5 The path_id, usb_id, input_id tools are built-in commands now
6 and the stand-alone tools do not exist anymore. For testing,
7 the commands can be run with 'udevadm test-builtin <cmd>'.
9 The fusectl filesystem is no longer mounted directly from udev.
10 Systemd systems will take care of mounting fusectl and configfs
11 now. Non-systemd systems need to ship their own rule if they
12 need these filesystems auto-mounted.
14 The long deprecated keys: SYSFS, ID, BUS have been removed.
16 The support for 'udevadm trigger --type=failed, and the
17 RUN{fail_event_on_error} attribute was removed.
23 The udev-acl extra is no longer enabled by default now. To enable it,
24 --enable-udev_acl needs to be given at ./configure time. On systemd
25 systems, the udev-acl rules prevent it from running as the functionality
32 Udev now enables kernel media-presence polling if available. Part
33 of udisks optical drive tray-handling moved to cdrom_id: The tray
34 is locked as soon as a media is detected to enable the receiving
35 of media-eject-request events. Media-eject-request events will
38 Libudev enumerate is now able to enumerate a subtree of a given
41 The mobile-action-modeswitch modeswitch tool was deleted. The
42 functionality is provided by usb_modeswitch now.
48 The systemd service files require systemd version 28. The systemd
49 socket activation make it possible now to start 'udevd' and 'udevadm
54 Fix bug in control message handling, which can lead to a failing
55 udevadm control --exit. Thanks to Jürg Billeter for help tracking
62 We require at least Linux kernel 2.6.32 now. Some platforms might
63 require a later kernel that supports accept4() and similar, or
64 need to backport the trivial syscall wiring to the older kernels.
66 The hid2hci tool moved to the bluez package and was removed.
68 Many of the extras can be --enable/--disabled at ./configure
69 time. The --disable-extras option was removed. Some extras have
70 been disabled by default. The current options and their defaults
71 can be checked with './configure --help'.
77 Udev logs a warning now if /run is not writable at udevd
78 startup. It will still fall back to /dev/.udev, but this is
81 The running udev daemon can now cleanly shut down with:
82 udevadm control --exit
84 Udev in initramfs should clean the state of the udev database
85 with: udevadm info --cleanup-db which will remove all state left
86 behind from events/rules in initramfs. If initramfs uses
87 --cleanup-db and device-mapper/LVM, the rules in initramfs need
88 to add OPTIONS+="db_persist" for all dm devices. This will
89 prevent removal of the udev database for these devices.
91 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
92 120 seconds per process. If that timeout is reached the spawned
93 process will be killed. The event timeout can be overwritten with
96 If systemd is used, udev gets now activated by netlink data.
97 Systemd will bind the netlink socket which will buffer all data.
98 If needed, such setup allows a seemless update of the udev daemon,
99 where no event can be lost during a udevd update/restart.
100 Packages need to make sure to: systemctl stop udev.socket udev.service
101 or 'mask' udev.service during the upgrade to prevent any unwanted
102 auto-spawning of udevd.
103 This version of udev conflicts with systemd version below 25. The
104 unchanged service files will not wirk correctly.
110 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
111 /run mountpoint is supposed to be a tmpfs mounted during early boot,
112 available and writable to for all tools at any time during bootup,
113 it replaces /var/run/, which should become a symlink some day.
115 If /run does not exist, or is not writable, udev will fall back using
118 On systemd systems with initramfs and LVM used, packagers must
119 make sure, that the systemd and initramfs versions match. The initramfs
120 needs to create the /run mountpoint for udev to store the data, and
121 mount this tmpfs to /run in the rootfs, so the that the udev database
122 is preserved for the udev version started in the rootfs.
124 The command 'udevadm info --convert-db' is gone. The udev daemon
125 itself, at startup, converts any old database version if necessary.
127 The systemd services files have been reorganized. The udev control
128 socket is bound by systemd and passed to the started udev daemon.
129 The udev-settle.service is no longer active by default. Services which
130 can not handle hotplug setups properly need to actively pull it in, to
131 act like a barrier. Alternatively the settle service can be unconditionally
132 'systemctl'enabled, and act like a barrier for basic.target.
134 The fstab_import callout is no longer built or installed. Udev
135 should not be used to mount, does not watch changes to fstab, and
136 should not mirror fstab values in the udev database.
142 New and updated keymaps.
148 The udev database has changed, After installation of a new udev
149 version, 'udevadm info --convert-db' should be called, to let the new
150 udev/libudev version read the already stored data.
152 udevadm now supports quoting of property values, and prefixing of
154 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
157 MY_DEVNAME='/dev/sda'
161 libudev now supports:
162 udev_device_get_is_initialized()
163 udev_enumerate_add_match_is_initialized()
164 to be able to skip devices the kernel has created , but udev has
167 libudev now supports:
168 udev_device_get_usec_since_initialized()
169 to retrieve the "age" of a udev device record.
171 GUdev supports a more generic GUdevEnumerator class, udev TAG
172 handling, device initialization and timestamp now.
174 The counterpart of /sys/dev/{char,block}/$major:$minor,
175 /dev/{char,block}/$major:$minor symlinks are now unconditionally
176 created, even when no rule files exist.
178 New and updated keymaps.
184 GUdev moved from /usr to /.
194 Persistent network naming rules are disabled inside of Qemu/KVM now.
196 New and updated keymaps.
198 Udev gets unconditionally enabled on systemd installations now. There
199 is no longer the need to to run 'systemctl enable udev.service'.
213 New and fixed keymaps.
215 Install systemd service files if applicable.
221 All distribution specific rules are removed from the udev source tree,
222 most of them are no longer needed. The Gentoo rules which allow to support
223 older kernel versions, which are not covered by the default rules anymore
224 has moved to rules/misc/30-kernel-compat.rules.
230 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
231 was removed from udevd.
233 Udevd now checks the kernel commandline for the following variables:
234 udev.log-priority=<syslog priority>
235 udev.children-max=<maximum number of workers>
236 udev.exec-delay=<seconds to delay the execution of RUN=>
237 to help debuging coldplug setups where the loading of a kernel
238 module crashes the system.
240 The subdirectory in the source tree rules/packages has been renamed to
241 rules/arch, anc contains only architecture specific rules now.
251 Now the udev daemon itself, does on startup:
252 - copy the content of /lib/udev/devices to /dev
253 - create the standard symlinks like /dev/std{in,out,err},
254 /dev/core, /dev/fd, ...
255 - use static node information provided by kernel modules
256 and creates these nodes to allow module on-demand loading
257 - possibly apply permissions to all ststic nodes from udev
258 rules which are annotated to match a static node
260 The default mode for a device node is 0600 now to match the kernel
261 created devtmpfs defaults. If GROUP= is specified and no MODE= is
262 given the default will be 0660.
268 Udev now gradually starts to pass control over the primary device nodes
269 and their names to the kernel, and will in the end only manage the
270 permissions of the node, and possibly create additional symlinks.
271 As a first step NAME="" will be ignored, and NAME= setings with names
272 other than the kernel provided name will result in a logged warning.
273 Kernels that don't provide device names, or devtmpfs is not used, will
274 still work as they did before, but it is strongly recommended to use
275 only the same names for the primary device node as the recent kernel
276 provides for all devices.
280 Fix broken firmware loader search path.
286 "udevadm trigger" defaults to "change" events now instead of "add"
287 events. The "udev boot script" might need to add "--action=add" to
288 the trigger command if not already there, in case the initial coldplug
289 events are expected as "add" events.
291 The option "all_partitons" was removed from udev. This should not be
292 needed for usual hardware. Udev can not safely make assumptions
293 about non-existing partition major/minor numbers, and therefore no
294 longer provide this unreliable and unsafe option.
296 The option "ignore_remove" was removed from udev. With devtmpfs
297 udev passed control over device nodes to the kernel. This option
298 should not be needed, or can not work as advertised. Neither
299 udev nor the kernel will remove device nodes which are copied from
300 the /lib/udev/devices/ directory.
302 All "add|change" matches are replaced by "!remove" in the rules and
303 in the udev logic. All types of events will update possible symlinks
304 and permissions, only "remove" is handled special now.
306 The modem modeswitch extra was removed and the external usb_modeswitch
307 program should be used instead.
309 New and fixed keymaps.
319 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
320 depend on the current sysfs layout and the information not available in the
321 deprecated layout. All remaining support for the deprecated sysfs layout is
326 Fix for a possible endless loop in the new input_id program.
332 The option "ignore_device" does no longer exist. There is no way to
333 ignore an event, as libudev events can not be suppressed by rules.
334 It only prevented RUN keys from being executed, which results in an
335 inconsistent behavior in current setups.
337 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
338 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
341 The support for the deprecated IDE devices has been removed from the
342 default set of rules. Distros who still care about non-libata drivers
343 need to add the rules to the compat rules file.
345 The ID_CLASS property on input devices has been replaced by the more accurate
346 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
347 determined by the new "input_id" prober now. Some devices, such as touchpads,
348 can have several classes. So if you previously had custom udev rules which e. g.
349 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
350 ENV{ID_INPUT_KEYBOARD}=="?*".
356 To support DEVPATH strings larger than the maximum file name length, the
357 private udev database format has changed. If some software still reads the
358 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
359 Please do not port anything to the new format again, everything in /dev/.udev
360 is and always was private to udev, and may and will change any time without
363 Multiple devices claiming the same names in /dev are limited to symlinks
364 only now. Mixing identical symlink names and node names is not supported.
365 This reduces the amount of data in the database significantly.
367 NAME="%k" causes a warning now. It's is and always was completely superfluous.
368 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
371 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
372 if they are not the default. To support older kernels, the NAME= rules need to
373 be added to the compat rules file.
375 Symlinks to udevadm with the old command names are no longer resolved to
376 the udevadm commands.
378 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
381 The option "last_rule" does no longer exist. Its use breaks too many
382 things which expect to be run from independent later rules, and is an idication
383 that something needs to be fixed properly instead.
385 The gudev API is no longer marked as experimental,
386 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
387 is enabled by default now. Various projects already depend on introspection
388 information to bind dynamic languages to the gudev interfaces.
394 The udevadm trigger "--retry-failed" option, which is replaced since quite
395 a while by "--type=failed" is removed.
397 The failed tracking was not working at all for a few releases. The RUN
398 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
399 default is not to track any failing RUN executions.
401 New keymaps, new modem, hid2hci updated.
405 Fix possible crash in udevd when worker processes are busy, rules are
406 changed at the same time, and workers get killed to reload the rules.
412 Properties set with ENV{.FOO}="bar" are marked private by starting the
413 name with a '.'. They will not be stored in the database, and not be
414 exported with the event.
416 Firmware files are looked up in:
417 /lib/firmware/updates/$(uname -r)
418 /lib/firmware/updates
419 /lib/firmware/$(uname -r)
423 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
424 ata_id, instead of scsi_id, is the default tool now for ATA devices.
430 The configure options have changed because another library needs to be
431 installed in a different location. Instead of exec_prefix and udev_prefix,
432 libdir, rootlibdir and libexecdir are used. The Details are explained in
435 Event processes now get re-used after they handled an event. This reduces
436 the number of forks and the pressure on the CPU significantly, because
437 cloned event processes no longer cause page faults in the main daemon.
438 After the events have settled, a few worker processes stay around for
439 future events, all others get cleaned up.
441 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
442 Also inotify support is mandatory now to run udev.
444 The format of the queue exported by the udev damon has changed. There is
445 no longer a /dev/.udev/queue/ directory. The current event queue can be
446 accessed with udevadm settle and libudedv.
448 Libudev does not have the unstable API header anymore. From now on,
449 incompatible changes will be handled by bumping the library major version.
451 To build udev from the git tree gtk-doc is needed now. The tarballs will
452 build without it and contain the pre-built documentation. An online copy
454 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
456 The tools from the udev-extras repository have been merged into the main
457 udev repository. Some of the extras have larger external dependencies, and
458 they can be disabled with the configure switch --disable-extras.
464 The program vol_id and the library libvolume_id are removed from the
465 repository. Libvolume_id is merged with libblkid from the util-linux-ng
466 package. Persistent disk links for label and uuid depend on the
467 util-linux-ng version (2.15) of blkid now. Older versions of blkid
468 can not be used with udev.
470 Libudev allows to subscribe to udev events. To prevent unwanted messages
471 to be delivered, and waking up the subscribing process, a filter can be
472 installed, to drop messages inside a kernel socket filter. The filters
473 match on the <subsytem>:<devtype> properties of the device.
474 This is part of the ongoing effort to replace HAL, and switch current
475 users over to directly use libudev.
476 Libudev is still marked as experimental, and its interface might
477 eventually change if needed, but no major changes of the currently exported
478 interface are expected anymore, and a first stable release should happen
481 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
482 is not supported since while and udevd will log an error message at
483 startup. It should still be able to boot-up, but advanced rules and system
484 services which depend on the information not available in the old sysfs
485 format will fail to work correctly.
487 DVB device naming is supplied by the kernel now. In case older kernels
488 need to be supported, the old shell script should be added to a compat
495 The processed udev events get send back to the netlink socket. Libudev
496 provides access to these events. This is work-in-progress, to replace
497 the DeviceKit daemon functionality directly with libudev. There are
498 upcoming kernel changes to allow non-root users to subcribe to these
505 "udevadm settle" now optionally accepts a range of events to wait for,
506 instead of waiting for "all" events.
512 The installed watch for block device metadata changes is now removed
513 during event hadling, because some (broken) tools may be called from udev
514 rules and (wrongly) open the device with write access. After the finished
515 event handling the watch is restored.
521 Device nodes can be watched for changes with inotify with OPTIONS="watch".
522 If closed after being opened for writing, a "change" uevent will occur.
523 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
529 The udevadm test command has no longer a --force option, nodes and symlinks
530 are always updated with a test run now.
532 The udevd daemon can be started with --resolve-names=never to avoid all user
533 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
534 lookup user and groups every time events are handled.
540 We are currently merging the Ubuntu rules in the udev default rules,
541 and get one step closer to provide a common Linux /dev setup, regarding
542 device names, symlinks, and default device permissions. On udev startup,
543 we now expect the following groups to be resolvable to their ids with
545 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
546 LDAP setups need to make sure, that these groups are always resolvable at
547 bootup, with only the rootfs mounted, and without network access available.
549 Some systems may need to add some new, currently not used groups, or need
550 to add some users to new groups, but the cost of this change is minimal,
551 compared to the pain the current, rather random, differences between the
552 various distributions cause for upstream projects and third-party vendors.
554 In general, "normal" users who log into a machine should never be a member
555 of any such group, but the device-access should be managed by dynamic ACLs,
556 which get added and removed for the specific users on login/logout and
557 session activity/inactivity. These groups are only provided for custom setups,
558 and mainly system services, to allow proper privilege separation.
559 A video-streaming daemon uid would be a member of "audio" and "video", to get
560 access to the sound and video devices, but no "normal" user should ever belong
561 to the "audio" group, because he could listen to the built-in microphone with
562 any ssh-session established from the other side of the world.
564 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
565 which do not depend on the kernel device name. As usual, unique
566 devices - only a single one per product connected, or a real
567 USB serial number in the device - are always found with the same
568 name in the by-id/ directory.
569 Completely identical devices may overwrite their names in by-id/
570 and can only be found reliably in the by-path/ directory. Devices
571 specified by by-path/ must not change their connection, like the
572 USB port number they are plugged in, to keep their name.
574 To support some advanced features, Linux 2.6.22 is the oldest supported
575 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
576 supported. Older kernels should still work, and devices nodes should be
577 reliably created, but some rules and libudev will not work correctly because
578 the old kernels do not provide the expected information or interfaces.
584 Fix for a possible segfault while swapping network interface names in udev
591 The group "video" is part of the default rules now.
595 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
596 block devices in some cases. No common distro uses this option anymore,
597 and we do not get enough testing for this and recent udev versions. If
598 this option is not needed to run some old distro with a new kernel,
599 it should be disabled in the kernel config.
601 Bugfix for the $links substitution variable, which may crash if no links
602 are created. This should not happen in usual setups because we always
603 create /dev/{block,char}/ links.
605 The strings of the parsed rules, which are kept in memory, no longer
606 contain duplicate entries, or duplicate tails of strings. This, and the
607 new rules parsing/matching code reduces the total in-memory size of
608 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
611 The export of DEVTYPE=disk/partition got removed from the default
612 rules. This value is available from the kernel. The pnp shell script
613 modprobe hack is removed from the default rules. ACPI devices have _proper_
614 modalias support and take care of the same functionality.
615 Installations which support old kernels, but install current default
616 udev rules may want to add that to the compat rules file.
618 Libvolume_id now always probes for all known filesystems, and does not
619 stop at the first match. Some filesystems are marked as "exclusive probe",
620 and if any other filesytem type matches at the same time, libvolume_id
621 will, by default, not return any probing result. This is intended to prevent
622 mis-detection with conflicting left-over signatures found from earlier
623 file system formats. That way, we no longer depend on the probe-order
624 in case of multiple competing signatures. In some setups the kernel allows
625 to mount a volume with just the old filesystem signature still in place.
626 This may damage the new filesystem and cause data-loss, just by mounting
627 it. Because volume_id can not decide which one the correct signature is,
628 the wrong signatures need to be removed manually from the volume, or the
629 volume needs to be reformatted, to enable filesystem detection and possible
634 Fix segfault if compiled without optimization and dbg() does not get
635 compiled out and uses variables which are not available.
639 Bugfixes. (And maybe new bugs. :))
641 The rule matching engine got converted from a rule list to a token
642 array which reduced the in-memory rules representation of a full
643 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
644 Limits like 5 ENV and ATTR matches, and one single instance for most
645 other keys per rule are gone.
647 The NAME assignment is no longer special cased. If later rules assign
648 a NAME value again, the former value will be overwritten. As usual
649 for most other keys, the NAME value can be protected by doing a final
650 assignment with NAME:="<value>".
652 All udev code now uses libudev, which is also exported. The library
653 is still under development, marked as experimental, and its interface
654 may change as long as the DeviceKit integration is not finished.
656 Many thanks to Alan Jenkins for his continuous help, and finding and
657 optimizing some of the computing expensive parts.
663 Kernel devices and device nodes are connected now by reverse indizes in
664 /sys and /dev. A device number retrieved by a stat() or similar, the
665 kernel device directory can be found by looking up:
666 /sys/dev/{block,char}/<maj>:<min>
667 and the device node of the same device by looking up:
668 /dev/{block,char}/<maj>:<min>
672 Fix recently introduced bug, which caused a compilation without large
673 file support, where vol_id does not recognize raid signatures at the end
676 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
677 Seems some kernel versions prevent the creation of the ieee-* links,
678 so people used the scsi-* link which disappeared now.
680 More libudev work. Almost all udevadm functionality comes from libudev
683 udevadm trigger has a new option --type, which allows to trigger events
684 for "devices", for "subsystems", or "failed" devices. The old option
685 --retry-failed" still works, but is no longer mentioned in the man page.
691 The udevadm info --device-id-of-file= output has changed to use
692 the obvious format. Possible current users should use the --export
693 option which is not affected.
695 The old udev commands symlinks to udevadm are not installed, if
696 these symlinks are used, a warning is printed.
702 Optical drive's media is no longer probed for raid signatures,
703 reading the end of the device causes some devices to malfunction.
704 Also the offset of the last session found is used now to probe
707 The volume_id library got a major version number update to 1,
708 some deprecated functions are removed.
710 A shared library "libudev" gets installed now to provide access
711 to udev device information. DeviceKit, the successor of HAL, will
712 need this library to access the udev database and search sysfs for
714 The library is currently in an experimental state, also the API is
715 expected to change, as long as the DeviceKit integration is not
720 We use ./configure now. See INSTALL for details. Current
723 "/usr" - prefix for man pages, include files
725 "" - the root filesystem, prefix for libs and binaries
729 "lib" - directory name for libraries, not a path name
730 multilib 64bit systems may use "lib64" instead of "lib"
732 compile-in verbose debug messages
734 disable all logging and compile-out all log strings
736 link against SELInux libraries, to set the expected context
739 In the default rules, the group "disk" gets permissions 0660 instead
740 of 0640. One small step closer to unify distro rules. Some day, all
741 distros hopefully end up with the same set of rules.
743 No symlinks to udevadm are installed anymore, if they are still needed,
744 they should be provided by the package.
750 Default udev rules, which are not supposed to be edited by the user, should
751 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
752 the udev package and will be replaced with an update. Udev will pick up rule
754 /lib/udev/rules.d/ - default installed rules
755 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
756 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
757 It does not matter in which directory a rule file lives, all files are sorted
760 To help creating /dev/root, we have now:
761 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
764 In case the current --device-id-of-file is already used, please switch to
765 the --export format version, it saves the output parsing and the old
766 format will be changed to use ':' as a separator, like the format in the
771 Fix cdrom_id to properly recognize blank media.
777 Tape drive id-data is queried from /dev/bsg/* instead of the tape
778 nodes. This avoids rewinding tapes on open().
784 The symlinks udevcontrol and udevtrigger are no longer installed by
787 The scsi_id program does not depend on sysfs anymore. It can speak
788 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
789 data, which should solve some old problems with tape devices, where
790 we better do not open all tape device nodes to identify the device.
796 The cdrom_id program is replaced by an advanced version, which can
797 detect most common device types, and also properties of the inserted
798 media. This is part of moving some basic functionality from HAL into
799 udev (and the kernel).
805 The last WAIT_FOR_SYSFS rule is removed from the default rules.
807 The symlinks to udevadm for the debugging tools: udevmonitor and
808 udevtest are no longer created.
810 The symlinks to the udevadm man page for the old tool names are
813 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
814 should be prefixed with '@' to indicate that the path is not a
825 Udevstart is removed from the tree, it did not get installed for
826 a long time now, and is long replaced by trigger and settle.
832 All udev tools are merged into a single binary called udevadm.
833 The old names of the tools are built-in commands in udevadm now.
834 Symlinks to udevadm, with the names of the old tools, provide
835 the same functionality as the standalone tools. There is also
836 only a single udevadm.8 man page left for all tools.
838 Tools like mkinitramfs should be checked, if they need to include
839 udevadm in the list of files.
849 The etc/udev/rules.d/ directory now contains a default set of basic
850 udev rules. This initial version is the result of a rules file merge
851 of Fedora and openSUSE. For these both distros only a few specific
852 rules are left in their own file, named after the distro. Rules which
853 are optionally installed, because they are only valid for a specific
854 architecture, or rules for subsystems which are not always used are
855 in etc/udev/packages/.
861 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
862 actions by dynamically created rules.
864 SYMLINK=="<value>" matches agains the entries in the list of
865 currently defined symlinks. The links are not created in the
866 filesystem at that point in time, but the values can be matched.
868 RUN{ignore_error}+="<program>" will ignore any exit code from the
869 program and not record as a failed event.
875 Final merge of patches/features from the Ubuntu package.
881 Control characters in filesystem label strings are no longer silenty
882 removed, but hex-encoded, to be able to uniquely identify the device
883 by its symlink in /dev/disk/by-label/.
884 If libvolume_id is used by mount(8), LABEL= will work as expected,
885 if slashes or other characters are used in the label string.
887 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
888 can be specified now. The TEST key accepts an optional mode mask
889 TEST{0100}=="<is executable file>".
891 Scsi_id now supports a mode without expecting scsi-specific sysfs
892 entries to allow the extraction of cciss-device persistent properties.
898 In the future, we may see uuid's which are just simple character
899 strings (see the DDF Raid Specification). For that reason vol_id now
900 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
901 the creation of symlinks, the *_SAFE values ensure, that no control
902 or whitespace characters are used in the filename.
904 Possible users of libvolume_id, please use the volume_id_get_* functions.
905 The public struct will go away in a future release of the library.
911 Removal of useless extras/eventrecorder.sh.
921 The directory multiplexer for dev.d/ and hotplug.d are finally removed
922 from the udev package.
928 Symlinks can have priorities now, the priority is assigned to the device
929 and specified with OPTIONS="link_priority=100". Devices with higher
930 priorities overwrite the symlinks of devices with lower priorities.
931 If the device that currently owns the link, goes away, the symlink
932 will be removed, and recreated, pointing to the next device with the
933 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
934 more reliable, if multiple devices contain the same metadata and overwrite
937 The dasd_id program is removed from the udev tree, and dasdinfo, with the
938 needed rules, are part of the s390-tools now.
940 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
941 we may get the scsi sysfs mess fixed some day, and this will only catch
942 the devices we are looking for.
944 USB serial numbers for storage devices have the target:lun now appended,
945 to make it possibble to distinguish broken multi-lun devices with all
946 the same SCSI identifiers.
948 Note: The extra "run_directory" which searches and executes stuff in
949 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
950 with the next release. Make sure, that you don't use it anymore, or
951 provides your own implementation of that inefficient stuff.
952 We are tired of reports about a "slow udev", because these directories
953 contain stuff, that runs with _every_ event, instead of using rules,
954 that run programs only for the matching events.
964 DRIVER== will match only for devices that actually have a real
965 driver. DRIVERS== must be used, if parent devices should be
966 included in the match.
968 Libvolume_id's "linux_raid" detection needed another fix.
976 Add additional check to volume_id detection of via_raid, cause
977 some company decided to put a matching pattern all over the empty
978 storage area of their music players.
982 Fix path_id for SAS devices.
986 The udev daemon can be started with --debug-trace now, which will
987 execute all events serialized to get a chance to catch a possible
988 action that crashes the box.
990 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
991 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
992 are excluded from the warning. Referencing parent attributes directly
993 may break when something in the kernel driver model changes. Udev will
994 just find the attribute by walking up the parent chain.
996 Udevtrigger now sorts the list of devices depending on the device
997 dependency, so a "usb" device is triggered after the parent "pci"
1002 Revert persistent-storage ata-serial '_' '-' replacement.
1008 Udevtrigger can now filter the list of devices to be triggered. Matches
1009 for subsystems or sysfs attributes can be specified.
1011 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1012 zero-sized files to avoid pointing to /sys and confuse broken tools which
1013 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1016 The rules and scripts to create udev rules for persistent network
1017 devices and optical drives are in the extras/rules_generator directory
1018 now. If you use something similar, please consider replacing your own
1019 version with this, to share the support effort. The rule_generator
1020 installs its own rules into /etc/udev/rules.d.
1022 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1023 the rule_generator depends on cdrom_id to be called in an earlier rule.
1029 Renaming of some key names (the old names still work):
1030 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1031 (The behavior of the key DRIVER will change soon in one of the next
1032 releases, to match only the event device, please switch to DRIVERS
1033 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1035 With the new key names, we have a more consistent and simpler scheme.
1036 We can match the properties of the event device only, with: KERNEL,
1037 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1038 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1039 longer mentioned in the man page and should be switched in the rule
1042 ATTR{file}="value" can be used now, to write to a sysfs file of the
1043 event device. Instead of:
1044 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1046 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1048 All the PHYSDEV* keys are deprecated and will be removed from a
1050 PHYDEVPATH - is the path of a parent device and should not be
1052 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1053 matched with SUBSYSTEMS==
1054 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1055 Newer kernels will have DRIVER in the environment,
1056 for older kernels udev puts in. Class device will
1057 no longer carry this property of a parent and
1058 DRIVERS== can be used to match such a parent value.
1059 Note that ENV{DRIVER} is only available for a few bus devices, where
1060 the driver is already bound at device event time. On coldplug, the
1061 events for a lot devices are already bound to a driver, and they will have
1062 that value set. But on hotplug, at the time the kernel creates the device,
1063 it can't know what driver may claim the device after that, therefore
1064 in most cases it will be empty.
1066 Failed events should now be re-triggered with:
1067 udevtrigger --retry-failed.
1068 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1069 files private to the udev tools. We may need to switch the current symlink
1070 target, cause some obviously broken tools try to scan all files in /dev
1071 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1072 million times. This takes ages on slow boxes.
1074 The udevinfo attribute walk (-a) now works with giving a device node
1075 name (-n) instead of a devpath (-p). The query now always works, also when
1076 no database file was created by udev.
1078 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1079 getpwnam() and getgrnam() now. One of the next releases will depend on
1080 fnmatch() and may use getopt_long().
1084 Bugfixes and small improvements.
1088 Fix path_id for recent kernels.
1094 Added support for swapping network interface names, by temporarily
1095 renaming the device and wait for the target name to become free.
1099 The built-in MODALIAS key and substitution is removed.
1103 The binary firmware helper is replaced by the usual simple
1104 shell script. Udevsend is removed from the tree.
1112 Some more keys require the correct use of '==' and '=' depending
1113 on the kind of operation beeing an assignment or a match. Rules
1114 with invalid operations are skipped and logged to syslog. Please
1115 test with udevtest if the parsing of your rules throws errors and
1116 fix possibly broken rules.
1120 Provide "udevsettle" to wait for all current udev events to finish.
1121 It also watches the current kernel netlink queue by comparing the
1122 even sequence number to make sure that there are no current pending
1123 events that have not already arrived in the daemon.
1127 Fix rule to skip persistent rules for removable IDE devices, which
1128 also skipped optical IDE drives.
1130 All *_id program are installed in /lib/udev/ by default now.
1132 No binary is stripped anymore as this should be done in the
1133 packaging process and not at build time.
1135 libvolume_id is provided as a shared library now and vol_id is
1136 linked against it. Also one of the next HAL versions will require
1137 this library, and the HAL build process will also require the
1138 header file to be installed. The copy of the same code in HAL will
1139 be removed to have only a single copy left on the system.
1143 Add persistent links for SCSI tapes. The rules file is renamed
1144 to 60-persistent-storage.rules.
1146 Create persistent path for usb devices. Can be used for all sorts
1147 of devices that can't be distinguished by other properties like
1148 multiple identical keyboards and mice connected to the same box.
1150 Provide "udevtrigger" program to request events on coldplug. The
1151 shell script is much too slow with thousends of devices.
1155 Fix persistent disk rules to exclude removable IDE drives.
1157 Warn if %e, $modalias or MODALIAS is used.
1161 Fix queue export, which wasn't correct for subsequent add/remove
1162 events for the same device.
1166 Fix cramfs detection on big endian.
1168 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1173 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1174 attributes were only checked at the parent device that matched the
1175 by BUS requested subsystem. Fix it to also look at the device we
1176 received the event for.
1178 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1183 Fix a bug where NAME="" would prevent RUN from beeing executed.
1185 RUN="/bin/program" does not longer automatically add the subsystem
1186 as the first parameter. This is from the days of /sbin/hotplug
1187 which is dead now and it's just confusing to need to add a space at
1188 the end of the program name to prevent this.
1189 If you use rules that need the subsystem as the first parameter,
1190 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1191 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1195 The udev man page has moved to udev(7) as it does not describe a command
1196 anymore. The programs udev, udevstart and udevsend are no longer installed
1197 by default and must be copied manually, if they should be installed or
1198 included in a package.
1200 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1201 the ignore rule was applied.
1203 More preparation for future sysfs changes. usb_id and scsi_id no longer
1204 depend on a magic order of devices in the /devices chain. Specific devices
1205 should be requested by their subsytem.
1207 This will always find the scsi parent device without depending on a specific
1209 dev = sysfs_device_get(devpath);
1210 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1212 The "device" link in the current sysfs layout will be automatically
1213 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1214 parent in the devpath. If a device is requested by it's symlink, like all
1215 class devices in the new sysfs layout will look like, it gets automatically
1216 resolved and substituted with the real devpath and not the symlink path.
1219 A similar logic must be applied to _all_ sysfs users, including
1220 scripts, that search along parent devices in sysfs. The explicit use of
1221 the "device" link must be avoided. With the future sysfs layout all
1222 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1223 back to the "class" or the "bus". The layout of the parent devices in
1224 /devices is not necessarily expected to be stable across kernel releases and
1225 searching for parents by their subsystem should make sysfs users tolerant
1226 for changed parent chains.
1230 Prepare udev to work with the experimental kernel patch, that moves
1231 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1233 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1234 moving the class devices to /sys/devices.
1236 Thanks again to Marco for help finding a hopefully nice compromise
1237 to make %b simpler and working again.
1241 Complete removal of libsysfs, replaced by simple helper functions
1242 which are much simpler and a bit faster. The udev daemon operatesentirely
1243 on event parameters and does not use sysfs for simple rules anymore.
1244 Please report any new bugs/problems, that may be caused by this big
1245 change. They will be fixed immediately.
1247 The enumeration format character '%e' is deprecated and will be
1248 removed sometimes from a future udev version. It never worked correctly
1249 outside of udevstart, so we can't use it with the new parallel
1250 coldplug. A simple enumeration is as useless as the devfs naming
1251 scheme, just get rid of both if you still use it.
1253 MODALIAS and $modalias is not needed and will be removed from one of
1254 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1255 the sysfs "modalias" value.
1257 Thanks a lot to Marco for all his help on finding and fixing bugs.
1261 Let scsi_id request libata drive serial numbers from page 0x80.
1263 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1264 added /dev/disk/by-name/* for device mapper device names.
1266 Removed %e from the man page. It never worked reliably outside
1267 of udevstart and udevstart is no longer recommended to use.
1271 Symlinks are now exported to the event environment. Hopefully it's no
1272 longer needed to run udevinfo from an event process, like it was
1273 mentioned on the hotplug list:
1274 UDEV [1134776873.702967] add@/block/sdb
1277 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1281 Fix a problem if udevsend is used as the hotplug handler and tries to use
1282 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1283 and this kind of problems will hopefully go away soon.
1287 All built-in logic to work around bad sysfs timing is removed with this
1288 version. The need to wait for sysfs files is almost fixed with a kernel
1289 version that doesn't work with this udev version anyway. Until we fix
1290 the timing of the "bus" link creation, the former integrated logic should
1291 be emulated by a rule placed before all other rules:
1292 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1294 The option "udev_db" does no longer exist. All udev state will be in
1295 /$udev_root/.udev/ now, there is no longer an option to set this
1297 If the init script or something else used this value, just depend on
1298 this hardcoded path. But remember _all_content_ of this directory is
1299 still private to udev and can change at any time.
1301 Default location for rule sripts and helper programs is now: /lib/udev/.
1302 Everything that is not useful on the commandline should go into this
1303 directory. Some of the helpers in the extras folder are installed there
1304 now. The rules need to be changed, to find the helpers there.
1306 Also /lib/udev/devices is recommended as a directory where packages or
1307 the user can place real device nodes, which get copied over to /dev at
1308 every boot. This should replace the various solutions with custom config
1311 Udevsend does no longer start the udev daemon. This must be done with
1312 the init script that prepares /dev on tmpfs and creates the initial nodes,
1313 before starting the daemon.
1317 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1320 The copy of klibc is removed. A systemwide installed version of klibc
1321 should be used to build a klibc udev now.
1325 NAME="" will not create any nodes, but execute RUN keys. To completely
1326 ignore an event the OPTION "ignore_device" should be used.
1328 After removal of the reorder queue, events with a TIMEOUT can be executed
1329 without any queuing now.
1333 Fixed bug in udevd, if inotify is not available. We depend on netlink
1334 uevents now, kernels without that event source will not work with that
1335 version of udev anymore.
1339 The rule parsing happens now in the daemon once at startup, all udev
1340 event processes inherit the already parsed rules from the daemon.
1341 It is shipped with SUSE10.0 and reduces heavily the system load at
1342 startup. The option to save precompiled rules and let the udev process
1343 pick the them up is removed, as it's no longer needed.
1345 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1346 device. Libsysfs is changed to "translate" the requested link into the
1347 real device path, as it would happen with the hotplug event. Otherwise
1348 device removal and the udev database will not work.
1350 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1353 A few improvements for vol_id, the filesytem probing code.
1357 Fix a stupid typo in extras/run_directory for "make install".
1359 scsi_id creates the temporary devnode now in /dev for usage with a
1360 non-writable /tmp directory.
1362 The uevent kernel socket buffer can carry app. 50.000 events now,
1363 let's see who can break this again. :)
1365 The upcoming kernel will have a new input driver core integration.
1366 Some class devices are now symlinks to the real device. libsysfs
1367 needs a fix for this to work correctly. Udevstart of older udev
1368 versions will _not_ create these devices!
1372 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1377 A bunch of mostly trivial bugfixes. From now on no node name or
1378 symlink name can contain any character than plain whitelisted ascii
1379 characters or validated utf8 byte-streams. This is needed for the
1380 /dev/disk/by-label/* links, because we import untrusted data and
1381 export it to the filesystem.
1385 More bugfixes. If udevd was started from the kernel, we don't
1386 have stdin/stdout/stderr, which broke the forked tools in some
1391 Bugfix. udevstart event ordering was broken for a long time.
1392 The new run_program() uncovered it, because /dev/null was not
1393 available while we try to run external programs.
1394 Now udevstart should create it before we run anything.
1398 Minor bugfixes and some distro rules updates. If you don't have the
1399 persistent disk rules in /dev/disk/by-*/* on your distro, just
1400 grab it from here. :)
1404 We can use socket communication now to pass events from udev to
1406 RUN+="socket:/org/freedesktop/hal/udev_event"
1407 will pass the whole udev event to the HAL daemon without the need
1408 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1412 Mostly bugfixes and see ChangeLog.
1414 The test for the existence of an environment value should be
1416 ENV{KEY}=="*" to ENV{KEY}=="?*"
1417 because "*" will not fail anymore, if the key does not exist or
1422 Bugfixes and a few tweaks described in the ChangeLog.
1426 Mostly a Bugfix release.
1428 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1429 timing with custom rules.
1433 We changed the internal rule storage format. Our large rule files took
1434 2 MB of RAM, with the change we are down to 99kB.
1436 If the device-node has been created with default name and no symlink or
1437 options are to remenber, it is not longer stored in the udevdb. HAL will
1438 need to be updated to work correctly with that change.
1440 To overrride optimization flags, OPTFLAGS may be used now.
1448 Major changes happened with this release. The goal is to take over the
1449 complete kernel-event handling and provide a more efficient way to dispatch
1450 kernel events. Replacing most of the current shell script logic and the
1451 kernel forked helper with a netlink-daemon and a rule-based event handling.
1453 o udevd listens to netlink events now. The first valid netlink event
1454 will make udevd ignore any message from udevsend that contains a
1455 SEQNUM, to avoid duplicate events. The forked events can be disabled
1457 echo "" > /proc/sys/kernel/hotplug
1458 For full support, the broken input-subsytem needs to be fixed, not to
1459 bypass the driver core.
1461 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1462 removed from udev itself and must be emulated by calling small
1463 helper binaries provided in the extras folder:
1464 make EXTRAS=extras/run_directory/
1465 will build udev_run_devd and udev_run_hotplugd, which can be called
1466 from a rule if needed:
1467 RUN+="/sbin/udev_run_hotplugd"
1468 The recommended way to handle this is to convert all the calls from
1469 the directories to explicit udev rules and get completely rid of the
1470 multiplexing. (To catch a ttyUSB event, you now no longer need to
1471 fork and exit 300 tty script instances you are not interested in, it
1472 is just one rule that matches exactly the device.)
1474 o udev handles now _all_ events not just events for class and block
1475 devices, this way it is possible to control the complete event
1476 behavior with udev rules. Especially useful for rules like:
1477 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1479 o As used in the modalias rule, udev supports now textual
1480 substitution placeholder along with the usual format chars. This
1481 needs to be documented, for now it's only visible in udev_rules_parse.c.
1483 o The rule keys support now more operations. This is documented in the
1484 man page. It is possible to add values to list-keys like the SYMLINK
1485 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1486 Also "final"-assignments are supported by using KEY:="value", which will
1487 prevent changing the key by any later rule.
1489 o kernel 2.6.12 has the "detached_state" attribute removed from
1490 sysfs, which was used to recognize sysfs population. We switched that
1491 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1492 Running this udev version on older kernels may cause a short delay for
1495 o To provide infrastructure for persistent device naming, the id programs:
1496 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1497 to export the probed data in environment key format:
1498 pim:~ # /sbin/ata_id --export /dev/hda
1499 ID_MODEL=HTS726060M9AT00
1500 ID_SERIAL=MRH401M4G6UM9B
1501 ID_REVISION=MH4OA6BA
1503 The following rules:
1504 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1505 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1508 kay@pim:~> tree /dev/disk
1511 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1512 | `-- IBM-Memory_Key -> ../../sda
1514 | |-- swap -> ../../hda1
1515 | |-- date -> ../../sda1
1516 | `-- home -> ../../hda3
1518 |-- 2E08712B0870F2E7 -> ../../hda3
1519 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1520 |-- E845-7A89 -> ../../sda1
1521 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1523 The IMPORT= operation will import these keys in the environment and make
1524 it available for later PROGRAM= and RUN= executed programs. The keys are
1525 also stored in the udevdb and can be queried from there with one of the
1528 o A few binaries are silently added to the repository, which can be used
1529 to replay kernel events from initramfs instead of using coldplug. udevd
1530 can be instructed now to queue-up events while the stored events from
1531 initramfs are filled into the udevd-queue. This code is still under
1532 development and there is no documentation now besides the code itself.
1533 The additional binaries get compiled, but are not installed by default.
1535 o There is also a temporary fix for a performance problem where too many
1536 events happen in parallel and every event needs to parse the rules.
1537 udev can now read precompiled rules stored on disk. This is likely to be
1538 replaced by a more elegant solution in a future udev version.
1542 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1543 Fix for libsysfs not to expect this file was added.
1547 All rules are applied now, but only the first matching rule with a NAME-key
1548 will be applied. All later rules with NAME-key are completely ignored. This
1549 way system supplied symlinks or permissions gets applied to user-defined
1553 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1554 to some rules, to keep the old behavior.
1556 The rules are read on "remove"-events too. That makes is possible to match
1557 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1558 instruct udev to ignore an event (OPTIONS="ignore_device").
1559 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1561 The new RUN-key supports rule-based execution of programs after device-node
1562 handling. This is meant as a general replacement for the dev.d/-directories
1563 to give fine grained control over the execution of programs.
1565 The %s{}-sysfs format char replacement values are searched at any of the
1566 devices in the device chain now, not only at the class-device.
1568 We support log priority levels now. The value udev_log in udev.conf is used
1569 to determine what is printed to syslog. This makes it possible to
1570 run a version with compiled-in debug messages in a production environment
1571 which is sometimes needed to find a bug.
1572 It is still possible to supress the inclusion of _any_ syslog usage with
1573 USE_LOG=false to create the smallest possible binaries if needed.
1574 The configured udev_log value can be overridden with the environment variable
1579 Possible use of a system-wide klibc:
1580 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1581 will link against an external klibc and our own version will be ignored.
1585 We support an unlimited count of symlinks now.
1587 If USE_STATIC=true is passed to a glibc build, we link statically and use
1588 a built-in userdb parser to resolve user and group names.
1590 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1591 we walk up the chain of physical devices to find a match.
1593 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1594 easy to skip certain attribute matches without composing rules with weird
1595 character class negations like:
1596 KERNEL="[!s][!c][!d]*"
1597 this can now be replaced with:
1599 The current simple '=' is still supported, and should work as it does today,
1600 but existing rules should be converted if possible, to be better readable.
1602 We have new ENV{}== key now, to match against a maximum of 5 environment
1605 udevstart is its own binary again, because we don't need co carry this araound
1606 with every forked event.