#! /bin/sh
#
# start_udev
# script to initialize /dev by using udev.
#
# Modified for Archlinux by Tobias Powalowski <tpowa@archlinux.org>
#   Jan 16, 2006: Aaron Griffin <aaron@archlinux.org>
#                 Optimize trigger_device_events loop.
#
# 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...
#
# OpenSuse for the new uevents part

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

starttime=$(date +%s)

#AMG: The /sys/class/tty uevents are very large in number
#     (583/737 uevents on this machine).  Because this script
#     wants them to be triggered first, we'll trigger them
#     within the first therefore speeding up the ordering in
#     the second loop.  The order has been verified to be
#     identical to the previous method.  This has an added
#     benefit of starting the uevent triggering earlier.

#NOTE: Further speed may be gained by backgrounding the echo calls
#      with the possible introduction of race conditions.
function trigger_builtin_events() {
	list="$(echo /sys/class/*/*/uevent)"
	for i in $list; do
	    case "$i" in
		*/class/uevent|*\**)
		    continue
		    ;;
		*/class/mem/*|*/class/tty/*)
		    echo "add" > "$i"
		    ;;
	    esac
	done
}

function trigger_device_events() {
	list=$(echo /sys/bus/*/devices/*/uevent)
	list="$list $(echo /sys/class/*/*/uevent)"
	list="$list $(echo /sys/block/*/uevent /sys/block/*/*/uevent)"
	for i in $list; do
	    case "$i" in
		*/device/uevent|*\**)
		    continue
		    ;;
		*/block/md*)
		    last="$last $i"
		    ;;
		*/*)
		    default="$default $i"
		    ;;
	    esac
	done

	# trigger the sorted events
	for i in $default $last; do
	    echo "add" > "$i"
	done
}

function wait_for_queue() {
	loop=20
        while ! [ "$loop" -gt 0 -a -d /dev/.udev/queue ]; do
                sleep 0.1;
                loop=$(($loop - 1))
        done
	loop=200
	while [ "$loop" -gt 0 -a -d /dev/.udev/queue ]; do
		sleep 0.1;
		loop=$(($loop - 1))
	done
}

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 a 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