes inherit the already parsed rules from the daemon.
1393 It is shipped with SUSE10.0 and reduces heavily the system load at
1394 startup. The option to save precompiled rules and let the udev process
1395 pick the them up is removed, as it's no longer needed.
1397 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1398 device. Libsysfs is changed to "translate" the requested link into the
1399 real device path, as it would happen with the hotplug event. Otherwise
1400 device removal and the udev database will not work.
1402 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1405 A few improvements for vol_id, the filesytem probing code.
1409 Fix a stupid typo in extras/run_directory for "make install".
1411 scsi_id creates the temporary devnode now in /dev for usage with a
1412 non-writable /tmp directory.
1414 The uevent kernel socket buffer can carry app. 50.000 events now,
1415 let's see who can break this again. :)
1417 The upcoming kernel will have a new input driver core integration.
1418 Some class devices are now symlinks to the real device. libsysfs
1419 needs a fix for this to work correctly. Udevstart of older udev
1420 versions will _not_ create these devices!
1424 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1429 A bunch of mostly trivial bugfixes. From now on no node name or
1430 symlink name can contain any character than plain whitelisted ascii
1431 characters or validated utf8 byte-streams. This is needed for the
1432 /dev/disk/by-label/* links, because we import untrusted data and
1433 export it to the filesystem.
1437 More bugfixes. If udevd was started from the kernel, we don't
1438 have stdin/stdout/stderr, which broke the forked tools in some
1443 Bugfix. udevstart event ordering was broken for a long time.
1444 The new run_program() uncovered it, because /dev/null was not
1445 available while we try to run external programs.
1446 Now udevstart should create it before we run anything.
1450 Minor bugfixes and some distro rules updates. If you don't have the
1451 persistent disk rules in /dev/disk/by-*/* on your distro, just
1452 grab it from here. :)
1456 We can use socket communication now to pass events from udev to
1458 RUN+="socket:/org/freedesktop/hal/udev_event"
1459 will pass the whole udev event to the HAL daemon without the need
1460 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1464 Mostly bugfixes and see ChangeLog.
1466 The test for the existence of an environment value should be
1468 ENV{KEY}=="*" to ENV{KEY}=="?*"
1469 because "*" will not fail anymore, if the key does not exist or
1474 Bugfixes and a few tweaks described in the ChangeLog.
1478 Mostly a Bugfix release.
1480 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1481 timing with custom rules.
1485 We changed the internal rule storage format. Our large rule files took
1486 2 MB of RAM, with the change we are down to 99kB.
1488 If the device-node has been created with default name and no symlink or
1489 options are to remenber, it is not longer stored in the udevdb. HAL will
1490 need to be updated to work correctly with that change.
1492 To overrride optimization flags, OPTFLAGS may be used now.
1500 Major changes happened with this release. The goal is to take over the
1501 complete kernel-event handling and provide a more efficient way to dispatch
1502 kernel events. Replacing most of the current shell script logic and the
1503 kernel forked helper with a netlink-daemon and a rule-based event handling.
1505 o udevd listens to netlink events now. The first valid netlink event
1506 will make udevd ignore any message from udevsend that contains a
1507 SEQNUM, to avoid duplicate events. The forked events can be disabled
1509 echo "" > /proc/sys/kernel/hotplug
1510 For full support, the broken input-subsytem needs to be fixed, not to
1511 bypass the driver core.
1513 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1514 removed from udev itself and must be emulated by calling small
1515 helper binaries provided in the extras folder:
1516 make EXTRAS=extras/run_directory/
1517 will build udev_run_devd and udev_run_hotplugd, which can be called
1518 from a rule if needed:
1519 RUN+="/sbin/udev_run_hotplugd"
1520 The recommended way to handle this is to convert all the calls from
1521 the directories to explicit udev rules and get completely rid of the
1522 multiplexing. (To catch a ttyUSB event, you now no longer need to
1523 fork and exit 300 tty script instances you are not interested in, it
1524 is just one rule that matches exactly the device.)
1526 o udev handles now _all_ events not just events for class and block
1527 devices, this way it is possible to control the complete event
1528 behavior with udev rules. Especially useful for rules like:
1529 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1531 o As used in the modalias rule, udev supports now textual
1532 substitution placeholder along with the usual format chars. This
1533 needs to be documented, for now it's only visible in udev_rules_parse.c.
1535 o The rule keys support now more operations. This is documented in the
1536 man page. It is possible to add values to list-keys like the SYMLINK
1537 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1538 Also "final"-assignments are supported by using KEY:="value", which will
1539 prevent changing the key by any later rule.
1541 o kernel 2.6.12 has the "detached_state" attribute removed from
1542 sysfs, which was used to recognize sysfs population. We switched that
1543 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1544 Running this udev version on older kernels may cause a short delay for
1547 o To provide infrastructure for persistent device naming, the id programs:
1548 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1549 to export the probed data in environment key format:
1550 pim:~ # /sbin/ata_id --export /dev/hda
1551 ID_MODEL=HTS726060M9AT00
1552 ID_SERIAL=MRH401M4G6UM9B
1553 ID_REVISION=MH4OA6BA
1555 The following rules:
1556 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1557 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1560 kay@pim:~> tree /dev/disk
1563 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1564 | `-- IBM-Memory_Key -> ../../sda
1566 | |-- swap -> ../../hda1
1567 | |-- date -> ../../sda1
1568 | `-- home -> ../../hda3
1570 |-- 2E08712B0870F2E7 -> ../../hda3
1571 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1572 |-- E845-7A89 -> ../../sda1
1573 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1575 The IMPORT= operation will import these keys in the environment and make
1576 it available for later PROGRAM= and RUN= executed programs. The keys are
1577 also stored in the udevdb and can be queried from there with one of the
1580 o A few binaries are silently added to the repository, which can be used
1581 to replay kernel events from initramfs instead of using coldplug. udevd
1582 can be instructed now to queue-up events while the stored events from
1583 initramfs are filled into the udevd-queue. This code is still under
1584 development and there is no documentation now besides the code itself.
1585 The additional binaries get compiled, but are not installed by default.
1587 o There is also a temporary fix for a performance problem where too many
1588 events happen in parallel and every event needs to parse the rules.
1589 udev can now read precompiled rules stored on disk. This is likely to be
1590 replaced by a more elegant solution in a future udev version.
1594 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1595 Fix for libsysfs not to expect this file was added.
1599 All rules are applied now, but only the first matching rule with a NAME-key
1600 will be applied. All later rules with NAME-key are completely ignored. This
1601 way system supplied symlinks or permissions gets applied to user-defined
1605 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1606 to some rules, to keep the old behavior.
1608 The rules are read on "remove"-events too. That makes is possible to match
1609 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1610 instruct udev to ignore an event (OPTIONS="ignore_device").
1611 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1613 The new RUN-key supports rule-based execution of programs after device-node
1614 handling. This is meant as a general replacement for the dev.d/-directories
1615 to give fine grained control over the execution of programs.
1617 The %s{}-sysfs format char replacement values are searched at any of the
1618 devices in the device chain now, not only at the class-device.
1620 We support log priority levels now. The value udev_log in udev.conf is used
1621 to determine what is printed to syslog. This makes it possible to
1622 run a version with compiled-in debug messages in a production environment
1623 which is sometimes needed to find a bug.
1624 It is still possible to supress the inclusion of _any_ syslog usage with
1625 USE_LOG=false to create the smallest possible binaries if needed.
1626 The configured udev_log value can be overridden with the environment variable
1631 Possible use of a system-wide klibc:
1632 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1633 will link against an external klibc and our own version will be ignored.
1637 We support an unlimited count of symlinks now.
1639 If USE_STATIC=true is passed to a glibc build, we link statically and use
1640 a built-in userdb parser to resolve user and group names.
1642 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1643 we walk up the chain of physical devices to find a match.
1645 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1646 easy to skip certain attribute matches without composing rules with weird
1647 character class negations like:
1648 KERNEL="[!s][!c][!d]*"
1649 this can now be replaced with:
1651 The current simple '=' is still supported, and should work as it does today,
1652 but existing rules should be converted if possible, to be better readable.
1654 We have new ENV{}== key now, to match against a maximum of 5 environment
1657 udevstart is its own binary again, because we don't need co carry this araound
1658 with every forked event.