3 The default install location moved from /lib/udev to /usr/lib/udev,
4 to support systems without the / vs. /usr split. --libexecdir=
5 can still be configured to install things to /lib/udev.
7 The default install location of the 'udevadm' tool moved from 'sbin'
8 to /usr/bin. --bindir= can still be configured to install it in
9 /sbin. Some tools expect udevadm in 'sbin'. A symlink to udevadm
10 in /usr/bin needs to be manually created if needed.
12 Kernel modules are now loaded directly by linking udev to 'libkmod'.
13 The /sbin/modprobe tool is no longer executed by udev.
15 The /sbin/blkid tool is no longer executed from udev rules. Udev links
16 directly to libblkid now.
18 Firmware is loaded natively by udev now, the external firmware loading
19 binary is no longer used.
21 All built-in tools can be listed and tested with 'udevadm test-builtin'.
23 The 'udevadm control --reload-rules' option has been renamed to '--reload'.
24 It reloads the kernel module configuration.
26 The systemd socket files use PassCred=yes, which requires systemd
29 The udev build system only creates a .xz tarball now.
39 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
40 and non-dracut initramfs image generators need to change the init
41 scripts. Alternatively the udev build needs to move udevd back to
42 /sbin or create a symlink in /sbin, which is not done by default.
44 The path_id, usb_id, input_id tools are built-in commands now and
45 the stand-alone tools do not exist anymore. Static lists of file in
46 initramfs generators need to be updated. For testing, the commands
47 can still be executed standalone with 'udevadm test-builtin <cmd>'.
49 The fusectl filesystem is no longer mounted directly from udev.
50 Systemd systems will take care of mounting fusectl and configfs
51 now. Non-systemd systems need to ship their own rule if they
52 need these filesystems auto-mounted.
54 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
56 The support for 'udevadm trigger --type=failed, and the
57 RUN{fail_event_on_error} attribute was removed.
59 The udev control socket is now created in /run/udev/control
60 and no longer as an abstract namespace one.
62 The rules to create persistent network interface and cdrom link
63 rules automatically in /etc/udev/rules.d/ have been disabled by
64 default. Explicit configuration will be required for these use
65 cases, udev will no longer try to write any persistent system
66 configuration from a device hotplug path.
72 The udev-acl extra is no longer enabled by default now. To enable it,
73 --enable-udev_acl needs to be given at ./configure time. On systemd
74 systems, the udev-acl rules prevent it from running as the functionality
81 Udev now enables kernel media-presence polling if available. Part
82 of udisks optical drive tray-handling moved to cdrom_id: The tray
83 is locked as soon as a media is detected to enable the receiving
84 of media-eject-request events. Media-eject-request events will
87 Libudev enumerate is now able to enumerate a subtree of a given
90 The mobile-action-modeswitch modeswitch tool was deleted. The
91 functionality is provided by usb_modeswitch now.
97 The systemd service files require systemd version 28. The systemd
98 socket activation make it possible now to start 'udevd' and 'udevadm
103 Fix bug in control message handling, which can lead to a failing
104 udevadm control --exit. Thanks to Jürg Billeter for help tracking
111 We require at least Linux kernel 2.6.32 now. Some platforms might
112 require a later kernel that supports accept4() and similar, or
113 need to backport the trivial syscall wiring to the older kernels.
115 The hid2hci tool moved to the bluez package and was removed.
117 Many of the extras can be --enable/--disabled at ./configure
118 time. The --disable-extras option was removed. Some extras have
119 been disabled by default. The current options and their defaults
120 can be checked with './configure --help'.
126 Udev logs a warning now if /run is not writable at udevd
127 startup. It will still fall back to /dev/.udev, but this is
128 now considered a bug.
130 The running udev daemon can now cleanly shut down with:
131 udevadm control --exit
133 Udev in initramfs should clean the state of the udev database
134 with: udevadm info --cleanup-db which will remove all state left
135 behind from events/rules in initramfs. If initramfs uses
136 --cleanup-db and device-mapper/LVM, the rules in initramfs need
137 to add OPTIONS+="db_persist" for all dm devices. This will
138 prevent removal of the udev database for these devices.
140 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
141 120 seconds per process. If that timeout is reached the spawned
142 process will be killed. The event timeout can be overwritten with
145 If systemd is used, udev gets now activated by netlink data.
146 Systemd will bind the netlink socket which will buffer all data.
147 If needed, such setup allows a seemless update of the udev daemon,
148 where no event can be lost during a udevd update/restart.
149 Packages need to make sure to: systemctl stop udev.socket udev.service
150 or 'mask' udev.service during the upgrade to prevent any unwanted
151 auto-spawning of udevd.
152 This version of udev conflicts with systemd version below 25. The
153 unchanged service files will not wirk correctly.
159 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
160 /run mountpoint is supposed to be a tmpfs mounted during early boot,
161 available and writable to for all tools at any time during bootup,
162 it replaces /var/run/, which should become a symlink some day.
164 If /run does not exist, or is not writable, udev will fall back using
167 On systemd systems with initramfs and LVM used, packagers must
168 make sure, that the systemd and initramfs versions match. The initramfs
169 needs to create the /run mountpoint for udev to store the data, and
170 mount this tmpfs to /run in the rootfs, so the that the udev database
171 is preserved for the udev version started in the rootfs.
173 The command 'udevadm info --convert-db' is gone. The udev daemon
174 itself, at startup, converts any old database version if necessary.
176 The systemd services files have been reorganized. The udev control
177 socket is bound by systemd and passed to the started udev daemon.
178 The udev-settle.service is no longer active by default. Services which
179 can not handle hotplug setups properly need to actively pull it in, to
180 act like a barrier. Alternatively the settle service can be unconditionally
181 'systemctl'enabled, and act like a barrier for basic.target.
183 The fstab_import callout is no longer built or installed. Udev
184 should not be used to mount, does not watch changes to fstab, and
185 should not mirror fstab values in the udev database.
191 New and updated keymaps.
197 The udev database has changed, After installation of a new udev
198 version, 'udevadm info --convert-db' should be called, to let the new
199 udev/libudev version read the already stored data.
201 udevadm now supports quoting of property values, and prefixing of
203 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
206 MY_DEVNAME='/dev/sda'
210 libudev now supports:
211 udev_device_get_is_initialized()
212 udev_enumerate_add_match_is_initialized()
213 to be able to skip devices the kernel has created , but udev has
216 libudev now supports:
217 udev_device_get_usec_since_initialized()
218 to retrieve the "age" of a udev device record.
220 GUdev supports a more generic GUdevEnumerator class, udev TAG
221 handling, device initialization and timestamp now.
223 The counterpart of /sys/dev/{char,block}/$major:$minor,
224 /dev/{char,block}/$major:$minor symlinks are now unconditionally
225 created, even when no rule files exist.
227 New and updated keymaps.
233 GUdev moved from /usr to /.
243 Persistent network naming rules are disabled inside of Qemu/KVM now.
245 New and updated keymaps.
247 Udev gets unconditionally enabled on systemd installations now. There
248 is no longer the need to to run 'systemctl enable udev.service'.
262 New and fixed keymaps.
264 Install systemd service files if applicable.
270 All distribution specific rules are removed from the udev source tree,
271 most of them are no longer needed. The Gentoo rules which allow to support
272 older kernel versions, which are not covered by the default rules anymore
273 has moved to rules/misc/30-kernel-compat.rules.
279 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
280 was removed from udevd.
282 Udevd now checks the kernel commandline for the following variables:
283 udev.log-priority=<syslog priority>
284 udev.children-max=<maximum number of workers>
285 udev.exec-delay=<seconds to delay the execution of RUN=>
286 to help debuging coldplug setups where the loading of a kernel
287 module crashes the system.
289 The subdirectory in the source tree rules/packages has been renamed to
290 rules/arch, anc contains only architecture specific rules now.
300 Now the udev daemon itself, does on startup:
301 - copy the content of /lib/udev/devices to /dev
302 - create the standard symlinks like /dev/std{in,out,err},
303 /dev/core, /dev/fd, ...
304 - use static node information provided by kernel modules
305 and creates these nodes to allow module on-demand loading
306 - possibly apply permissions to all ststic nodes from udev
307 rules which are annotated to match a static node
309 The default mode for a device node is 0600 now to match the kernel
310 created devtmpfs defaults. If GROUP= is specified and no MODE= is
311 given the default will be 0660.
317 Udev now gradually starts to pass control over the primary device nodes
318 and their names to the kernel, and will in the end only manage the
319 permissions of the node, and possibly create additional symlinks.
320 As a first step NAME="" will be ignored, and NAME= setings with names
321 other than the kernel provided name will result in a logged warning.
322 Kernels that don't provide device names, or devtmpfs is not used, will
323 still work as they did before, but it is strongly recommended to use
324 only the same names for the primary device node as the recent kernel
325 provides for all devices.
329 Fix broken firmware loader search path.
335 "udevadm trigger" defaults to "change" events now instead of "add"
336 events. The "udev boot script" might need to add "--action=add" to
337 the trigger command if not already there, in case the initial coldplug
338 events are expected as "add" events.
340 The option "all_partitons" was removed from udev. This should not be
341 needed for usual hardware. Udev can not safely make assumptions
342 about non-existing partition major/minor numbers, and therefore no
343 longer provide this unreliable and unsafe option.
345 The option "ignore_remove" was removed from udev. With devtmpfs
346 udev passed control over device nodes to the kernel. This option
347 should not be needed, or can not work as advertised. Neither
348 udev nor the kernel will remove device nodes which are copied from
349 the /lib/udev/devices/ directory.
351 All "add|change" matches are replaced by "!remove" in the rules and
352 in the udev logic. All types of events will update possible symlinks
353 and permissions, only "remove" is handled special now.
355 The modem modeswitch extra was removed and the external usb_modeswitch
356 program should be used instead.
358 New and fixed keymaps.
368 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
369 depend on the current sysfs layout and the information not available in the
370 deprecated layout. All remaining support for the deprecated sysfs layout is
375 Fix for a possible endless loop in the new input_id program.
381 The option "ignore_device" does no longer exist. There is no way to
382 ignore an event, as libudev events can not be suppressed by rules.
383 It only prevented RUN keys from being executed, which results in an
384 inconsistent behavior in current setups.
386 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
387 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
390 The support for the deprecated IDE devices has been removed from the
391 default set of rules. Distros who still care about non-libata drivers
392 need to add the rules to the compat rules file.
394 The ID_CLASS property on input devices has been replaced by the more accurate
395 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
396 determined by the new "input_id" prober now. Some devices, such as touchpads,
397 can have several classes. So if you previously had custom udev rules which e. g.
398 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
399 ENV{ID_INPUT_KEYBOARD}=="?*".
405 To support DEVPATH strings larger than the maximum file name length, the
406 private udev database format has changed. If some software still reads the
407 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
408 Please do not port anything to the new format again, everything in /dev/.udev
409 is and always was private to udev, and may and will change any time without
412 Multiple devices claiming the same names in /dev are limited to symlinks
413 only now. Mixing identical symlink names and node names is not supported.
414 This reduces the amount of data in the database significantly.
416 NAME="%k" causes a warning now. It's is and always was completely superfluous.
417 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
420 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
421 if they are not the default. To support older kernels, the NAME= rules need to
422 be added to the compat rules file.
424 Symlinks to udevadm with the old command names are no longer resolved to
425 the udevadm commands.
427 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
430 The option "last_rule" does no longer exist. Its use breaks too many
431 things which expect to be run from independent later rules, and is an idication
432 that something needs to be fixed properly instead.
434 The gudev API is no longer marked as experimental,
435 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
436 is enabled by default now. Various projects already depend on introspection
437 information to bind dynamic languages to the gudev interfaces.
443 The udevadm trigger "--retry-failed" option, which is replaced since quite
444 a while by "--type=failed" is removed.
446 The failed tracking was not working at all for a few releases. The RUN
447 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
448 default is not to track any failing RUN executions.
450 New keymaps, new modem, hid2hci updated.
454 Fix possible crash in udevd when worker processes are busy, rules are
455 changed at the same time, and workers get killed to reload the rules.
461 Properties set with ENV{.FOO}="bar" are marked private by starting the
462 name with a '.'. They will not be stored in the database, and not be
463 exported with the event.
465 Firmware files are looked up in:
466 /lib/firmware/updates/$(uname -r)
467 /lib/firmware/updates
468 /lib/firmware/$(uname -r)
472 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
473 ata_id, instead of scsi_id, is the default tool now for ATA devices.
479 The configure options have changed because another library needs to be
480 installed in a different location. Instead of exec_prefix and udev_prefix,
481 libdir, rootlibdir and libexecdir are used. The Details are explained in
484 Event processes now get re-used after they handled an event. This reduces
485 the number of forks and the pressure on the CPU significantly, because
486 cloned event processes no longer cause page faults in the main daemon.
487 After the events have settled, a few worker processes stay around for
488 future events, all others get cleaned up.
490 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
491 Also inotify support is mandatory now to run udev.
493 The format of the queue exported by the udev damon has changed. There is
494 no longer a /dev/.udev/queue/ directory. The current event queue can be
495 accessed with udevadm settle and libudedv.
497 Libudev does not have the unstable API header anymore. From now on,
498 incompatible changes will be handled by bumping the library major version.
500 To build udev from the git tree gtk-doc is needed now. The tarballs will
501 build without it and contain the pre-built documentation. An online copy
503 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
505 The tools from the udev-extras repository have been merged into the main
506 udev repository. Some of the extras have larger external dependencies, and
507 they can be disabled with the configure switch --disable-extras.
513 The program vol_id and the library libvolume_id are removed from the
514 repository. Libvolume_id is merged with libblkid from the util-linux-ng
515 package. Persistent disk links for label and uuid depend on the
516 util-linux-ng version (2.15) of blkid now. Older versions of blkid
517 can not be used with udev.
519 Libudev allows to subscribe to udev events. To prevent unwanted messages
520 to be delivered, and waking up the subscribing process, a filter can be
521 installed, to drop messages inside a kernel socket filter. The filters
522 match on the <subsytem>:<devtype> properties of the device.
523 This is part of the ongoing effort to replace HAL, and switch current
524 users over to directly use libudev.
525 Libudev is still marked as experimental, and its interface might
526 eventually change if needed, but no major changes of the currently exported
527 interface are expected anymore, and a first stable release should happen
530 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
531 is not supported since while and udevd will log an error message at
532 startup. It should still be able to boot-up, but advanced rules and system
533 services which depend on the information not available in the old sysfs
534 format will fail to work correctly.
536 DVB device naming is supplied by the kernel now. In case older kernels
537 need to be supported, the old shell script should be added to a compat
544 The processed udev events get send back to the netlink socket. Libudev
545 provides access to these events. This is work-in-progress, to replace
546 the DeviceKit daemon functionality directly with libudev. There are
547 upcoming kernel changes to allow non-root users to subcribe to these
554 "udevadm settle" now optionally accepts a range of events to wait for,
555 instead of waiting for "all" events.
561 The installed watch for block device metadata changes is now removed
562 during event hadling, because some (broken) tools may be called from udev
563 rules and (wrongly) open the device with write access. After the finished
564 event handling the watch is restored.
570 Device nodes can be watched for changes with inotify with OPTIONS="watch".
571 If closed after being opened for writing, a "change" uevent will occur.
572 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
578 The udevadm test command has no longer a --force option, nodes and symlinks
579 are always updated with a test run now.
581 The udevd daemon can be started with --resolve-names=never to avoid all user
582 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
583 lookup user and groups every time events are handled.
589 We are currently merging the Ubuntu rules in the udev default rules,
590 and get one step closer to provide a common Linux /dev setup, regarding
591 device names, symlinks, and default device permissions. On udev startup,
592 we now expect the following groups to be resolvable to their ids with
594 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
595 LDAP setups need to make sure, that these groups are always resolvable at
596 bootup, with only the rootfs mounted, and without network access available.
598 Some systems may need to add some new, currently not used groups, or need
599 to add some users to new groups, but the cost of this change is minimal,
600 compared to the pain the current, rather random, differences between the
601 various distributions cause for upstream projects and third-party vendors.
603 In general, "normal" users who log into a machine should never be a member
604 of any such group, but the device-access should be managed by dynamic ACLs,
605 which get added and removed for the specific users on login/logout and
606 session activity/inactivity. These groups are only provided for custom setups,
607 and mainly system services, to allow proper privilege separation.
608 A video-streaming daemon uid would be a member of "audio" and "video", to get
609 access to the sound and video devices, but no "normal" user should ever belong
610 to the "audio" group, because he could listen to the built-in microphone with
611 any ssh-session established from the other side of the world.
613 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
614 which do not depend on the kernel device name. As usual, unique
615 devices - only a single one per product connected, or a real
616 USB serial number in the device - are always found with the same
617 name in the by-id/ directory.
618 Completely identical devices may overwrite their names in by-id/
619 and can only be found reliably in the by-path/ directory. Devices
620 specified by by-path/ must not change their connection, like the
621 USB port number they are plugged in, to keep their name.
623 To support some advanced features, Linux 2.6.22 is the oldest supported
624 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
625 supported. Older kernels should still work, and devices nodes should be
626 reliably created, but some rules and libudev will not work correctly because
627 the old kernels do not provide the expected information or interfaces.
633 Fix for a possible segfault while swapping network interface names in udev
640 The group "video" is part of the default rules now.
644 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
645 block devices in some cases. No common distro uses this option anymore,
646 and we do not get enough testing for this and recent udev versions. If
647 this option is not needed to run some old distro with a new kernel,
648 it should be disabled in the kernel config.
650 Bugfix for the $links substitution variable, which may crash if no links
651 are created. This should not happen in usual setups because we always
652 create /dev/{block,char}/ links.
654 The strings of the parsed rules, which are kept in memory, no longer
655 contain duplicate entries, or duplicate tails of strings. This, and the
656 new rules parsing/matching code reduces the total in-memory size of
657 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
660 The export of DEVTYPE=disk/partition got removed from the default
661 rules. This value is available from the kernel. The pnp shell script
662 modprobe hack is removed from the default rules. ACPI devices have _proper_
663 modalias support and take care of the same functionality.
664 Installations which support old kernels, but install current default
665 udev rules may want to add that to the compat rules file.
667 Libvolume_id now always probes for all known filesystems, and does not
668 stop at the first match. Some filesystems are marked as "exclusive probe",
669 and if any other filesytem type matches at the same time, libvolume_id
670 will, by default, not return any probing result. This is intended to prevent
671 mis-detection with conflicting left-over signatures found from earlier
672 file system formats. That way, we no longer depend on the probe-order
673 in case of multiple competing signatures. In some setups the kernel allows
674 to mount a volume with just the old filesystem signature still in place.
675 This may damage the new filesystem and cause data-loss, just by mounting
676 it. Because volume_id can not decide which one the correct signature is,
677 the wrong signatures need to be removed manually from the volume, or the
678 volume needs to be reformatted, to enable filesystem detection and possible
683 Fix segfault if compiled without optimization and dbg() does not get
684 compiled out and uses variables which are not available.
688 Bugfixes. (And maybe new bugs. :))
690 The rule matching engine got converted from a rule list to a token
691 array which reduced the in-memory rules representation of a full
692 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
693 Limits like 5 ENV and ATTR matches, and one single instance for most
694 other keys per rule are gone.
696 The NAME assignment is no longer special cased. If later rules assign
697 a NAME value again, the former value will be overwritten. As usual
698 for most other keys, the NAME value can be protected by doing a final
699 assignment with NAME:="<value>".
701 All udev code now uses libudev, which is also exported. The library
702 is still under development, marked as experimental, and its interface
703 may change as long as the DeviceKit integration is not finished.
705 Many thanks to Alan Jenkins for his continuous help, and finding and
706 optimizing some of the computing expensive parts.
712 Kernel devices and device nodes are connected now by reverse indizes in
713 /sys and /dev. A device number retrieved by a stat() or similar, the
714 kernel device directory can be found by looking up:
715 /sys/dev/{block,char}/<maj>:<min>
716 and the device node of the same device by looking up:
717 /dev/{block,char}/<maj>:<min>
721 Fix recently introduced bug, which caused a compilation without large
722 file support, where vol_id does not recognize raid signatures at the end
725 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
726 Seems some kernel versions prevent the creation of the ieee-* links,
727 so people used the scsi-* link which disappeared now.
729 More libudev work. Almost all udevadm functionality comes from libudev
732 udevadm trigger has a new option --type, which allows to trigger events
733 for "devices", for "subsystems", or "failed" devices. The old option
734 --retry-failed" still works, but is no longer mentioned in the man page.
740 The udevadm info --device-id-of-file= output has changed to use
741 the obvious format. Possible current users should use the --export
742 option which is not affected.
744 The old udev commands symlinks to udevadm are not installed, if
745 these symlinks are used, a warning is printed.
751 Optical drive's media is no longer probed for raid signatures,
752 reading the end of the device causes some devices to malfunction.
753 Also the offset of the last session found is used now to probe
756 The volume_id library got a major version number update to 1,
757 some deprecated functions are removed.
759 A shared library "libudev" gets installed now to provide access
760 to udev device information. DeviceKit, the successor of HAL, will
761 need this library to access the udev database and search sysfs for
763 The library is currently in an experimental state, also the API is
764 expected to change, as long as the DeviceKit integration is not
769 We use ./configure now. See INSTALL for details. Current
772 "/usr" - prefix for man pages, include files
774 "" - the root filesystem, prefix for libs and binaries
778 "lib" - directory name for libraries, not a path name
779 multilib 64bit systems may use "lib64" instead of "lib"
781 compile-in verbose debug messages
783 disable all logging and compile-out all log strings
785 link against SELInux libraries, to set the expected context
788 In the default rules, the group "disk" gets permissions 0660 instead
789 of 0640. One small step closer to unify distro rules. Some day, all
790 distros hopefully end up with the same set of rules.
792 No symlinks to udevadm are installed anymore, if they are still needed,
793 they should be provided by the package.
799 Default udev rules, which are not supposed to be edited by the user, should
800 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
801 the udev package and will be replaced with an update. Udev will pick up rule
803 /lib/udev/rules.d/ - default installed rules
804 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
805 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
806 It does not matter in which directory a rule file lives, all files are sorted
809 To help creating /dev/root, we have now:
810 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
813 In case the current --device-id-of-file is already used, please switch to
814 the --export format version, it saves the output parsing and the old
815 format will be changed to use ':' as a separator, like the format in the
820 Fix cdrom_id to properly recognize blank media.
826 Tape drive id-data is queried from /dev/bsg/* instead of the tape
827 nodes. This avoids rewinding tapes on open().
833 The symlinks udevcontrol and udevtrigger are no longer installed by
836 The scsi_id program does not depend on sysfs anymore. It can speak
837 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
838 data, which should solve some old problems with tape devices, where
839 we better do not open all tape device nodes to identify the device.
845 The cdrom_id program is replaced by an advanced version, which can
846 detect most common device types, and also properties of the inserted
847 media. This is part of moving some basic functionality from HAL into
848 udev (and the kernel).
854 The last WAIT_FOR_SYSFS rule is removed from the default rules.
856 The symlinks to udevadm for the debugging tools: udevmonitor and
857 udevtest are no longer created.
859 The symlinks to the udevadm man page for the old tool names are
862 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
863 should be prefixed with '@' to indicate that the path is not a
874 Udevstart is removed from the tree, it did not get installed for
875 a long time now, and is long replaced by trigger and settle.
881 All udev tools are merged into a single binary called udevadm.
882 The old names of the tools are built-in commands in udevadm now.
883 Symlinks to udevadm, with the names of the old tools, provide
884 the same functionality as the standalone tools. There is also
885 only a single udevadm.8 man page left for all tools.
887 Tools like mkinitramfs should be checked, if they need to include
888 udevadm in the list of files.
898 The etc/udev/rules.d/ directory now contains a default set of basic
899 udev rules. This initial version is the result of a rules file merge
900 of Fedora and openSUSE. For these both distros only a few specific
901 rules are left in their own file, named after the distro. Rules which
902 are optionally installed, because they are only valid for a specific
903 architecture, or rules for subsystems which are not always used are
904 in etc/udev/packages/.
910 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
911 actions by dynamically created rules.
913 SYMLINK=="<value>" matches agains the entries in the list of
914 currently defined symlinks. The links are not created in the
915 filesystem at that point in time, but the values can be matched.
917 RUN{ignore_error}+="<program>" will ignore any exit code from the
918 program and not record as a failed event.
924 Final merge of patches/features from the Ubuntu package.
930 Control characters in filesystem label strings are no longer silenty
931 removed, but hex-encoded, to be able to uniquely identify the device
932 by its symlink in /dev/disk/by-label/.
933 If libvolume_id is used by mount(8), LABEL= will work as expected,
934 if slashes or other characters are used in the label string.
936 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
937 can be specified now. The TEST key accepts an optional mode mask
938 TEST{0100}=="<is executable file>".
940 Scsi_id now supports a mode without expecting scsi-specific sysfs
941 entries to allow the extraction of cciss-device persistent properties.
947 In the future, we may see uuid's which are just simple character
948 strings (see the DDF Raid Specification). For that reason vol_id now
949 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
950 the creation of symlinks, the *_SAFE values ensure, that no control
951 or whitespace characters are used in the filename.
953 Possible users of libvolume_id, please use the volume_id_get_* functions.
954 The public struct will go away in a future release of the library.
960 Removal of useless extras/eventrecorder.sh.
970 The directory multiplexer for dev.d/ and hotplug.d are finally removed
971 from the udev package.
977 Symlinks can have priorities now, the priority is assigned to the device
978 and specified with OPTIONS="link_priority=100". Devices with higher
979 priorities overwrite the symlinks of devices with lower priorities.
980 If the device that currently owns the link, goes away, the symlink
981 will be removed, and recreated, pointing to the next device with the
982 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
983 more reliable, if multiple devices contain the same metadata and overwrite
986 The dasd_id program is removed from the udev tree, and dasdinfo, with the
987 needed rules, are part of the s390-tools now.
989 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
990 we may get the scsi sysfs mess fixed some day, and this will only catch
991 the devices we are looking for.
993 USB serial numbers for storage devices have the target:lun now appended,
994 to make it possibble to distinguish broken multi-lun devices with all
995 the same SCSI identifiers.
997 Note: The extra "run_directory" which searches and executes stuff in
998 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
999 with the next release. Make sure, that you don't use it anymore, or
1000 provides your own implementation of that inefficient stuff.
1001 We are tired of reports about a "slow udev", because these directories
1002 contain stuff, that runs with _every_ event, instead of using rules,
1003 that run programs only for the matching events.
1013 DRIVER== will match only for devices that actually have a real
1014 driver. DRIVERS== must be used, if parent devices should be
1015 included in the match.
1017 Libvolume_id's "linux_raid" detection needed another fix.
1025 Add additional check to volume_id detection of via_raid, cause
1026 some company decided to put a matching pattern all over the empty
1027 storage area of their music players.
1031 Fix path_id for SAS devices.
1035 The udev daemon can be started with --debug-trace now, which will
1036 execute all events serialized to get a chance to catch a possible
1037 action that crashes the box.
1039 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1040 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1041 are excluded from the warning. Referencing parent attributes directly
1042 may break when something in the kernel driver model changes. Udev will
1043 just find the attribute by walking up the parent chain.
1045 Udevtrigger now sorts the list of devices depending on the device
1046 dependency, so a "usb" device is triggered after the parent "pci"
1051 Revert persistent-storage ata-serial '_' '-' replacement.
1057 Udevtrigger can now filter the list of devices to be triggered. Matches
1058 for subsystems or sysfs attributes can be specified.
1060 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1061 zero-sized files to avoid pointing to /sys and confuse broken tools which
1062 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1065 The rules and scripts to create udev rules for persistent network
1066 devices and optical drives are in the extras/rules_generator directory
1067 now. If you use something similar, please consider replacing your own
1068 version with this, to share the support effort. The rule_generator
1069 installs its own rules into /etc/udev/rules.d.
1071 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1072 the rule_generator depends on cdrom_id to be called in an earlier rule.
1078 Renaming of some key names (the old names still work):
1079 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1080 (The behavior of the key DRIVER will change soon in one of the next
1081 releases, to match only the event device, please switch to DRIVERS
1082 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1084 With the new key names, we have a more consistent and simpler scheme.
1085 We can match the properties of the event device only, with: KERNEL,
1086 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1087 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1088 longer mentioned in the man page and should be switched in the rule
1091 ATTR{file}="value" can be used now, to write to a sysfs file of the
1092 event device. Instead of:
1093 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1095 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1097 All the PHYSDEV* keys are deprecated and will be removed from a
1099 PHYDEVPATH - is the path of a parent device and should not be
1101 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1102 matched with SUBSYSTEMS==
1103 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1104 Newer kernels will have DRIVER in the environment,
1105 for older kernels udev puts in. Class device will
1106 no longer carry this property of a parent and
1107 DRIVERS== can be used to match such a parent value.
1108 Note that ENV{DRIVER} is only available for a few bus devices, where
1109 the driver is already bound at device event time. On coldplug, the
1110 events for a lot devices are already bound to a driver, and they will have
1111 that value set. But on hotplug, at the time the kernel creates the device,
1112 it can't know what driver may claim the device after that, therefore
1113 in most cases it will be empty.
1115 Failed events should now be re-triggered with:
1116 udevtrigger --retry-failed.
1117 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1118 files private to the udev tools. We may need to switch the current symlink
1119 target, cause some obviously broken tools try to scan all files in /dev
1120 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1121 million times. This takes ages on slow boxes.
1123 The udevinfo attribute walk (-a) now works with giving a device node
1124 name (-n) instead of a devpath (-p). The query now always works, also when
1125 no database file was created by udev.
1127 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1128 getpwnam() and getgrnam() now. One of the next releases will depend on
1129 fnmatch() and may use getopt_long().
1133 Bugfixes and small improvements.
1137 Fix path_id for recent kernels.
1143 Added support for swapping network interface names, by temporarily
1144 renaming the device and wait for the target name to become free.
1148 The built-in MODALIAS key and substitution is removed.
1152 The binary firmware helper is replaced by the usual simple
1153 shell script. Udevsend is removed from the tree.
1161 Some more keys require the correct use of '==' and '=' depending
1162 on the kind of operation beeing an assignment or a match. Rules
1163 with invalid operations are skipped and logged to syslog. Please
1164 test with udevtest if the parsing of your rules throws errors and
1165 fix possibly broken rules.
1169 Provide "udevsettle" to wait for all current udev events to finish.
1170 It also watches the current kernel netlink queue by comparing the
1171 even sequence number to make sure that there are no current pending
1172 events that have not already arrived in the daemon.
1176 Fix rule to skip persistent rules for removable IDE devices, which
1177 also skipped optical IDE drives.
1179 All *_id program are installed in /lib/udev/ by default now.
1181 No binary is stripped anymore as this should be done in the
1182 packaging process and not at build time.
1184 libvolume_id is provided as a shared library now and vol_id is
1185 linked against it. Also one of the next HAL versions will require
1186 this library, and the HAL build process will also require the
1187 header file to be installed. The copy of the same code in HAL will
1188 be removed to have only a single copy left on the system.
1192 Add persistent links for SCSI tapes. The rules file is renamed
1193 to 60-persistent-storage.rules.
1195 Create persistent path for usb devices. Can be used for all sorts
1196 of devices that can't be distinguished by other properties like
1197 multiple identical keyboards and mice connected to the same box.
1199 Provide "udevtrigger" program to request events on coldplug. The
1200 shell script is much too slow with thousends of devices.
1204 Fix persistent disk rules to exclude removable IDE drives.
1206 Warn if %e, $modalias or MODALIAS is used.
1210 Fix queue export, which wasn't correct for subsequent add/remove
1211 events for the same device.
1215 Fix cramfs detection on big endian.
1217 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1222 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1223 attributes were only checked at the parent device that matched the
1224 by BUS requested subsystem. Fix it to also look at the device we
1225 received the event for.
1227 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1232 Fix a bug where NAME="" would prevent RUN from beeing executed.
1234 RUN="/bin/program" does not longer automatically add the subsystem
1235 as the first parameter. This is from the days of /sbin/hotplug
1236 which is dead now and it's just confusing to need to add a space at
1237 the end of the program name to prevent this.
1238 If you use rules that need the subsystem as the first parameter,
1239 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1240 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1244 The udev man page has moved to udev(7) as it does not describe a command
1245 anymore. The programs udev, udevstart and udevsend are no longer installed
1246 by default and must be copied manually, if they should be installed or
1247 included in a package.
1249 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1250 the ignore rule was applied.
1252 More preparation for future sysfs changes. usb_id and scsi_id no longer
1253 depend on a magic order of devices in the /devices chain. Specific devices
1254 should be requested by their subsytem.
1256 This will always find the scsi parent device without depending on a specific
1258 dev = sysfs_device_get(devpath);
1259 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1261 The "device" link in the current sysfs layout will be automatically
1262 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1263 parent in the devpath. If a device is requested by it's symlink, like all
1264 class devices in the new sysfs layout will look like, it gets automatically
1265 resolved and substituted with the real devpath and not the symlink path.
1268 A similar logic must be applied to _all_ sysfs users, including
1269 scripts, that search along parent devices in sysfs. The explicit use of
1270 the "device" link must be avoided. With the future sysfs layout all
1271 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1272 back to the "class" or the "bus". The layout of the parent devices in
1273 /devices is not necessarily expected to be stable across kernel releases and
1274 searching for parents by their subsystem should make sysfs users tolerant
1275 for changed parent chains.
1279 Prepare udev to work with the experimental kernel patch, that moves
1280 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1282 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1283 moving the class devices to /sys/devices.
1285 Thanks again to Marco for help finding a hopefully nice compromise
1286 to make %b simpler and working again.
1290 Complete removal of libsysfs, replaced by simple helper functions
1291 which are much simpler and a bit faster. The udev daemon operatesentirely
1292 on event parameters and does not use sysfs for simple rules anymore.
1293 Please report any new bugs/problems, that may be caused by this big
1294 change. They will be fixed immediately.
1296 The enumeration format character '%e' is deprecated and will be
1297 removed sometimes from a future udev version. It never worked correctly
1298 outside of udevstart, so we can't use it with the new parallel
1299 coldplug. A simple enumeration is as useless as the devfs naming
1300 scheme, just get rid of both if you still use it.
1302 MODALIAS and $modalias is not needed and will be removed from one of
1303 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1304 the sysfs "modalias" value.
1306 Thanks a lot to Marco for all his help on finding and fixing bugs.
1310 Let scsi_id request libata drive serial numbers from page 0x80.
1312 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1313 added /dev/disk/by-name/* for device mapper device names.
1315 Removed %e from the man page. It never worked reliably outside
1316 of udevstart and udevstart is no longer recommended to use.
1320 Symlinks are now exported to the event environment. Hopefully it's no
1321 longer needed to run udevinfo from an event process, like it was
1322 mentioned on the hotplug list:
1323 UDEV [1134776873.702967] add@/block/sdb
1326 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1330 Fix a problem if udevsend is used as the hotplug handler and tries to use
1331 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1332 and this kind of problems will hopefully go away soon.
1336 All built-in logic to work around bad sysfs timing is removed with this
1337 version. The need to wait for sysfs files is almost fixed with a kernel
1338 version that doesn't work with this udev version anyway. Until we fix
1339 the timing of the "bus" link creation, the former integrated logic should
1340 be emulated by a rule placed before all other rules:
1341 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1343 The option "udev_db" does no longer exist. All udev state will be in
1344 /$udev_root/.udev/ now, there is no longer an option to set this
1346 If the init script or something else used this value, just depend on
1347 this hardcoded path. But remember _all_content_ of this directory is
1348 still private to udev and can change at any time.
1350 Default location for rule sripts and helper programs is now: /lib/udev/.
1351 Everything that is not useful on the commandline should go into this
1352 directory. Some of the helpers in the extras folder are installed there
1353 now. The rules need to be changed, to find the helpers there.
1355 Also /lib/udev/devices is recommended as a directory where packages or
1356 the user can place real device nodes, which get copied over to /dev at
1357 every boot. This should replace the various solutions with custom config
1360 Udevsend does no longer start the udev daemon. This must be done with
1361 the init script that prepares /dev on tmpfs and creates the initial nodes,
1362 before starting the daemon.
1366 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1369 The copy of klibc is removed. A systemwide installed version of klibc
1370 should be used to build a klibc udev now.
1374 NAME="" will not create any nodes, but execute RUN keys. To completely
1375 ignore an event the OPTION "ignore_device" should be used.
1377 After removal of the reorder queue, events with a TIMEOUT can be executed
1378 without any queuing now.
1382 Fixed bug in udevd, if inotify is not available. We depend on netlink
1383 uevents now, kernels without that event source will not work with that
1384 version of udev anymore.
1388 The rule parsing happens now in the daemon once at startup, all udev
1389 event processes inherit the already parsed rules from the daemon.
1390 It is shipped with SUSE10.0 and reduces heavily the system load at
1391 startup. The option to save precompiled rules and let the udev process
1392 pick the them up is removed, as it's no longer needed.
1394 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1395 device. Libsysfs is changed to "translate" the requested link into the
1396 real device path, as it would happen with the hotplug event. Otherwise
1397 device removal and the udev database will not work.
1399 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1402 A few improvements for vol_id, the filesytem probing code.
1406 Fix a stupid typo in extras/run_directory for "make install".
1408 scsi_id creates the temporary devnode now in /dev for usage with a
1409 non-writable /tmp directory.
1411 The uevent kernel socket buffer can carry app. 50.000 events now,
1412 let's see who can break this again. :)
1414 The upcoming kernel will have a new input driver core integration.
1415 Some class devices are now symlinks to the real device. libsysfs
1416 needs a fix for this to work correctly. Udevstart of older udev
1417 versions will _not_ create these devices!
1421 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1426 A bunch of mostly trivial bugfixes. From now on no node name or
1427 symlink name can contain any character than plain whitelisted ascii
1428 characters or validated utf8 byte-streams. This is needed for the
1429 /dev/disk/by-label/* links, because we import untrusted data and
1430 export it to the filesystem.
1434 More bugfixes. If udevd was started from the kernel, we don't
1435 have stdin/stdout/stderr, which broke the forked tools in some
1440 Bugfix. udevstart event ordering was broken for a long time.
1441 The new run_program() uncovered it, because /dev/null was not
1442 available while we try to run external programs.
1443 Now udevstart should create it before we run anything.
1447 Minor bugfixes and some distro rules updates. If you don't have the
1448 persistent disk rules in /dev/disk/by-*/* on your distro, just
1449 grab it from here. :)
1453 We can use socket communication now to pass events from udev to
1455 RUN+="socket:/org/freedesktop/hal/udev_event"
1456 will pass the whole udev event to the HAL daemon without the need
1457 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1461 Mostly bugfixes and see ChangeLog.
1463 The test for the existence of an environment value should be
1465 ENV{KEY}=="*" to ENV{KEY}=="?*"
1466 because "*" will not fail anymore, if the key does not exist or
1471 Bugfixes and a few tweaks described in the ChangeLog.
1475 Mostly a Bugfix release.
1477 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1478 timing with custom rules.
1482 We changed the internal rule storage format. Our large rule files took
1483 2 MB of RAM, with the change we are down to 99kB.
1485 If the device-node has been created with default name and no symlink or
1486 options are to remenber, it is not longer stored in the udevdb. HAL will
1487 need to be updated to work correctly with that change.
1489 To overrride optimization flags, OPTFLAGS may be used now.
1497 Major changes happened with this release. The goal is to take over the
1498 complete kernel-event handling and provide a more efficient way to dispatch
1499 kernel events. Replacing most of the current shell script logic and the
1500 kernel forked helper with a netlink-daemon and a rule-based event handling.
1502 o udevd listens to netlink events now. The first valid netlink event
1503 will make udevd ignore any message from udevsend that contains a
1504 SEQNUM, to avoid duplicate events. The forked events can be disabled
1506 echo "" > /proc/sys/kernel/hotplug
1507 For full support, the broken input-subsytem needs to be fixed, not to
1508 bypass the driver core.
1510 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1511 removed from udev itself and must be emulated by calling small
1512 helper binaries provided in the extras folder:
1513 make EXTRAS=extras/run_directory/
1514 will build udev_run_devd and udev_run_hotplugd, which can be called
1515 from a rule if needed:
1516 RUN+="/sbin/udev_run_hotplugd"
1517 The recommended way to handle this is to convert all the calls from
1518 the directories to explicit udev rules and get completely rid of the
1519 multiplexing. (To catch a ttyUSB event, you now no longer need to
1520 fork and exit 300 tty script instances you are not interested in, it
1521 is just one rule that matches exactly the device.)
1523 o udev handles now _all_ events not just events for class and block
1524 devices, this way it is possible to control the complete event
1525 behavior with udev rules. Especially useful for rules like:
1526 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1528 o As used in the modalias rule, udev supports now textual
1529 substitution placeholder along with the usual format chars. This
1530 needs to be documented, for now it's only visible in udev_rules_parse.c.
1532 o The rule keys support now more operations. This is documented in the
1533 man page. It is possible to add values to list-keys like the SYMLINK
1534 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1535 Also "final"-assignments are supported by using KEY:="value", which will
1536 prevent changing the key by any later rule.
1538 o kernel 2.6.12 has the "detached_state" attribute removed from
1539 sysfs, which was used to recognize sysfs population. We switched that
1540 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1541 Running this udev version on older kernels may cause a short delay for
1544 o To provide infrastructure for persistent device naming, the id programs:
1545 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1546 to export the probed data in environment key format:
1547 pim:~ # /sbin/ata_id --export /dev/hda
1548 ID_MODEL=HTS726060M9AT00
1549 ID_SERIAL=MRH401M4G6UM9B
1550 ID_REVISION=MH4OA6BA
1552 The following rules:
1553 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1554 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1557 kay@pim:~> tree /dev/disk
1560 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1561 | `-- IBM-Memory_Key -> ../../sda
1563 | |-- swap -> ../../hda1
1564 | |-- date -> ../../sda1
1565 | `-- home -> ../../hda3
1567 |-- 2E08712B0870F2E7 -> ../../hda3
1568 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1569 |-- E845-7A89 -> ../../sda1
1570 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1572 The IMPORT= operation will import these keys in the environment and make
1573 it available for later PROGRAM= and RUN= executed programs. The keys are
1574 also stored in the udevdb and can be queried from there with one of the
1577 o A few binaries are silently added to the repository, which can be used
1578 to replay kernel events from initramfs instead of using coldplug. udevd
1579 can be instructed now to queue-up events while the stored events from
1580 initramfs are filled into the udevd-queue. This code is still under
1581 development and there is no documentation now besides the code itself.
1582 The additional binaries get compiled, but are not installed by default.
1584 o There is also a temporary fix for a performance problem where too many
1585 events happen in parallel and every event needs to parse the rules.
1586 udev can now read precompiled rules stored on disk. This is likely to be
1587 replaced by a more elegant solution in a future udev version.
1591 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1592 Fix for libsysfs not to expect this file was added.
1596 All rules are applied now, but only the first matching rule with a NAME-key
1597 will be applied. All later rules with NAME-key are completely ignored. This
1598 way system supplied symlinks or permissions gets applied to user-defined
1602 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1603 to some rules, to keep the old behavior.
1605 The rules are read on "remove"-events too. That makes is possible to match
1606 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1607 instruct udev to ignore an event (OPTIONS="ignore_device").
1608 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1610 The new RUN-key supports rule-based execution of programs after device-node
1611 handling. This is meant as a general replacement for the dev.d/-directories
1612 to give fine grained control over the execution of programs.
1614 The %s{}-sysfs format char replacement values are searched at any of the
1615 devices in the device chain now, not only at the class-device.
1617 We support log priority levels now. The value udev_log in udev.conf is used
1618 to determine what is printed to syslog. This makes it possible to
1619 run a version with compiled-in debug messages in a production environment
1620 which is sometimes needed to find a bug.
1621 It is still possible to supress the inclusion of _any_ syslog usage with
1622 USE_LOG=false to create the smallest possible binaries if needed.
1623 The configured udev_log value can be overridden with the environment variable
1628 Possible use of a system-wide klibc:
1629 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1630 will link against an external klibc and our own version will be ignored.
1634 We support an unlimited count of symlinks now.
1636 If USE_STATIC=true is passed to a glibc build, we link statically and use
1637 a built-in userdb parser to resolve user and group names.
1639 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1640 we walk up the chain of physical devices to find a match.
1642 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1643 easy to skip certain attribute matches without composing rules with weird
1644 character class negations like:
1645 KERNEL="[!s][!c][!d]*"
1646 this can now be replaced with:
1648 The current simple '=' is still supported, and should work as it does today,
1649 but existing rules should be converted if possible, to be better readable.
1651 We have new ENV{}== key now, to match against a maximum of 5 environment
1654 udevstart is its own binary again, because we don't need co carry this araound
1655 with every forked event.