Linux From Scratch - Version 20200613-cross2

Chapter 8. Installing Basic System Software

8.67. Eudev-3.2.9

The Eudev package contains programs for dynamic creation of device nodes.

Approximate build time: 0.2 SBU
Required disk space: 82 MB

8.67.1. Installation of Eudev

Prepare Eudev for compilation: 

./configure --prefix=/usr           \
            --bindir=/sbin          \
            --sbindir=/sbin         \
            --libdir=/usr/lib       \
            --sysconfdir=/etc       \
            --libexecdir=/lib       \
            --with-rootprefix=      \
            --with-rootlibdir=/lib  \
            --enable-manpages       \
            --disable-static

Compile the package: 

make

Create some directories now that are needed for tests, but will also be used as a part of installation: 

mkdir -pv /lib/udev/rules.d
mkdir -pv /etc/udev/rules.d

To test the results, issue: 

make check

Install the package: 

make install

Install some custom rules and support files useful in an LFS environment: 

tar -xvf ../udev-lfs-20171102.tar.xz
make -f udev-lfs-20171102/Makefile.lfs install

8.67.2. Configuring Eudev

Information about hardware devices is maintained in the /etc/udev/hwdb.d and /lib/udev/hwdb.d directories. Eudev needs that information to be compiled into a binary database /etc/udev/hwdb.bin. Create the initial database: 

udevadm hwdb --update

This command needs to be run each time the hardware information is updated.

8.67.3. Contents of Eudev

Installed programs: udevadm and udevd
Installed libraries: libudev.so
Installed directories: /etc/udev, /lib/udev, and /usr/share/doc/udev-udev-lfs-20171102

Short Descriptions

udevadm

Generic udev administration tool: controls the udevd daemon, provides info from the Udev database, monitors uevents, waits for uevents to finish, tests Udev configuration, and triggers uevents for a given device

udevd

A daemon that listens for uevents on the netlink socket, creates devices and runs the configured external programs in response to these uevents

libudev

A library interface to udev device information

/etc/udev

Contains Udev configuration files, device permissions, and rules for device naming