X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=README;h=148217d16a3e1b9f59e2612e5df053aa4669ab85;hp=6aabf69f8a21376eded9e31e1bc12fa636dfb284;hb=c99b72121fb965920652ea5e7a1d7f962385626b;hpb=47d9121c9a6a6d4d3415e6a012ebbb3256440a65 diff --git a/README b/README index 6aabf69f8..148217d16 100644 --- a/README +++ b/README @@ -7,7 +7,7 @@ does not recommend replacing a distro's udev installation with the upstream version. The upstream udev project's set of default rules may require a most recent -kernel release to work properly. This is currently version 2.6.31. +kernel release to work properly. This is currently version 2.6.32. 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 @@ -16,8 +16,13 @@ by udevadm and libudev. Tools and rules in /lib/udev and the entire contents of the /dev/.udev directory are private to udev and do change whenever needed. Requirements: - - Version 2.6.27 of the Linux kernel with sysfs, procfs, signalfd, inotify, - unix domain sockets, networking and hotplug enabled: + - Version 2.6.34 of the Linux kernel with sysfs, procfs, signalfd, inotify, + unix domain sockets, networking and hotplug enabled + + - Some architectures might need a later kernel, that supports accept4(), + or need to backport the accept4() syscall wiring in the kernel. + + - These options are needed: CONFIG_HOTPLUG=y CONFIG_UEVENT_HELPER_PATH="" CONFIG_NET=y @@ -25,9 +30,11 @@ Requirements: CONFIG_SYSFS=y CONFIG_SYSFS_DEPRECATED*=n CONFIG_PROC_FS=y - CONFIG_TMPFS=y CONFIG_INOTIFY_USER=y CONFIG_SIGNALFD=y + + - These options might be needed: + CONFIG_TMPFS=y CONFIG_TMPFS_POSIX_ACL=y (user ACLs for device nodes) CONFIG_BLK_DEV_BSG=y (SCSI devices) @@ -45,15 +52,15 @@ Requirements: be mounted at /sys. No other locations are supported by a standard udev installation. - - The system must have the following group names resolvable at udev startup: + - The default rule sset requires the following group names resolvable at udev startup: disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, and kmem. Especially in LDAP setups, it is required that getgrnam() be 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, - and gperf are needed. These dependencies can be disabled with the - --disable-extras configure option. + - Some udev extras have external dependencies like: + libacl, libglib2, libusb, usbutils, pciutils, and gperf. + All these extras can be disabled with configure options. Setup: - At bootup, the /dev directory should get the 'devtmpfs' filesystem @@ -64,22 +71,22 @@ Setup: - The udev daemon should be started to handle device events sent by the kernel. During bootup, the kernel can be asked to send events for all already existing - devices, to apply the configuration to these devices. This is usually done by: + devices so that they too can be configured by udev. This is usually done by: /sbin/udevadm trigger --type=subsystems /sbin/udevadm trigger --type=devices - - Restarting the daemon does never apply any rules to existing devices. + - Restarting the daemon never applies any rules to existing devices. - New/changed rule files are picked up automatically; there is no daemon restart or signal needed. Operation: - - Udev creates/removes device nodes in /dev, based on events the kernel - sends out on device creation/removal. + - Based on events the kernel sends out on device creation/removal, udev + creates/removes device nodes in the /dev directory. - All kernel events are matched against a set of specified rules, which possibly hook into the event processing and load required kernel - modules to setup devices. For all devices the kernel exports a major/minor + modules to set up devices. For all devices, the kernel exports a major/minor number; if needed, udev creates a device node with the default kernel name. If specified, udev applies permissions/ownership to the device node, creates additional symlinks pointing to the node, and executes @@ -90,7 +97,8 @@ Operation: http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/ http://www.kernel.org/pub/linux/utils/kernel/hotplug/gudev/ -For more details about udev and udev rules see the udev(7) man page. +For more details about udev and udev rules, see the udev man pages: + http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev/ Please direct any comment/question to the linux-hotplug mailing list at: linux-hotplug@vger.kernel.org