The udev-lfs set of files is a customization of systemd.
In 2012, udev was merged with systemd and a build methodology
incompatible with LFS.  These files add cusom udev rules
for LFS.

These files are distributed in the form of a tar file available
from the LFS file mirrors.  The tarball is created with:

mkdir /tmp/udev-lfs-$VERSION
cp -av * /tmp/udev-lfs-$VERSION
tar -jcf /tmp/udev-lfs-$VERSION.tar.bz2 -C /tmp udev-lfs-$VERSION

Makefile.lfs         - The LFS Makefile.  Installs udev rules for LFS.

contrib              - Useful rules from debian
contrib/debian
contrib/debian/83-cdrom-symlinks.rules
contrib/debian/write_cd_aliases
contrib/debian/81-cdrom.rules

55-lfs.rules         - LFS custom rules
write_net_rules      - Scripts for LFS rules
write_cd_rules
rule_generator.functions

55-lfs.txt           - Documentation for LFS installed rules

ChangeLog            - Log of changes to 55-lfs-rules

init-net-rules.sh    - A script for establishing persistent network
                       rules before the first LFS boot