shaba/systemd
1
0
Fork 0
mirror of https://github.com/systemd/systemd.git synced 2025-01-11 09:18:07 +03:00
Code

update README

Browse Source
This commit is contained in:
Kay Sievers 2011-09-18 17:58:13 +02:00
parent b93b46e4b7
commit afb9771b41
1 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
README
View File

@ -13,7 +13,7 @@ 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. Tools and rules in /lib/udev and the entire contents of
the /dev/.udev directory are private to udev and do change whenever needed.
the /run/udev directory are private to udev and do change whenever needed.
Requirements:
- Version 2.6.34 of the Linux kernel with sysfs, procfs, signalfd, inotify,
@ -59,21 +59,21 @@ Requirements:
available.
- Some udev extras have external dependencies like:
libacl, libglib2, libusb, usbutils, pciutils, and gperf.
libacl, libglib2, usbutils, pciutils, and gperf.
All these extras can be disabled with configure options.
Setup:
- At bootup, the /dev directory should get the 'devtmpfs' filesystem
mounted. Udev manages the permissions and ownership of the kernel-created
device nodes, and udev possibly creates additional symlinks. If needed, udev also
works on an empty 'tmpfs' filesystem, but some static device nodes like
/dev/null, /dev/console, /dev/kmsg are needed to be able to start udev itself.
works on an empty 'tmpfs' filesystem, but some device nodes like
/dev/null, /dev/console, /dev/kmsg should be created before udevd is started.
- 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 so that they too can be configured by udev. This is usually done by:
/sbin/udevadm trigger --type=subsystems
/sbin/udevadm trigger --type=devices
During bootup, the events for already existing devices can be replayed, so
that they are configured by udev. This is usually done by:
/sbin/udevadm trigger --action=add --type=subsystems
/sbin/udevadm trigger --action=add --type=devices
- Restarting the daemon never applies any rules to existing devices.
@ -82,13 +82,13 @@ Setup:
Operation:
- Based on events the kernel sends out on device creation/removal, udev
creates/removes device nodes in the /dev directory.
creates/removes device nodes and symlinks 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 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
device name. If specified, udev applies permissions/ownership to the device
node, creates additional symlinks pointing to the node, and executes
programs to handle the device.