For more information see the files in the docs/ directory.
Important Note:
- Integrating udev in the system is a whole lot of work, has complex dependencies
- and differs a lot from distro to distro. All major distros depend on udev these
- days and the system may not work without a proper installed version. The upstream
- udev project does not support or recomend to replace a distro's udev installation
- with the upstream version. The installation of a unmodified upstream version may
- render your system unusable. Until now, there is no "default" setup or a set of
- "default" rules provided by the upstream udev version.
+ Integrating udev in the system has complex dependencies and differs from distro
+ to distro. All major distros depend on udev these days and the system may not
+ work without a properly installed version. The upstream udev project does not
+ recommend to replace a distro's udev installation with the upstream version.
Requirements:
- - 2.6.x version of the Linux kernel. See the RELEASE-NOTES file in the
- udev tree and the Documentation/Changes in the kernel source tree for
- the actual dependency.
+ - Version 2.6.15 of the Linux kernel for reliable operation of this release of
+ udev. The kernel may have a requirement on udev too, see Documentation/Changes
+ in the kernel source tree for the actual dependency.
- - The kernel must have sysfs and unix domain socket enabled.
+ - The kernel must have sysfs, unix domain sockets and networking enabled.
(unix domain sockets (CONFIG_UNIX) as a loadable kernel module may work,
- but it is completely silly - don't complain if anything goes wrong.)
+ but it is completely silly - don't complain if anything goes wrong.)
- - The proc filesystem must be mounted on /proc.
-
- - The sysfs filesystem must be mounted at /sys. No other location
- will be supported by udev.
+ - The proc filesystem must be mounted on /proc, the sysfs filesystem must
+ be mounted at /sys. No other location is supported by udev.
Operation:
Udev creates and removes device nodes in /dev, based on events the kernel
sends out on device discovery or removal.
- - Early in the boot process, the /dev directory should get a tmpfs
+ - Very early in the boot process, the /dev directory should get a 'tmpfs'
filesystem mounted, which is populated from scratch by udev. Created nodes
or changed permissions will not survive a reboot, which is intentional.
be copied over to the tmpfs mounted /dev, to provide the required nodes
to initialize udev and continue booting.
- - The udevd daemon must be started by an init script to receive netlink
- uevents from the kernel driver core.
+ - The old hotplug helper /sbin/hotplug should be disabled on bootup, before
+ actions like loading kernel modules are taken, which may cause a lot of
+ events.
- - From kernel version 2.6.15 on, the hotplug helper /sbin/hotplug should
- be disabled with an init script before actions like loading kernel
- modules are taken, which may cause a lot of events.
+ - The udevd daemon must be started on bootup to receive netlink uevents
+ from the kernel driver core.
- All kernel events are matched against a set of specified rules in
/etc/udev/rules.d/ which make it possible to hook into the event
and should be installed by default with every udev installation.
Please direct any comment/question/concern to the linux-hotplug-devel mailing list at:
- linux-hotplug-devel@lists.sourceforge.net
+ linux-hotplug@vger.kernel.org
~ianmdlvl / elogind.git / blobdiff