5 The symlinks udevcontrol and udevtrigger are no longer installed by
8 The scsi_id program does not depend on sysfs anymore. It can speak
9 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
10 data, which should solve some old problems with tape devices, where
11 we better do not open all tape device nodes to identify the device.
17 The cdrom_id program is replaced by an advanced version, which can
18 detect most common device types, and also properties of the inserted
19 media. This is part of moving some basic functionality from HAL into
20 udev (and the kernel).
26 The last WAIT_FOR_SYSFS rule is removed from the default rules.
28 The symlinks to udevadm for the debugging tools: udevmonitor and
29 udevtest are no longer created.
31 The symlinks to the udevadm man page for the old tool names are
34 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
35 should be prefixed with '@' to indicate that the path is not a
46 Udevstart is removed from the tree, it did not get installed for
47 a long time now, and is long replaced by trigger and settle.
53 All udev tools are merged into a single binary called udevadm.
54 The old names of the tools are built-in commands in udevadm now.
55 Symlinks to udevadm, with the names of the old tools, provide
56 the same functionality as the standalone tools. There is also
57 only a single udevadm.8 man page left for all tools.
59 Tools like mkinitramfs should be checked, if they need to include
60 udevadm in the list of files.
70 The etc/udev/rules.d/ directory now contains a default set of basic
71 udev rules. This initial version is the result of a rules file merge
72 of Fedora and openSUSE. For these both distros only a few specific
73 rules are left in their own file, named after the distro. Rules which
74 are optionally installed, because they are only valid for a specific
75 architecture, or rules for subsystems which are not always used are
76 in etc/udev/packages/.
82 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
83 actions by dynamically created rules.
85 SYMLINK=="<value>" matches agains the entries in the list of
86 currently defined symlinks. The links are not created in the
87 filesystem at that point in time, but the values can be matched.
89 RUN{ignore_error}+="<program>" will ignore any exit code from the
90 program and not record as a failed event.
96 Final merge of patches/features from the Ubuntu package.
102 Control characters in filesystem label strings are no longer silenty
103 removed, but hex-encoded, to be able to uniquely identify the device
104 by its symlink in /dev/disk/by-label/.
105 If libvolume_id is used by mount(8), LABEL= will work as expected,
106 if slashes or other characters are used in the label string.
108 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
109 can be specified now. The TEST key accepts an optional mode mask
110 TEST{0100}=="<is executable file>".
112 Scsi_id now supports a mode without expecting scsi-specific sysfs
113 entries to allow the extraction of cciss-device persistent properties.
119 In the future, we may see uuid's which are just simple character
120 strings (see the DDF Raid Specification). For that reason vol_id now
121 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
122 the creation of symlinks, the *_SAFE values ensure, that no control
123 or whitespace characters are used in the filename.
125 Possible users of libvolume_id, please use the volume_id_get_* functions.
126 The public struct will go away in a future release of the library.
132 Removal of useless extras/eventrecorder.sh.
142 The directory multiplexer for dev.d/ and hotplug.d are finally removed
143 from the udev package.
149 Symlinks can have priorities now, the priority is assigned to the device
150 and specified with OPTIONS="link_priority=100". Devices with higher
151 priorities overwrite the symlinks of devices with lower priorities.
152 If the device that currently owns the link, goes away, the symlink
153 will be removed, and recreated, pointing to the next device with the
154 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
155 more reliable, if multiple devices contain the same metadata and overwrite
158 The dasd_id program is removed from the udev tree, and dasdinfo, with the
159 needed rules, are part of the s390-tools now.
161 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
162 we may get the scsi sysfs mess fixed some day, and this will only catch
163 the devices we are looking for.
165 USB serial numbers for storage devices have the target:lun now appended,
166 to make it possibble to distinguish broken multi-lun devices with all
167 the same SCSI identifiers.
169 Note: The extra "run_directory" which searches and executes stuff in
170 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
171 with the next release. Make sure, that you don't use it anymore, or
172 provides your own implementation of that inefficient stuff.
173 We are tired of reports about a "slow udev", because these directories
174 contain stuff, that runs with _every_ event, instead of using rules,
175 that run programs only for the matching events.
185 DRIVER== will match only for devices that actually have a real
186 driver. DRIVERS== must be used, if parent devices should be
187 included in the match.
189 Libvolume_id's "linux_raid" detection needed another fix.
197 Add additional check to volume_id detection of via_raid, cause
198 some company decided to put a matching pattern all over the empty
199 storage area of their music players.
203 Fix path_id for SAS devices.
207 The udev daemon can be started with --debug-trace now, which will
208 execute all events serialized to get a chance to catch a possible
209 action that crashes the box.
211 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
212 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
213 are excluded from the warning. Referencing parent attributes directly
214 may break when something in the kernel driver model changes. Udev will
215 just find the attribute by walking up the parent chain.
217 Udevtrigger now sorts the list of devices depending on the device
218 dependency, so a "usb" device is triggered after the parent "pci"
223 Revert persistent-storage ata-serial '_' '-' replacement.
229 Udevtrigger can now filter the list of devices to be triggered. Matches
230 for subsystems or sysfs attributes can be specified.
232 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
233 zero-sized files to avoid pointing to /sys and confuse broken tools which
234 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
237 The rules and scripts to create udev rules for persistent network
238 devices and optical drives are in the extras/rules_generator directory
239 now. If you use something similar, please consider replacing your own
240 version with this, to share the support effort. The rule_generator
241 installs its own rules into /etc/udev/rules.d.
243 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
244 the rule_generator depends on cdrom_id to be called in an earlier rule.
250 Renaming of some key names (the old names still work):
251 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
252 (The behavior of the key DRIVER will change soon in one of the next
253 releases, to match only the event device, please switch to DRIVERS
254 instead. If DRIVER is used, it will behave like DRIVERS, but an error
256 With the new key names, we have a more consistent and simpler scheme.
257 We can match the properties of the event device only, with: KERNEL,
258 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
259 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
260 longer mentioned in the man page and should be switched in the rule
263 ATTR{file}="value" can be used now, to write to a sysfs file of the
264 event device. Instead of:
265 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
267 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
269 All the PHYSDEV* keys are deprecated and will be removed from a
271 PHYDEVPATH - is the path of a parent device and should not be
273 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
274 matched with SUBSYSTEMS==
275 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
276 Newer kernels will have DRIVER in the environment,
277 for older kernels udev puts in. Class device will
278 no longer carry this property of a parent and
279 DRIVERS== can be used to match such a parent value.
280 Note that ENV{DRIVER} is only available for a few bus devices, where
281 the driver is already bound at device event time. On coldplug, the
282 events for a lot devices are already bound to a driver, and they will have
283 that value set. But on hotplug, at the time the kernel creates the device,
284 it can't know what driver may claim the device after that, therefore
285 in most cases it will be empty.
287 Failed events should now be re-triggered with:
288 udevtrigger --retry-failed.
289 Please switch to this command, so we keep the details of the /dev/.udev/failed/
290 files private to the udev tools. We may need to switch the current symlink
291 target, cause some obviously broken tools try to scan all files in /dev
292 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
293 million times. This takes ages on slow boxes.
295 The udevinfo attribute walk (-a) now works with giving a device node
296 name (-n) instead of a devpath (-p). The query now always works, also when
297 no database file was created by udev.
299 The built-in /etc/passwd /etc/group parser is removed, we always depend on
300 getpwnam() and getgrnam() now. One of the next releases will depend on
301 fnmatch() and may use getopt_long().
305 Bugfixes and small improvements.
309 Fix path_id for recent kernels.
315 Added support for swapping network interface names, by temporarily
316 renaming the device and wait for the target name to become free.
320 The built-in MODALIAS key and substitution is removed.
324 The binary firmware helper is replaced by the usual simple
325 shell script. Udevsend is removed from the tree.
333 Some more keys require the correct use of '==' and '=' depending
334 on the kind of operation beeing an assignment or a match. Rules
335 with invalid operations are skipped and logged to syslog. Please
336 test with udevtest if the parsing of your rules throws errors and
337 fix possibly broken rules.
341 Provide "udevsettle" to wait for all current udev events to finish.
342 It also watches the current kernel netlink queue by comparing the
343 even sequence number to make sure that there are no current pending
344 events that have not already arrived in the daemon.
348 Fix rule to skip persistent rules for removable IDE devices, which
349 also skipped optical IDE drives.
351 All *_id program are installed in /lib/udev/ by default now.
353 No binary is stripped anymore as this should be done in the
354 packaging process and not at build time.
356 libvolume_id is provided as a shared library now and vol_id is
357 linked against it. Also one of the next HAL versions will require
358 this library, and the HAL build process will also require the
359 header file to be installed. The copy of the same code in HAL will
360 be removed to have only a single copy left on the system.
364 Add persistent links for SCSI tapes. The rules file is renamed
365 to 60-persistent-storage.rules.
367 Create persistent path for usb devices. Can be used for all sorts
368 of devices that can't be distinguished by other properties like
369 multiple identical keyboards and mice connected to the same box.
371 Provide "udevtrigger" program to request events on coldplug. The
372 shell script is much too slow with thousends of devices.
376 Fix persistent disk rules to exclude removable IDE drives.
378 Warn if %e, $modalias or MODALIAS is used.
382 Fix queue export, which wasn't correct for subsequent add/remove
383 events for the same device.
387 Fix cramfs detection on big endian.
389 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
394 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
395 attributes were only checked at the parent device that matched the
396 by BUS requested subsystem. Fix it to also look at the device we
397 received the event for.
399 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
404 Fix a bug where NAME="" would prevent RUN from beeing executed.
406 RUN="/bin/program" does not longer automatically add the subsystem
407 as the first parameter. This is from the days of /sbin/hotplug
408 which is dead now and it's just confusing to need to add a space at
409 the end of the program name to prevent this.
410 If you use rules that need the subsystem as the first parameter,
411 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
412 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
416 The udev man page has moved to udev(7) as it does not describe a command
417 anymore. The programs udev, udevstart and udevsend are no longer installed
418 by default and must be copied manually, if they should be installed or
419 included in a package.
421 Fix a bug where "ignore_device" could run earlier collected RUN keys before
422 the ignore rule was applied.
424 More preparation for future sysfs changes. usb_id and scsi_id no longer
425 depend on a magic order of devices in the /devices chain. Specific devices
426 should be requested by their subsytem.
428 This will always find the scsi parent device without depending on a specific
430 dev = sysfs_device_get(devpath);
431 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
433 The "device" link in the current sysfs layout will be automatically
434 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
435 parent in the devpath. If a device is requested by it's symlink, like all
436 class devices in the new sysfs layout will look like, it gets automatically
437 resolved and substituted with the real devpath and not the symlink path.
440 A similar logic must be applied to _all_ sysfs users, including
441 scripts, that search along parent devices in sysfs. The explicit use of
442 the "device" link must be avoided. With the future sysfs layout all
443 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
444 back to the "class" or the "bus". The layout of the parent devices in
445 /devices is not necessarily expected to be stable across kernel releases and
446 searching for parents by their subsystem should make sysfs users tolerant
447 for changed parent chains.
451 Prepare udev to work with the experimental kernel patch, that moves
452 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
454 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
455 moving the class devices to /sys/devices.
457 Thanks again to Marco for help finding a hopefully nice compromise
458 to make %b simpler and working again.
462 Complete removal of libsysfs, replaced by simple helper functions
463 which are much simpler and a bit faster. The udev daemon operatesentirely
464 on event parameters and does not use sysfs for simple rules anymore.
465 Please report any new bugs/problems, that may be caused by this big
466 change. They will be fixed immediately.
468 The enumeration format character '%e' is deprecated and will be
469 removed sometimes from a future udev version. It never worked correctly
470 outside of udevstart, so we can't use it with the new parallel
471 coldplug. A simple enumeration is as useless as the devfs naming
472 scheme, just get rid of both if you still use it.
474 MODALIAS and $modalias is not needed and will be removed from one of
475 the next udev versions, replace it in all rules with ENV{MODALIAS} or
476 the sysfs "modalias" value.
478 Thanks a lot to Marco for all his help on finding and fixing bugs.
482 Let scsi_id request libata drive serial numbers from page 0x80.
484 Renamed etc/udev/persistent.rules to persistent-disk.rules and
485 added /dev/disk/by-name/* for device mapper device names.
487 Removed %e from the man page. It never worked reliably outside
488 of udevstart and udevstart is no longer recommended to use.
492 Symlinks are now exported to the event environment. Hopefully it's no
493 longer needed to run udevinfo from an event process, like it was
494 mentioned on the hotplug list:
495 UDEV [1134776873.702967] add@/block/sdb
498 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
502 Fix a problem if udevsend is used as the hotplug handler and tries to use
503 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
504 and this kind of problems will hopefully go away soon.
508 All built-in logic to work around bad sysfs timing is removed with this
509 version. The need to wait for sysfs files is almost fixed with a kernel
510 version that doesn't work with this udev version anyway. Until we fix
511 the timing of the "bus" link creation, the former integrated logic should
512 be emulated by a rule placed before all other rules:
513 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
515 The option "udev_db" does no longer exist. All udev state will be in
516 /$udev_root/.udev/ now, there is no longer an option to set this
518 If the init script or something else used this value, just depend on
519 this hardcoded path. But remember _all_content_ of this directory is
520 still private to udev and can change at any time.
522 Default location for rule sripts and helper programs is now: /lib/udev/.
523 Everything that is not useful on the commandline should go into this
524 directory. Some of the helpers in the extras folder are installed there
525 now. The rules need to be changed, to find the helpers there.
527 Also /lib/udev/devices is recommended as a directory where packages or
528 the user can place real device nodes, which get copied over to /dev at
529 every boot. This should replace the various solutions with custom config
532 Udevsend does no longer start the udev daemon. This must be done with
533 the init script that prepares /dev on tmpfs and creates the initial nodes,
534 before starting the daemon.
538 Silent a too verbose error logging for the old hotplug.d/ dev.d/
541 The copy of klibc is removed. A systemwide installed version of klibc
542 should be used to build a klibc udev now.
546 NAME="" will not create any nodes, but execute RUN keys. To completely
547 ignore an event the OPTION "ignore_device" should be used.
549 After removal of the reorder queue, events with a TIMEOUT can be executed
550 without any queuing now.
554 Fixed bug in udevd, if inotify is not available. We depend on netlink
555 uevents now, kernels without that event source will not work with that
556 version of udev anymore.
560 The rule parsing happens now in the daemon once at startup, all udev
561 event processes inherit the already parsed rules from the daemon.
562 It is shipped with SUSE10.0 and reduces heavily the system load at
563 startup. The option to save precompiled rules and let the udev process
564 pick the them up is removed, as it's no longer needed.
566 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
567 device. Libsysfs is changed to "translate" the requested link into the
568 real device path, as it would happen with the hotplug event. Otherwise
569 device removal and the udev database will not work.
571 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
574 A few improvements for vol_id, the filesytem probing code.
578 Fix a stupid typo in extras/run_directory for "make install".
580 scsi_id creates the temporary devnode now in /dev for usage with a
581 non-writable /tmp directory.
583 The uevent kernel socket buffer can carry app. 50.000 events now,
584 let's see who can break this again. :)
586 The upcoming kernel will have a new input driver core integration.
587 Some class devices are now symlinks to the real device. libsysfs
588 needs a fix for this to work correctly. Udevstart of older udev
589 versions will _not_ create these devices!
593 Fix a 'install' target in the Makefile, that prevents EXTRAS from
598 A bunch of mostly trivial bugfixes. From now on no node name or
599 symlink name can contain any character than plain whitelisted ascii
600 characters or validated utf8 byte-streams. This is needed for the
601 /dev/disk/by-label/* links, because we import untrusted data and
602 export it to the filesystem.
606 More bugfixes. If udevd was started from the kernel, we don't
607 have stdin/stdout/stderr, which broke the forked tools in some
612 Bugfix. udevstart event ordering was broken for a long time.
613 The new run_program() uncovered it, because /dev/null was not
614 available while we try to run external programs.
615 Now udevstart should create it before we run anything.
619 Minor bugfixes and some distro rules updates. If you don't have the
620 persistent disk rules in /dev/disk/by-*/* on your distro, just
621 grab it from here. :)
625 We can use socket communication now to pass events from udev to
627 RUN+="socket:/org/freedesktop/hal/udev_event"
628 will pass the whole udev event to the HAL daemon without the need
629 for a forked helper. (See ChangeLog for udevmonitor, as an example)
633 Mostly bugfixes and see ChangeLog.
635 The test for the existence of an environment value should be
637 ENV{KEY}=="*" to ENV{KEY}=="?*"
638 because "*" will not fail anymore, if the key does not exist or
643 Bugfixes and a few tweaks described in the ChangeLog.
647 Mostly a Bugfix release.
649 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
650 timing with custom rules.
654 We changed the internal rule storage format. Our large rule files took
655 2 MB of RAM, with the change we are down to 99kB.
657 If the device-node has been created with default name and no symlink or
658 options are to remenber, it is not longer stored in the udevdb. HAL will
659 need to be updated to work correctly with that change.
661 To overrride optimization flags, OPTFLAGS may be used now.
669 Major changes happened with this release. The goal is to take over the
670 complete kernel-event handling and provide a more efficient way to dispatch
671 kernel events. Replacing most of the current shell script logic and the
672 kernel forked helper with a netlink-daemon and a rule-based event handling.
674 o udevd listens to netlink events now. The first valid netlink event
675 will make udevd ignore any message from udevsend that contains a
676 SEQNUM, to avoid duplicate events. The forked events can be disabled
678 echo "" > /proc/sys/kernel/hotplug
679 For full support, the broken input-subsytem needs to be fixed, not to
680 bypass the driver core.
682 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
683 removed from udev itself and must be emulated by calling small
684 helper binaries provided in the extras folder:
685 make EXTRAS=extras/run_directory/
686 will build udev_run_devd and udev_run_hotplugd, which can be called
687 from a rule if needed:
688 RUN+="/sbin/udev_run_hotplugd"
689 The recommended way to handle this is to convert all the calls from
690 the directories to explicit udev rules and get completely rid of the
691 multiplexing. (To catch a ttyUSB event, you now no longer need to
692 fork and exit 300 tty script instances you are not interested in, it
693 is just one rule that matches exactly the device.)
695 o udev handles now _all_ events not just events for class and block
696 devices, this way it is possible to control the complete event
697 behavior with udev rules. Especially useful for rules like:
698 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
700 o As used in the modalias rule, udev supports now textual
701 substitution placeholder along with the usual format chars. This
702 needs to be documented, for now it's only visible in udev_rules_parse.c.
704 o The rule keys support now more operations. This is documented in the
705 man page. It is possible to add values to list-keys like the SYMLINK
706 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
707 Also "final"-assignments are supported by using KEY:="value", which will
708 prevent changing the key by any later rule.
710 o kernel 2.6.12 has the "detached_state" attribute removed from
711 sysfs, which was used to recognize sysfs population. We switched that
712 to wait for the "bus" link, which is only available in kernels after 2.6.11.
713 Running this udev version on older kernels may cause a short delay for
716 o To provide infrastructure for persistent device naming, the id programs:
717 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
718 to export the probed data in environment key format:
719 pim:~ # /sbin/ata_id --export /dev/hda
720 ID_MODEL=HTS726060M9AT00
721 ID_SERIAL=MRH401M4G6UM9B
725 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
726 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
729 kay@pim:~> tree /dev/disk
732 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
733 | `-- IBM-Memory_Key -> ../../sda
735 | |-- swap -> ../../hda1
736 | |-- date -> ../../sda1
737 | `-- home -> ../../hda3
739 |-- 2E08712B0870F2E7 -> ../../hda3
740 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
741 |-- E845-7A89 -> ../../sda1
742 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
744 The IMPORT= operation will import these keys in the environment and make
745 it available for later PROGRAM= and RUN= executed programs. The keys are
746 also stored in the udevdb and can be queried from there with one of the
749 o A few binaries are silently added to the repository, which can be used
750 to replay kernel events from initramfs instead of using coldplug. udevd
751 can be instructed now to queue-up events while the stored events from
752 initramfs are filled into the udevd-queue. This code is still under
753 development and there is no documentation now besides the code itself.
754 The additional binaries get compiled, but are not installed by default.
756 o There is also a temporary fix for a performance problem where too many
757 events happen in parallel and every event needs to parse the rules.
758 udev can now read precompiled rules stored on disk. This is likely to be
759 replaced by a more elegant solution in a future udev version.
763 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
764 Fix for libsysfs not to expect this file was added.
768 All rules are applied now, but only the first matching rule with a NAME-key
769 will be applied. All later rules with NAME-key are completely ignored. This
770 way system supplied symlinks or permissions gets applied to user-defined
774 Please check your rules setup, if you may need to add OPTIONS="last_rule"
775 to some rules, to keep the old behavior.
777 The rules are read on "remove"-events too. That makes is possible to match
778 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
779 instruct udev to ignore an event (OPTIONS="ignore_device").
780 The new ACTION-key may be used to let a rule act only at a "remove"-event.
782 The new RUN-key supports rule-based execution of programs after device-node
783 handling. This is meant as a general replacement for the dev.d/-directories
784 to give fine grained control over the execution of programs.
786 The %s{}-sysfs format char replacement values are searched at any of the
787 devices in the device chain now, not only at the class-device.
789 We support log priority levels now. The value udev_log in udev.conf is used
790 to determine what is printed to syslog. This makes it possible to
791 run a version with compiled-in debug messages in a production environment
792 which is sometimes needed to find a bug.
793 It is still possible to supress the inclusion of _any_ syslog usage with
794 USE_LOG=false to create the smallest possible binaries if needed.
795 The configured udev_log value can be overridden with the environment variable
800 Possible use of a system-wide klibc:
801 make USE_KLIBC=true KLCC=/usr/bin/klcc all
802 will link against an external klibc and our own version will be ignored.
806 We support an unlimited count of symlinks now.
808 If USE_STATIC=true is passed to a glibc build, we link statically and use
809 a built-in userdb parser to resolve user and group names.
811 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
812 we walk up the chain of physical devices to find a match.
814 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
815 easy to skip certain attribute matches without composing rules with weird
816 character class negations like:
817 KERNEL="[!s][!c][!d]*"
818 this can now be replaced with:
820 The current simple '=' is still supported, and should work as it does today,
821 but existing rules should be converted if possible, to be better readable.
823 We have new ENV{}== key now, to match against a maximum of 5 environment
826 udevstart is its own binary again, because we don't need co carry this araound
827 with every forked event.