-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. Note, if you
- are building udev against klibc it is recommended that you
- disable this option (due to klibc's syslog implementation.)
- 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 the
- included version of klibc. Default value is 'false'.
- KERNEL_DIR
- If this is not set it will default to /lib/modules/`uname -r`/build
- This is used if USE_KLIBC=true to find the kernel include
- directory that klibc needs to build against. This must be set
- if you are not building udev while running a 2.6 kernel.
- EXTRAS
- if set, will build the "extra" helper programs as specified
- as listed (see below for an example.)
-
-if you want to build udev using klibc with debugging messages:
- make USE_KLIBC=true DEBUG=true
-
-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
-
+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
+ PAM >= 1.1.2 (optional)
+ libcryptsetup (optional)
+ libaudit (optional)
+ libselinux (optional)
+ tcpwrappers (optional)
+
+ When you build from git you need the following additional dependencies:
+
+ docbook-xsl
+ xsltproc
+ automake
+ autoconf
+ libtool
+ gperf
+ 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)
+ plymouth (optional)
+ 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 resolveable
+ 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 accomodate 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
+
+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.