source: lsb-bootscripts/etc/init.d/udev@ b8d2a72

#!/bin/sh
# Begin $rc_base/init.d/udev

### BEGIN INIT INFO
# Provides:            udev
# Required-Start:
# Should-Start:        modules
# Required-Stop:
# Should-Stop:
# Default-Start:       S
# Default-Stop:
# Short-Description:   Populated /dev with device nodes.
# Description:         Mounts a tempfs on /dev and starts the udevd daemon.
#                      Device nodes are created as defined by udev.
# X-LFS-Provided-By:   LFS
### END INIT INFO

. /lib/lsb/init-functions

MESSAGE="Populating /dev with device nodes..."

case "${1}" in
        start)
                if ! grep -q '[[:space:]]sysfs' /proc/mounts; then
                        echo_failure
                        boot_mesg -n "FAILURE:\n\nUnable to create" ${FAILURE}
                        boot_mesg -n " devices without a SysFS filesystem"
                        boot_mesg -n "\n\nAfter you press Enter, this system"
                        boot_mesg -n " will be halted and powered off."
                        boot_mesg -n "\n\nPress Enter to continue..." ${INFO}
                        boot_mesg "" ${NORMAL}
                        $FAILURE_ACTION
                        /etc/rc.d/init.d/halt stop
                fi

                # If not using DEVTMPFS mount a temporary file system over
                # /dev, so that any devices made or removed during this boot
                # don't affect the next one. The reason we don't write to mtab
                # is because we don't ever want /dev to be unavailable (such as
                # by `umount -a').
                if ! mountpoint /dev > /dev/null; then
                        mount -n -t tmpfs tmpfs /dev -o mode=755
                fi
                if [ ${?} -ne 0 ]; then
                        echo_failure
                        boot_mesg -n "FAILURE:\n\nCannot mount a tmpfs" ${FAILURE}
                        boot_mesg -n " onto /dev, this system will be halted."
                        boot_mesg -n "\n\nAfter you press Enter, this system"
                        boot_mesg -n " will be halted and powered off."
                        boot_mesg -n "\n\nPress Enter to continue..." ${INFO}
                        boot_mesg "" ${NORMAL}
                        $FAILURE_ACTION
                        /etc/rc.d/init.d/halt stop
                fi

                # Create a symlink for POSIX shared memory
                ln -s /run/shm /dev/shm

                # Udev handles uevents itself, so we don't need to have
                # the kernel call out to any binary in response to them
                # This is a failsafe and should be done in kernel config
                echo > /proc/sys/kernel/hotplug

                # Copy the only static device node that Udev >= 155 doesn't
                # handle to /dev (handled by default with DEVTMPFS)
                if [ ! -f /dev/null ]; then
                        cp -a /lib/udev/devices/null /dev
                fi

                # Start the udev daemon to continually watch for, and act on,
                # uevents
                /sbin/udevd --daemon

                # Now traverse /sys in order to "coldplug" devices that have
                # already been discovered
                /sbin/udevadm trigger --action=add --type=subsystems
                /sbin/udevadm trigger --action=add --type=devices

                # Now wait for udevd to process the uevents we triggered
                /sbin/udevadm settle
                evaluate_retval standard
                ;;

        *)
                echo "Usage ${0} {start}"
                exit 1
                ;;
esac

# End $rc_base/init.d/udev