#!/bin/sh
# $Id$

# loads given kernel modules
load_kernel_modules()
{
	local type="$1"
	local module
	local args
	
	echo -e "-- Loading ${type} modules:"
	( cat /etc/modules.${type}; echo) | while read module args
	do
		case "${module}" in
			\#*|"") continue ;;
		esac

		if [ -e /lib/${module}.ko ]
		then
			insmod -f /lib/${module}.ko ${args} > /dev/null 2>&1
			[ $? -eq 0 ] && echo -e "--      ${module}"
		fi
	done
	echo
}

# check_drives $devices $fstype
check_drives()
{
	local devices="$1"
	local fs="$2"

	for dev in ${devices}
	do
		mount -t ${fs} ${dev} /sysroot/mnt/cdrom >/dev/null 2>&1
		media_found=$?

		# if mount was ok check if cdid exists
		if [ "${media_found}" -eq 0 ]
		then
			[ -e /sysroot/mnt/cdrom/livecdrootfs.sqsh ] && media_id_ok=$?
			umount /sysroot/mnt/cdrom
	
			if [ "${media_id_ok}" -eq 0 ]
			then
				echo -e "Magellan boot device found."
				BOOT_DEVICE="${dev}"
				FSTYPE="${fs}"
				break
			fi
		fi
	done
}

## some defaults ##
DOSCSI=no
DOUSB=no
DOSATA=yes
DOFB=no
DOPATA=yes
FORCED_ROOTFS=""
INITEXEC="/sbin/init"
BREAK_ENABLED=no
UNIONFS=no
UNIONFS_FILE=""
CLOOPMOUNTDIR="/sysroot/mnt/cloop"

## starts here ##

# mount essential filesystems
mount -t proc proc /proc
mount -t sysfs sysfs /sys
mount -t tmpfs tmpfs /dev -o rw,mode=0644,size=1024

# install all busybox applets
busybox --install -s

# silencio
echo 0 > /proc/sys/kernel/printk

# check command line for params
for i in $(cat /proc/cmdline)
do
	case "${i}" in
		doscsi) DOSCSI=yes;;
		noscsi) DOSCSI=no;;
		dousb) DOUSB=yes;;
		nousb) DOUSB=no;;
		dosata) DOSATA=yes ;;
		nosata) DOSATA=no ;;
		dofb) DOFB=yes;;
		nofb) DOFB=no;;
		dopata) DOPATA=yes;;
		nopata) DOPATA=no;;
		rootfs=*) FORCED_ROOTFS="${i#*=}";;
		init=*) INITEXEC="${i#*=}";;
		break) BREAK_ENABLED=yes ;;
		unionfs) UNIONFS=yes;;
		unionfs_file=*) UNIONFS_FILE="${i#*=}";;
		rootdelay=*) ROOTDELAY="${i#*=}";;
	esac
done

# now load all needed modules
[ "${DOFB}" = "yes" ] && load_kernel_modules "framebuffer"
load_kernel_modules "generic"
[ "${DOPATA}" = "yes" ] && load_kernel_modules "pata"
[ "${DOSCSI}" = "yes" ] && load_kernel_modules "scsi"
[ "${DOUSB}" = "yes" ] && load_kernel_modules "usb"
[ "${DOSATA}" = "yes" ] && load_kernel_modules "sata"

# populate dev
mdev -s
# handle hotplug events properly
echo /sbin/mdev > /proc/sys/kernel/hotplug

# create newroot mount point
mkdir -p /sysroot
# fake a new filesystem (also needed with an initramfs!!)
mount -t tmpfs tmpfs /sysroot

mkdir -p /sysroot/mnt/cdrom
mkdir -p /sysroot/mnt/cloop
mkdir -p /sysroot/mnt/magellan


# needed for the usbstick, the timeout maybe to short
if [ "${DOUSB}" = "yes" ]; then
	echo "-- Waiting 8 seconds for possible usb mount ..."
	sleep 8
fi

# respect rootdelay kernel param
if [ ! -z "${ROOTDELAY}" ]; then
	echo "-- Requested a rootdelay of ${ROOTDELAY} seconds ..."
	sleep ${ROOTDELAY}
fi

# searching cdrom with cdid
BOOT_DEVICE=""
FSTYPE=""

echo "Searching for a boot device ..."

# searching usbstick
if [ "${DOUSB}" = "yes" ]; then
	ROOTFS="vfat"
	[[ ! -z ${FORCED_ROOTFS} ]] && ROOTFS="${FORCED_ROOTFS}"
	check_drives "/dev/sd*" "${ROOTFS}"
	check_drives "/dev/sg*" "${ROOTFS}"
fi

# for cdrom_device in $CDROM_LIST (ide)
ROOTFS="iso9660"
[[ ! -z ${FORCED_ROOTFS} ]] && ROOTFS="${FORCED_ROOTFS}"
check_drives "/dev/cdroms/*" "${ROOTFS}"
check_drives "/dev/hd*" "${ROOTFS}"

# scsi cdroms
if [ "${DOSCSI}" = "yes" ] || [ "${DOSATA}" = "yes" ]; then
	ROOTFS="iso9660"
	[[ ! -z ${FORCED_ROOTFS} ]] && ROOTFS="${FORCED_ROOTFS}"
	check_drives "/dev/sr*" "${ROOTFS}"
	check_drives "/dev/sg*" "${ROOTFS}"
	check_drives "/dev/scd*" "${ROOTFS}"
fi

# mount our rootfs from cdrom
if [ "${BOOT_DEVICE}" = "" ]
then
	echo "No Magellan boot CD/USBStick found!!!"
	ash
	exit 1
else
	echo -e "Booting from: $BOOT_DEVICE ..."
	mount -o ro -t "${FSTYPE}" "${BOOT_DEVICE}" /sysroot/mnt/cdrom >/dev/null 2>&1

	# write our boot_device to /mnt/.bootdev for later use (mtab)
	echo "BOOTDEV=${BOOT_DEVICE}" > /sysroot/.bootdev
	echo "FSTYPE=${FSTYPE}" >> /sysroot/.bootdev

	# mount squashfs
	echo -e "Mounting squashfs system image ..."
	echo
	[ ! -e /dev/loop0 ] && mknod /dev/loop0 b 7 0
	mount -o loop,ro -t squashfs /sysroot/mnt/cdrom/livecdrootfs.sqsh "${CLOOPMOUNTDIR}"

	# mount unionfs if enabled
	if [[ ${UNIONFS} = yes ]]
	then
		echo -e "Mounting writeable cdbuffer (unionfs) ..."
	
		# default setting
		CLOOPMOUNTDIR="/sysroot/mnt/unionfs"
		[[ -z ${UNIONFS_FILE} ]] && UNIONFS_FILE="/sysroot/mnt/cdrom/unionfs"

		[[ ! -d /sysroot/mnt/unionfs ]] && install -d /sysroot/mnt/unionfs
		mount -t unionfs dirs=${UNIONFS_FILE}=rw:/sysroot/mnt/cloop=ro ${CLOOPMOUNTDIR}
	fi

	# symlinking cloop rootfs to /mnt as newroot
	cd /sysroot

	for x in bin sbin lib lib64 boot usr opt
	do
		[ -d ${CLOOPMOUNTDIR/\/sysroot\//}/${x} ] && ln -s ${CLOOPMOUNTDIR/\/sysroot\//}/${x} ${x}
	done
	mkdir -p initrd proc tmp sys var/tmp dev media

	# use devtmpfs if supported
	if [ "$(grep devtmpfs /proc/filesystems | cut -d$'\t' -f2)" = "devtmpfs" ]
	then
		mount -t devtmpfs dev /sysroot/dev
	else
		# make /sysroot/dev/console & /mnt/dev/null
		[ ! -e /sysroot/dev/console ] && mknod -m 600 /sysroot/dev/console c 5 1
		[ ! -e /sysroot/dev/null ] && mknod -m 666 /sysroot/dev/null c 1 3
		# only to be safe and to have a log channel
		[ ! -e /sysroot/dev/tty ] && mknod /sysroot/dev/tty c 5 0
		# busybox needs this one
		[ ! -e /sysroot/dev/tty5 ] && mknod /sysroot/dev/tty5 c 4 5
	fi

	(cd ${CLOOPMOUNTDIR}; cp -a etc root home var /sysroot)

	# ensure that /sysroot/linurc exists
	[ ! -e /sysroot/linuxrc ] && ln -snf ${INITEXEC} /sysroot/linuxrc

	# ensure the right permissions
	chmod 1777 /sysroot/tmp
	chmod 1777 /sysroot/var/tmp
fi

cd /

# unset hotplug event-manager
echo > /proc/sys/kernel/hotplug

# de-silencio
echo 3 > /proc/sys/kernel/printk

if [[ ${BREAK_ENABLED} = yes ]]
then
	echo "-- Break requested, type 'exit' to resume operation ..."
	ash
fi

echo "-- Switching to real sysroot ..."
umount /dev
umount /sys
umount /proc

exec run-init /sysroot ${INITEXEC} $@ </sysroot/dev/console >/sysroot/dev/console