-udev - userspace device management
-
-For more information see the files in the docs/ directory.
-
-Important Note:
- 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:
- - Version 2.6.18 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, unix domain sockets and networking enabled.
- (unix domain sockets (CONFIG_UNIX) as a loadable kernel module may work,
- but it does not make any sense - 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 locations are supported by udev.
-
-
-Operation:
- Udev creates and removes device nodes in /dev, based on events the kernel
- sends out on device discovery or removal.
-
- - 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.
-
- - The content of /lib/udev/devices directory which contains the nodes,
- symlinks and directories, which are always expected to be in /dev, should
- be copied over to the tmpfs mounted /dev, to provide the required nodes
- to initialize udev and continue booting.
-
- - 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.
-
- - 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
- processing to load required kernel modules and setup devices. For all
- devices the kernel exports a major/minor number, udev will create a
- device node with the default kernel name, or the one specified by a
- matching udev rule.
-
-
-Compile Options:
- DESTDIR
- Prefix of install target, used for package building.
- USE_LOG
- If set to 'true', udev is able to pass errors or debug information
- to syslog. This is very useful to see what udev is doing or not doing.
- It is enabled by default, don't expect any useful answer, if you
- need to hunt a bug, but you can't enable syslog.
- DEBUG
- If set to 'true', very verbose debugging messages will be compiled
- into the udev binaries. The actual level of debugging is specified
- in the udev config file.
- USE_SELINUX
- If set to 'true', udev will be built with SELinux support
- enabled. This is disabled by default.
- EXTRAS
- list of helper programs in extras/ to build.
- make EXTRAS="extras/cdrom_id extras/scsi_id extras/volume_id"
-
-
-Installation:
- - The install target intalls the udev binaries in the default locations,
- All binaries will be installed in /lib/udev or /sbin.
-
- - The default location for scripts and binaries that are called from
- rules is /lib/udev. Other packages who install udev rules, may use
- that directory too.
-
- - It is recommended to use the /lib/udev/devices/ directory to place
- device nodes and symlinks in, which are copied to /dev at every boot.
- That way, nodes for broken subsystems or devices which can't be
- detected automatically by the kernel, will always be available.
-
- - Default udev rules and persistent device naming rules are required by other
- software that depends on the data udev collects from the devices,
- 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@vger.kernel.org
-
+systemd System and Service Manager
+
+DETAILS:
+ http://0pointer.de/blog/projects/systemd.html
+
+WEB SITE:
+ http://www.freedesktop.org/wiki/Software/systemd
+
+GIT:
+ git://anongit.freedesktop.org/systemd/systemd
+ ssh://git.freedesktop.org/git/systemd/systemd
+
+GITWEB:
+ http://cgit.freedesktop.org/systemd/systemd
+
+MAILING LIST:
+ http://lists.freedesktop.org/mailman/listinfo/systemd-devel
+ http://lists.freedesktop.org/mailman/listinfo/systemd-commits
+
+IRC:
+ #systemd on irc.freenode.org
+
+BUG REPORTS:
+ https://bugs.freedesktop.org/enter_bug.cgi?product=systemd
+
+AUTHOR:
+ Lennart Poettering
+ Kay Sievers
+ ...and many others
+
+LICENSE:
+ LGPLv2.1+ for all code
+ - except sd-daemon.[ch] and sd-readahead.[ch] which are MIT
+ - except src/udev/ which is GPLv2.0+
+
+REQUIREMENTS:
+ Linux kernel >= 2.6.39
+ with devtmpfs
+ with cgroups (but it's OK to disable all controllers)
+ optional but strongly recommended: autofs4, ipv6
+ dbus >= 1.4.0
+ libcap
+ libblkid >= 2.20 (from util-linux)
+ libkmod >= 5
+ PAM >= 1.1.2 (optional)
+ libcryptsetup (optional)
+ libgcrypt (optional)
+ libaudit (optional)
+ libacl (optional)
+ libattr (optional)
+ libselinux (optional)
+ liblzma (optional)
+ tcpwrappers (optional)
+ libgcrypt (optional)
+ libqrencode (optional)
+ libmicrohttpd (optional)
+
+ When you build from git you need the following additional dependencies:
+
+ docbook-xsl
+ xsltproc
+ automake
+ autoconf
+ libtool
+ intltool
+ gperf
+ gtkdocize (optional)
+ python (optional)
+ make, gcc, and similar tools
+
+ During runtime you need the following dependencies:
+
+ util-linux > v2.18 (requires fsck -l, agetty -s)
+ sulogin (from sysvinit-tools, optional but recommended)
+ dracut (optional)
+
+ When systemd-hostnamed is used it is strongly recommended to
+ install nss-myhostname to ensure that in a world of
+ dynamically changing hostnames the hostname stays resolvable
+ under all circumstances. In fact, systemd-hostnamed will warn
+ if nss-myhostname is not installed. Packagers are encouraged to
+ add a dependency on nss-myhostname to the package that
+ includes systemd-hostnamed.
+
+ Note that D-Bus can link against libsystemd-login.so, which
+ results in a cyclic build dependency. To accommodate for this
+ please build D-Bus without systemd first, then build systemd,
+ then rebuild D-Bus with systemd support.
+
+WARNINGS:
+ systemd will warn you during boot if /etc/mtab is not a
+ symlink to /proc/mounts. Please ensure that /etc/mtab is a
+ proper symlink.
+
+ systemd will warn you during boot if /usr is on a different
+ file system than /. While in systemd itself very little will
+ break if /usr is on a separate partition many of its
+ dependencies very likely will break sooner or later in one
+ form or another. For example udev rules tend to refer to
+ binaries in /usr, binaries that link to libraries in /usr or
+ binaries that refer to data files in /usr. Since these
+ breakages are not always directly visible systemd will warn
+ about this, since this kind of file system setup is not really
+ supported anymore by the basic set of Linux OS components.
+
+ For more information on this issue consult
+ http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken
+
+ To run systemd under valgrind, compile with VALGRIND defined
+ (e.g. ./configure CPPFLAGS='... -DVALGRIND=1'). Otherwise,
+ false positives will be triggered by code which violates
+ some rules but is actually safe.
+
+ENGINEERING AND CONSULTING SERVICES:
+ ProFUSION <http://profusion.mobi> offers professional
+ engineering and consulting services for systemd for embedded
+ and other use. Please contact Gustavo Barbieri
+ <barbieri@profusion.mobi> for more information.
+
+ Disclaimer: This notice is not a recommendation or official
+ endorsement. However, ProFUSION's upstream work has been very
+ beneficial for the systemd project.
~ianmdlvl / elogind.git / blobdiff