3 Minor bugfixes and some distro rules updates. If you don't have the
4 persistent disk rules in /dev/disk/by-*/* on your distro, just
9 We can use socket communication now to pass events from udev to
11 RUN+="socket:/org/freedesktop/hal/udev_event"
12 will pass the whole udev event to the HAL daemon without the need
13 for a forked helper. (See ChangeLog for udevmonitor, as an example)
17 Mostly bugfixes and see ChangeLog.
19 The test for the existence of an environment value should be
21 ENV{KEY}=="*" to ENV{KEY}=="?*"
22 cause "*" will not fail anymore, if the key does not exist or
27 Bugfixes and a few tweaks described in the ChangeLog.
31 Mostly a Bugfix release.
33 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
34 timing with custom rules.
38 We changed the internal rule storage format. Our large rule files took
39 2 MB of RAM, with the change we are down to 99kB.
41 If the device-node has been created with default name and no symlink or
42 options are to remenber, it is not longer stored in the udevdb. HAL will
43 need to be updated to work correctly with that change.
45 To overrride optimization flags, OPTFLAGS may be used now.
53 Major changes happened with this release. The goal is to take over the
54 complete kernel-event handling and provide a more efficient way to dispatch
55 kernel events. Replacing most of the current shell script logic and the
56 kernel forked helper with a netlink-daemon and a rule-based event handling.
58 o udevd listens to netlink events now. The first valid netlink event
59 will make udevd ignore any message from udevsend that contains a
60 SEQNUM, to avoid duplicate events. The forked events can be disabled
62 echo "" > /proc/sys/kernel/hotplug
63 For full support, the broken input-subsytem needs to be fixed, not to
64 bypass the driver core.
66 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
67 removed from udev itself and must be emulated by calling small
68 helper binaries provided in the extras folder:
69 make EXTRAS=extras/run_directory/
70 will build udev_run_devd and udev_run_hotplugd, which can be called
71 from a rule if needed:
72 RUN+="/sbin/udev_run_hotplugd"
73 The recommended way to handle this is to convert all the calls from
74 the directories to explicit udev rules and get completely rid of the
75 multiplexing. (To catch a ttyUSB event, you now no longer need to
76 fork and exit 300 tty script instances you are not interested in, it
77 is just one rule that matches exactly the device.)
79 o udev handles now _all_ events not just events for class and block
80 devices, this way it is possible to control the complete event
81 behavior with udev rules. Especially useful for rules like:
82 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
84 o As used in the modalias rule, udev supports now textual
85 substitution placeholder along with the usual format chars. This
86 needs to be documented, for now it's only visible in udev_rules_parse.c.
88 o The rule keys support now more operations. This is documented in the
89 man page. It is possible to add values to list-keys like the SYMLINK
90 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
91 Also "final"-assignments are supported by using KEY:="value", which will
92 prevent changing the key by any later rule.
94 o kernel 2.6.12 has the "detached_state" attribute removed from
95 sysfs, which was used to recognize sysfs population. We switched that
96 to wait for the "bus" link, which is only available in kernels after 2.6.11.
97 Running this udev version on older kernels may cause a short delay for
100 o To provide infrastructure for persistent device naming, the id programs:
101 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
102 to export the probed data in environment key format:
103 pim:~ # /sbin/ata_id --export /dev/hda
104 ID_MODEL=HTS726060M9AT00
105 ID_SERIAL=MRH401M4G6UM9B
109 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
110 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
113 kay@pim:~> tree /dev/disk
116 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
117 | `-- IBM-Memory_Key -> ../../sda
119 | |-- swap -> ../../hda1
120 | |-- date -> ../../sda1
121 | `-- home -> ../../hda3
123 |-- 2E08712B0870F2E7 -> ../../hda3
124 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
125 |-- E845-7A89 -> ../../sda1
126 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
128 The IMPORT= operation will import these keys in the environment and make
129 it available for later PROGRAM= and RUN= executed programs. The keys are
130 also stored in the udevdb and can be queried from there with one of the
133 o A few binaries are silently added to the repository, which can be used
134 to replay kernel events from initramfs instead of using coldplug. udevd
135 can be instructed now to queue-up events while the stored events from
136 initramfs are filled into the udevd-queue. This code is still under
137 development and there is no documentation now besides the code itself.
138 The additional binaries get compiled, but are not installed by default.
140 o There is also a temporary fix for a performance problem where too many
141 events happen in parallel and every event needs to parse the rules.
142 udev can now read precompiled rules stored on disk. This is likely to be
143 replaced by a more elegant solution in a future udev version.
147 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
148 Fix for libsysfs not to expect this file was added.
152 All rules are applied now, but only the first matching rule with a NAME-key
153 will be applied. All later rules with NAME-key are completely ignored. This
154 way system supplied symlinks or permissions gets applied to user-defined
158 Please check your rules setup, if you may need to add OPTIONS="last_rule"
159 to some rules, to keep the old behavior.
161 The rules are read on "remove"-events too. That makes is possible to match
162 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
163 instruct udev to ignore an event (OPTIONS="ignore_device").
164 The new ACTION-key may be used to let a rule act only at a "remove"-event.
166 The new RUN-key supports rule-based execution of programs after device-node
167 handling. This is meant as a general replacement for the dev.d/-directories
168 to give fine grained control over the execution of programs.
170 The %s{}-sysfs format char replacement values are searched at any of the
171 devices in the device chain now, not only at the class-device.
173 We support log priority levels now. The value udev_log in udev.conf is used
174 to determine what is printed to syslog. This makes it possible to
175 run a version with compiled-in debug messages in a production environment
176 which is sometimes needed to find a bug.
177 It is still possible to supress the inclusion of _any_ syslog usage with
178 USE_LOG=false to create the smallest possible binaries if needed.
179 The configured udev_log value can be overridden with the environment variable
184 Possible use of a system-wide klibc:
185 make USE_KLIBC=true KLCC=/usr/bin/klcc all
186 will link against an external klibc and our own version will be ignored.
190 We support an unlimited count of symlinks now.
192 If USE_STATIC=true is passed to a glibc build, we link statically and use
193 a built-in userdb parser to resolve user and group names.
195 The PLACE= key is gone. It can be replaced by an ID= for a long time, cause
196 we walk up the chain of physical devices to find a match.
198 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
199 easy to skip certain attribute matches without composing rules with weird
200 character class negations like:
201 KERNEL="[!s][!c][!d]*"
202 this can now be replaced with:
204 The current simple '=' is still supported, and should work as it does today,
205 but existing rules should be converted if possible, to be better readable.
207 We have new ENV{}== key now, to match against a maximum of 5 environment
210 udevstart is its own binary again, cause we don't need co carry this araound
211 with every forked event.