3 More bugfixes. If udevd was started from the kernel, we don't
4 have stdin/stdout/stderr, which broke the forked tools in some
9 Bugfix. udevstart event ordering was broken for a long time.
10 The new run_program() uncovered it, cause /dev/null was not
11 available while we try to run external programs.
12 Now udevstart should create it before we run anything.
16 Minor bugfixes and some distro rules updates. If you don't have the
17 persistent disk rules in /dev/disk/by-*/* on your distro, just
22 We can use socket communication now to pass events from udev to
24 RUN+="socket:/org/freedesktop/hal/udev_event"
25 will pass the whole udev event to the HAL daemon without the need
26 for a forked helper. (See ChangeLog for udevmonitor, as an example)
30 Mostly bugfixes and see ChangeLog.
32 The test for the existence of an environment value should be
34 ENV{KEY}=="*" to ENV{KEY}=="?*"
35 cause "*" will not fail anymore, if the key does not exist or
40 Bugfixes and a few tweaks described in the ChangeLog.
44 Mostly a Bugfix release.
46 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
47 timing with custom rules.
51 We changed the internal rule storage format. Our large rule files took
52 2 MB of RAM, with the change we are down to 99kB.
54 If the device-node has been created with default name and no symlink or
55 options are to remenber, it is not longer stored in the udevdb. HAL will
56 need to be updated to work correctly with that change.
58 To overrride optimization flags, OPTFLAGS may be used now.
66 Major changes happened with this release. The goal is to take over the
67 complete kernel-event handling and provide a more efficient way to dispatch
68 kernel events. Replacing most of the current shell script logic and the
69 kernel forked helper with a netlink-daemon and a rule-based event handling.
71 o udevd listens to netlink events now. The first valid netlink event
72 will make udevd ignore any message from udevsend that contains a
73 SEQNUM, to avoid duplicate events. The forked events can be disabled
75 echo "" > /proc/sys/kernel/hotplug
76 For full support, the broken input-subsytem needs to be fixed, not to
77 bypass the driver core.
79 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
80 removed from udev itself and must be emulated by calling small
81 helper binaries provided in the extras folder:
82 make EXTRAS=extras/run_directory/
83 will build udev_run_devd and udev_run_hotplugd, which can be called
84 from a rule if needed:
85 RUN+="/sbin/udev_run_hotplugd"
86 The recommended way to handle this is to convert all the calls from
87 the directories to explicit udev rules and get completely rid of the
88 multiplexing. (To catch a ttyUSB event, you now no longer need to
89 fork and exit 300 tty script instances you are not interested in, it
90 is just one rule that matches exactly the device.)
92 o udev handles now _all_ events not just events for class and block
93 devices, this way it is possible to control the complete event
94 behavior with udev rules. Especially useful for rules like:
95 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
97 o As used in the modalias rule, udev supports now textual
98 substitution placeholder along with the usual format chars. This
99 needs to be documented, for now it's only visible in udev_rules_parse.c.
101 o The rule keys support now more operations. This is documented in the
102 man page. It is possible to add values to list-keys like the SYMLINK
103 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
104 Also "final"-assignments are supported by using KEY:="value", which will
105 prevent changing the key by any later rule.
107 o kernel 2.6.12 has the "detached_state" attribute removed from
108 sysfs, which was used to recognize sysfs population. We switched that
109 to wait for the "bus" link, which is only available in kernels after 2.6.11.
110 Running this udev version on older kernels may cause a short delay for
113 o To provide infrastructure for persistent device naming, the id programs:
114 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
115 to export the probed data in environment key format:
116 pim:~ # /sbin/ata_id --export /dev/hda
117 ID_MODEL=HTS726060M9AT00
118 ID_SERIAL=MRH401M4G6UM9B
122 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
123 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
126 kay@pim:~> tree /dev/disk
129 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
130 | `-- IBM-Memory_Key -> ../../sda
132 | |-- swap -> ../../hda1
133 | |-- date -> ../../sda1
134 | `-- home -> ../../hda3
136 |-- 2E08712B0870F2E7 -> ../../hda3
137 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
138 |-- E845-7A89 -> ../../sda1
139 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
141 The IMPORT= operation will import these keys in the environment and make
142 it available for later PROGRAM= and RUN= executed programs. The keys are
143 also stored in the udevdb and can be queried from there with one of the
146 o A few binaries are silently added to the repository, which can be used
147 to replay kernel events from initramfs instead of using coldplug. udevd
148 can be instructed now to queue-up events while the stored events from
149 initramfs are filled into the udevd-queue. This code is still under
150 development and there is no documentation now besides the code itself.
151 The additional binaries get compiled, but are not installed by default.
153 o There is also a temporary fix for a performance problem where too many
154 events happen in parallel and every event needs to parse the rules.
155 udev can now read precompiled rules stored on disk. This is likely to be
156 replaced by a more elegant solution in a future udev version.
160 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
161 Fix for libsysfs not to expect this file was added.
165 All rules are applied now, but only the first matching rule with a NAME-key
166 will be applied. All later rules with NAME-key are completely ignored. This
167 way system supplied symlinks or permissions gets applied to user-defined
171 Please check your rules setup, if you may need to add OPTIONS="last_rule"
172 to some rules, to keep the old behavior.
174 The rules are read on "remove"-events too. That makes is possible to match
175 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
176 instruct udev to ignore an event (OPTIONS="ignore_device").
177 The new ACTION-key may be used to let a rule act only at a "remove"-event.
179 The new RUN-key supports rule-based execution of programs after device-node
180 handling. This is meant as a general replacement for the dev.d/-directories
181 to give fine grained control over the execution of programs.
183 The %s{}-sysfs format char replacement values are searched at any of the
184 devices in the device chain now, not only at the class-device.
186 We support log priority levels now. The value udev_log in udev.conf is used
187 to determine what is printed to syslog. This makes it possible to
188 run a version with compiled-in debug messages in a production environment
189 which is sometimes needed to find a bug.
190 It is still possible to supress the inclusion of _any_ syslog usage with
191 USE_LOG=false to create the smallest possible binaries if needed.
192 The configured udev_log value can be overridden with the environment variable
197 Possible use of a system-wide klibc:
198 make USE_KLIBC=true KLCC=/usr/bin/klcc all
199 will link against an external klibc and our own version will be ignored.
203 We support an unlimited count of symlinks now.
205 If USE_STATIC=true is passed to a glibc build, we link statically and use
206 a built-in userdb parser to resolve user and group names.
208 The PLACE= key is gone. It can be replaced by an ID= for a long time, cause
209 we walk up the chain of physical devices to find a match.
211 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
212 easy to skip certain attribute matches without composing rules with weird
213 character class negations like:
214 KERNEL="[!s][!c][!d]*"
215 this can now be replaced with:
217 The current simple '=' is still supported, and should work as it does today,
218 but existing rules should be converted if possible, to be better readable.
220 We have new ENV{}== key now, to match against a maximum of 5 environment
223 udevstart is its own binary again, cause we don't need co carry this araound
224 with every forked event.