#! /bin/sh
#
# start_udev
# script to initialize /dev by using udev.
#
# Modified for Archlinux by Tobias Powalowski <tpowa@archlinux.org>
#
# Inspired by:
# 
# Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
#
# Released under the GPL v2 only.
#
# This needs to be run at the earliest possible point in the boot 
# process.
#
# Based on the udev init.d script
#
# Thanks go out to the Gentoo developers for proving 
# that this is possible to do.
#
# Yes, it's very verbose, feel free to turn off all of the echo calls,
# they were there to make me feel better that everything was working
# properly during development...
#

prog=udev
sysfs_dir=/sys
bin=/sbin/udev
udevd=/sbin/udevd
udev_root="/dev"

starttime=$(date +%s)


function trigger_builtin_events() {   
           list="$(echo /sys/class/tty/ttyS*/uevent)"   
           for i in $list; do   
               case "$i" in   
                   */class/uevent|*\**)   
                       continue   
                       ;;   
                   */class/tty/ttyS*)   
                       echo "add" > "$i"   
                       ;;   
               esac   
           done   
   }

function trigger_device_events() {
	/sbin/udevtrigger
}

function wait_for_queue() {
#	loop=20
#        while ! [ "$loop" -gt 0 -a -d /dev/.udev/queue ]; do
#                   sleep 0.1;
#                   loop=$(($loop - 1))
#        done
	/sbin/udevsettle
}

make_extra_nodes () {
	# there are a few things that sysfs does not export for us.
	# these things go here (and remember to remove them in 
	# remove_extra_nodes()
	#
	# Thanks to Gentoo for the initial list of these.
	ln -snf /proc/self/fd $udev_root/fd
	ln -snf /proc/self/fd/0 $udev_root/stdin
	ln -snf /proc/self/fd/1 $udev_root/stdout
	ln -snf /proc/self/fd/2 $udev_root/stderr
	ln -snf /proc/kcore $udev_root/core

	mkdir $udev_root/pts
	mkdir $udev_root/shm
}

udev_init  () {
# don't use udev if sysfs is not mounted.
if [ ! -d $sysfs_dir/block ]; then
	exit 1
fi

echo "mounting... ramfs at $udev_root"
mount -n -t ramfs none $udev_root

# propogate /udev from /sys
echo "Creating initial udev device nodes:"

#echo "making extra nodes"
make_extra_nodes

# check if udevd is already running
if [ `pidof -o %PPID /sbin/udevd` ]; then
	grep -v "/dev/shm" /etc/mtab | grep -v "/dev/pts" > /etc/mtab
	mount /dev/pts
	mount /dev/shm
else
	echo "start udev daemon"
	/sbin/udevd --daemon
fi
case "$(uname -r)" in
       2.6.[0-9]|2.6.[0-9][!0-9]*) ;;
       *) 	if [ -f "/sys/class/tty/console/uevent" ]; then
			echo "Kernel >= 2.6.15 and supports uevents"
			# trigger the sorted events
			echo -e '\000\000\000\000' > /proc/sys/kernel/hotplug
			# catch events that are real fast
			mkdir -p /dev/.udev/queue
			trigger_builtin_events
		else
			# for older kernels without uevents will be removed when udevstart dies in udev
			echo "Kernel does not support uevents, you need a kernel >= 2.6.15!"
			exit 1
		fi 
	;;
esac
}

udev_uevents () {
# configure all devices
trigger_device_events
# until we know how to do better, just wait for _all_ events to finish
wait_for_queue
}

if [ $# -eq 0 ]; then
udev_init
udev_uevents
fi

[ "$1" = "init" ] && udev_init
[ "$1" = "uevents" ] && udev_uevents

echo "udev startup is finished! - time = $(( `date +%s` - $starttime ))"
exit 0