X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=README;h=6b0eb51ecd7c0bfa107a4f44cce04f46077b0ed6;hp=a2f00021e8b58e57fd0c1239244c6bf9ab9e49bd;hb=64661ee70d5a10c6208a1cb66ecd8b158e2d8bc5;hpb=0f50d0ef04feecfb33ac7dd7a38300679c3ed27d diff --git a/README b/README index a2f00021e..6b0eb51ec 100644 --- a/README +++ b/README @@ -1,74 +1,104 @@ -udev - userspace device management - -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. - -Tools and rules shipped by udev are not public API and may change at any time. -Never call any private tool in /lib/udev from any external application, it might -just go away in the next release. Access to udev information is only offered -by udevadm and libudev. Everything in /lib/udev and /dev/.udev/ is 100% private -to udev. - -Requirements: - - Version 2.6.25 of the Linux kernel with sysfs, procfs, signalfd, inotify, - unix domain sockets, networking and hotplug enabled: - CONFIG_HOTPLUG=y - CONFIG_UEVENT_HELPER_PATH="" - CONFIG_NET=y - CONFIG_UNIX=y - CONFIG_SYSFS=y - CONFIG_SYSFS_DEPRECATED*=n - CONFIG_PROC_FS=y - CONFIG_TMPFS=y - CONFIG_TMPFS_POSIX_ACL=y - CONFIG_INOTIFY=y - CONFIG_SIGNALFD=y - - - For reliable operation, the kernel must not use the CONFIG_SYSFS_DEPRECATED* - option. - - - Unix domain sockets (CONFIG_UNIX) as a loadable kernel module is not - supported. - - - The proc filesystem must be mounted on /proc/, the sysfs filesystem must - be mounted at /sys/. No other locations are supported by udev. - - - The system must have the following group names resolvable at udev startup: - disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem. - Especially in LDAP setups, it is required, that getgrnam() is able to resolve - these group names with only the rootfs mounted, and while no network is - available. - - - To build all udev extras, libacl, libglib2, libusb, usbutils, pciutils, - gperf are needed. These dependencies can be disabled with the - --disable-extras option. - -Operation: - Udev creates and removes device nodes in /dev/, based on events the kernel - sends out on device discovery or removal. - - - Early in the boot process, the /dev/ directory should get a 'tmpfs' - filesystem mounted, which is maintained 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 in the kernel - configuration, it is not needed, and may render the system unusable - because of a fork-bombing behavior. - - - All kernel events are matched against a set of specified rules in - /lib/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. - -Please direct any comment/question/concern to the linux-hotplug 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 with major support from Kay Sievers + +LICENSE: + GPLv2+ for all code, except sd-daemon.[ch] and + sd-readahead.[ch] which are MIT + +REQUIREMENTS: + Linux kernel >= 2.6.39 + with devtmpfs + with cgroups (but it's OK to disable all controllers) + optional but strongly recommended: autofs4, ipv6 + libudev >= 172 + 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 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.