mirror of
https://github.com/systemd/systemd-stable.git
synced 2024-10-30 23:21:08 +03:00
69 lines
2.7 KiB
Plaintext
69 lines
2.7 KiB
Plaintext
udev - userspace device management
|
|
|
|
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 reasonable distros use udev these
|
|
days, the major ones make it mandatory and the system will not work without it.
|
|
|
|
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! There is no "default" setup or a set
|
|
of "default" rules provided by the upstream udev version.
|
|
|
|
udev requires:
|
|
- 2.6 version of the Linux kernel
|
|
|
|
- the kernel must have sysfs, netlink, and hotplug enabled
|
|
|
|
- proc must be mounted on /proc
|
|
|
|
- sysfs must be mounted at /sys, no other location is supported
|
|
|
|
- udev creates and removes device nodes in /dev based on events
|
|
the kernel sends out on device discovery or removal
|
|
|
|
- during bootup /dev usually gets a tmpfs mounted which is populated scratch
|
|
by udev (created nodes don't survive a reboot, it always starts from scratch)
|
|
|
|
- udev replaces the hotplug event management invoked from /sbin/hotplug
|
|
by the udevd daemon, which receives the kernel events over netlink
|
|
|
|
- all kernel events are matched against a set of specified rules which
|
|
make it posible to hook into the event processing
|
|
|
|
- there is a copy of the rules files for all major distros in the etc/udev
|
|
directory (you may look there how others distros are doing it)
|
|
|
|
Setting which are used for building udev:
|
|
prefix
|
|
set this to the default root that you want to use
|
|
Only override this if you really know what you are doing
|
|
DESTDIR
|
|
prefix for install target for package building
|
|
USE_LOG
|
|
if set to 'true', udev will emit messages to the syslog when
|
|
it creates or removes device nodes. This is helpful to see
|
|
what udev is doing. This is enabled by default.
|
|
DEBUG
|
|
if set to 'true', verbose debugging messages will be compiled into
|
|
the udev binaries. Default value is 'false'.
|
|
USE_SELINUX
|
|
if set to 'true', udev will be built with SELinux support
|
|
enabled. This is disabled by default.
|
|
USE_KLIBC
|
|
if set to 'true', udev is built and linked against klibc.
|
|
Default value is 'false'. KLCC specifies the klibc compiler
|
|
wrapper, usually in /usr/bin/klcc
|
|
EXTRAS
|
|
if set, will build the "extra" helper programs as specified
|
|
as listed (see below for an example.)
|
|
|
|
if you want to build the udev helper program cdrom_id and scsi_id:
|
|
make EXTRAS="extras/cdrom_id extras/scsi_id"
|
|
|
|
Please direct any comment/question/concern to the linux-hotplug-devel mailing list at:
|
|
linux-hotplug-devel@lists.sourceforge.net
|
|
|