-
-udev - a userspace device manager
-
-For more information on the design, and structure of this project, see the
-files in the docs/ directory.
-
-To use:
-
-- You must be running a 2.6 version of the Linux kernel.
-
-- Your 2.6 kernel must have had CONFIG_HOTPLUG enabled when it was built.
-
-- Make sure sysfs is mounted at /sys. No other location is supported.
- You can mount it by running:
- mount -t sysfs none /sys
-
-- Make sure you integrate udev with your hotplug setup. There is a copy of
- the rules files for all major distros in the etc/udev folder. You may look
- there how others are doing it.
-
-- Make sure you integrate with the kernel hotplug events. Later versions of
- udev are able to listen directly to a netlink socket, older versions used
- udevsend to feed the udev daemon with the kernel event. The most basic
- setup to run udev is to let the kernel for the udev binary directly:
- echo "/sbin/udev" > /proc/sys/kernel/hotplug
-
- While this may work in some setups, it is not recommended to do. A recent
- kernel and udev version is able to operate with the event serializing daemon
- udevd, that makes sure, that no "remove" event will beat a "add" event for
- the same device.
-
-- Build the project:
- make
-
- Note:
- There are a number of different flags that you can use when building
- udev. They are as follows:
- prefix
- set this to the default root that you want udev to be
- installed into. This works just like the 'configure --prefix'
- script does. Default value is ''. Only override this if you
- really know what you are doing.
- USE_KLIBC
- if set to 'true', udev is built and linked against the
- included version of klibc. Default value is 'false'.
- 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.)
- USE_SELINUX
- if set to 'true', udev will be built with SELinux support
- enabled. This is disabled by default.
- DEBUG
- if set to 'true', debugging messages will be sent to the syslog
- as udev is run. 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.
-
- So, if you want to build udev using klibc with debugging messages, you
- would do:
- make USE_KLIBC=true DEBUG=true
-
- udev will follow the setting of the debug level in udev.conf. Adapt this
- value to see the debug in syslog.
-
-- Install the project:
- make install
-
- This will put the udev binaries in /sbin, create the and /etc/udev
- directories, and place the udev configuration files in /etc/udev/. You
- will probably want to edit the *.rules files to create custom naming
- rules. More info on how the config files are set up are contained in
- comments in the files, and is located in the documentation.
-
-- Add and remove devices from the system and marvel as nodes are created
- and removed in /dev based on the device types.
-
-- If you later get sick of it, uninstall it:
- make uninstall
-
-If nothing seems to happen, make sure your build worked properly by
-running the udev-test.pl script as root in the test/ subdirectory of the
-udev source tree. Running udevstart should populate an empty /dev
-directory. You may test, if a node is recreated after running udevstart.
-
-Development and documentation help is very much appreciated, see the TODO
-file for a list of things left to be done.
-
-Any comment/questions/concerns please let me and the other udev developers
-know by sending a message to the linux-hotplug-devel mailing list at:
- linux-hotplug-devel@lists.sourceforge.net
-
-greg k-h
-greg@kroah.com
-
+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/shared/MurmurHash3.c which is Public Domain
+ - except src/journal/lookup3.c which is Public Domain
+ - except src/udev/* which is (currently still) GPLv2, GPLv2+
+
+REQUIREMENTS:
+ Linux kernel >= 3.0
+ CONFIG_DEVTMPFS
+ CONFIG_CGROUPS (it's OK to disable all controllers)
+ CONFIG_INOTIFY_USER
+ CONFIG_SIGNALFD
+ CONFIG_TIMERFD
+ CONFIG_EPOLL
+ CONFIG_NET
+ CONFIG_SYSFS
+ CONFIG_PROC_FS
+
+ Linux kernel >= 3.8 for Smack support
+
+ Udev will fail to work with the legacy layout:
+ CONFIG_SYSFS_DEPRECATED=n
+
+ Legacy hotplug slows down the system and confuses udev:
+ CONFIG_UEVENT_HELPER_PATH=""
+
+ Userspace firmware loading is deprecated, will go away, and
+ sometimes causes problems:
+ CONFIG_FW_LOADER_USER_HELPER=n
+
+ Some udev rules and virtualization detection relies on it:
+ CONFIG_DMIID
+
+ Mount and bind mount handling might require it:
+ CONFIG_FHANDLE
+
+ Support for some SCSI devices serial number retrieval, to
+ create additional symlinks in /dev/disk/ and /dev/tape:
+ CONFIG_BLK_DEV_BSG
+
+ Optional but strongly recommended:
+ CONFIG_IPV6
+ CONFIG_AUTOFS4_FS
+ CONFIG_TMPFS_POSIX_ACL
+ CONFIG_TMPFS_XATTR
+ CONFIG_SECCOMP
+
+ For systemd-bootchart, several proc debug interfaces are required:
+ CONFIG_SCHEDSTATS
+ CONFIG_SCHED_DEBUG
+
+ For UEFI systems:
+ CONFIG_EFI_VARS
+ CONFIG_EFI_PARTITION
+
+ Note that kernel auditing is broken when used with systemd's
+ container code. When using systemd in conjunction with
+ containers, please make sure to either turn off auditing at
+ runtime using the kernel command line option "audit=0", or
+ turn it off at kernel compile time using:
+ CONFIG_AUDIT=n
+
+ glibc >= 2.14
+ libcap
+ libblkid >= 2.20 (from util-linux) (optional)
+ libkmod >= 15 (optional)
+ PAM >= 1.1.2 (optional)
+ libcryptsetup (optional)
+ libaudit (optional)
+ libacl (optional)
+ libattr (optional)
+ libselinux (optional)
+ liblzma (optional)
+ tcpwrappers (optional)
+ libgcrypt (optional)
+ libqrencode (optional)
+ libmicrohttpd (optional)
+ libpython (optional)
+ make, gcc, and similar tools
+
+ During runtime, you need the following additional
+ dependencies:
+
+ util-linux >= v2.19 (requires fsck -l, agetty -s),
+ v2.21 required for tests in test/
+ dbus >= 1.4.0 (strictly speaking optional, but recommended)
+ sulogin (from util-linux >= 2.22 or sysvinit-tools, optional but recommended,
+ required for tests in test/)
+ dracut (optional)
+ PolicyKit (optional)
+
+ When building from git, you need the following additional
+ dependencies:
+
+ docbook-xsl
+ xsltproc
+ automake
+ autoconf
+ libtool
+ intltool
+ gperf
+ gtkdocize (optional)
+ python (optional)
+ sphinx (optional)
+ python-lxml (entirely 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.
+
+ To build HTML documentation for python-systemd using sphinx,
+ please first install systemd (using 'make install'), and then
+ invoke sphinx-build with 'make sphinx-<target>', with <target>
+ being 'html' or 'latexpdf'. If using DESTDIR for installation,
+ pass the same DESTDIR to 'make sphinx-html' invocation.
+
+USERS AND GROUPS:
+ Default udev rules use the following standard system group
+ names, which need to be resolvable by getgrnam() at any time,
+ even in the very early boot stages, where no other databases
+ and network are available:
+
+ tty, dialout, kmem, video, audio, lp, floppy, cdrom, tape, disk
+
+ During runtime, the journal daemon requires the
+ "systemd-journal" system group to exist. New journal files will
+ be readable by this group (but not writable), which may be used
+ to grant specific users read access.
+
+ It is also recommended to grant read access to all journal
+ files to the system groups "wheel" and "adm" with a command
+ like the following in the post installation script of the
+ package:
+
+ # setfacl -nm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal/
+
+ The journal gateway daemon requires the
+ "systemd-journal-gateway" system user and group to
+ exist. During execution this network facing service will drop
+ privileges and assume this uid/gid for security reasons.
+
+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.