-udev - a userspace implementation of devfs
+udev - a userspace device manager
For more information on the design, and structure of this project, see the
files in the docs/ directory.
To use:
-- Edit the udev.h file and replace the following variables with values
- that make sense for your system:
- #define SYSFS_ROOT "/sys"
- #define UDEV_ROOT "/home/greg/linux/udev/"
- #define DEV_FILE "/dev"
- #define MKNOD "/bin/mknod"
- The only value most people will have to change is the UDEV_ROOT
- variable, as I doubt you really want device nodes to be created in my
- home directory :)
+- You must be running a 2.6 version of the Linux kernel.
-- Run make to build the project.
+- Your 2.6 kernel must have had CONFIG_HOTPLUG enabled when it was built.
-- Make sure sysfs is mounted.
+- Make sure sysfs is mounted at /sys. No other location is supported.
+ You can mount it by running:
+ mount -t sysfs none /sys
-- Point /proc/sys/kernel/hotplug at the location of the udev binary that
- is created. Then plug some block devices in, or other types of
- devices that create dev files in sysfs. An easy way to do this,
- without any hardware is to use the scsi_debug module to create virtual
- scsi devices.
+- Make sure you integrate udev with your hotplug setup. There is a copy of
+ the rules files for all major distros in the etc/udev folder. You may look
+ there how others are doing it.
-- Watch as the nodes get created and removed.
+- Make sure you integrate with the kernel hotplug events. Later versions of
+ udev are able to listen directly to a netlink socket, older versions used
+ udevsend to feed the udev daemon with the kernel event. The most basic
+ setup to run udev is to let the kernel for the udev binary directly:
+ echo "/sbin/udev" > /proc/sys/kernel/hotplug
+ While this may work in some setups, it is not recommended to do. A recent
+ kernel and udev version is able to operate with the event serializing daemon
+ udevd, that makes sure, that no "remove" event will beat a "add" event for
+ the same device.
-Yes this is a really rough first cut, I know. It's mostly a proof of
-concept that this can actually work. See the TODO file for a list of
-things left to be done.
+- Build the project:
+ make
-Any comment/questions/concerns please let me know.
+ Note:
+ There are a number of different flags that you can use when building
+ udev. They are as follows:
+ prefix
+ set this to the default root that you want udev to be
+ installed into. This works just like the 'configure --prefix'
+ script does. Default value is ''. Only override this if you
+ really know what you are doing.
+ USE_KLIBC
+ if set to 'true', udev is built and linked against the
+ included version of klibc. Default value is 'false'.
+ USE_LOG
+ if set to 'true', udev will emit messages to the syslog when
+ it creates or removes device nodes. This is helpful to see
+ what udev is doing. This is enabled by default. Note, if you
+ are building udev against klibc it is recommended that you
+ disable this option (due to klibc's syslog implementation.)
+ USE_SELINUX
+ if set to 'true', udev will be built with SELinux support
+ enabled. This is disabled by default.
+ DEBUG
+ if set to 'true', debugging messages will be sent to the syslog
+ as udev is run. Default value is 'false'.
+ KERNEL_DIR
+ If this is not set it will default to /lib/modules/`uname -r`/build
+ This is used if USE_KLIBC=true to find the kernel include
+ directory that klibc needs to build against. This must be set
+ if you are not building udev while running a 2.6 kernel.
+
+ So, if you want to build udev using klibc with debugging messages, you
+ would do:
+ make USE_KLIBC=true DEBUG=true
+
+ udev will follow the setting of the debug level in udev.conf. Adapt this
+ value to see the debug in syslog.
+
+- Install the project:
+ make install
+
+ This will put the udev binaries in /sbin, create the and /etc/udev
+ directories, and place the udev configuration files in /etc/udev/. You
+ will probably want to edit the *.rules files to create custom naming
+ rules. More info on how the config files are set up are contained in
+ comments in the files, and is located in the documentation.
+
+- Add and remove devices from the system and marvel as nodes are created
+ and removed in /dev based on the device types.
+
+- If you later get sick of it, uninstall it:
+ make uninstall
+
+If nothing seems to happen, make sure your build worked properly by
+running the udev-test.pl script as root in the test/ subdirectory of the
+udev source tree.
+
+Development and documentation help is very much appreciated, see the TODO
+file for a list of things left to be done.
+
+Any comment/questions/concerns please let me and the other udev developers
+know by sending a message to the linux-hotplug-devel mailing list at:
+ linux-hotplug-devel@lists.sourceforge.net
greg k-h
greg@kroah.com
+
~ianmdlvl / elogind.git / blobdiff