X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=README;h=3a511802eadbea08b3343c5303d938e4337e30aa;hp=773bc5508d3bdf513b29e622b9067789abf36b06;hb=514b8d62123e3d63f2b935aa1d58e5c411f3f603;hpb=67c89548d112e3d00ccdbad399720458b8289117 diff --git a/README b/README index 773bc5508..3a511802e 100644 --- a/README +++ b/README @@ -9,11 +9,24 @@ Important Note: recommend to replace a distro's udev installation with the upstream version. Requirements: - - Version 2.6.22 of the Linux kernel for reliable operation of this release of - udev. The kernel must not use the CONFIG_SYSFS_DEPRECATED* option. + - 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 - - The kernel must have sysfs, unix domain sockets and networking enabled. - Unix domain sockets (CONFIG_UNIX) as a loadable kernel module is not + - 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 @@ -25,25 +38,25 @@ Requirements: these group names with only the rootfs mounted, and while no network is available. + - To build all udev extras, libacl, libglib2, libusb, usbutils, pciutils 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. - - 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. + - 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 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. + - 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