X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=README;h=581e84598e7d14ec6ba130363fee2e00278b37a6;hp=00acf97c27e5405b5974a4c373b80f8113e17767;hb=0d6ce9236f61cb991d7e8f2359d818e41ead0cf5;hpb=65e9e8c5e8de192b2b6eea0dcb6089268eb9ad2a diff --git a/README b/README index 00acf97c2..581e84598 100644 --- a/README +++ b/README @@ -1,91 +1,122 @@ -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) (optional) + libkmod >= 5 (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) + sulogin (from util-linux >= 2.22 or sysvinit-tools, optional but recommended) + dracut (optional) + + When building from git you need the following additional dependencies: + + docbook-xsl + xsltproc + automake + autoconf + libtool + intltool + gperf + gtkdocize (optional) + python (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 offers professional + engineering and consulting services for systemd for embedded + and other use. Please contact Gustavo Barbieri + 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.