#!/bin/sh

### cached kernel parameters :
#
# modprobe=
#         list of modules to load, example modprobe=r8169,btrfs
#
### Frugal mode or live CD : using a root ram disk.
#
# tmpram= [RAMDISK]
#         minimum % of free RAM to build the root tmpfs, default 100
#         a lower value may work, such as 50
# rootfssize= [RAMDISK]
#         size of / regarding the RAM size, default 90%
# rootfsinodes= [RAMDISK]
#         files count of / regarding the RAM size, default 0 (unlimited)
#
### Indirect mode ; an initramfs is used to mount root from the hard disk.
### Any rootfs should fit, minimum required is slitaz-base.
#
# mount= [MOUNT]
#         device with root loop file or sub directory
#   posixovl [MOUNT]
#         use posix attributes on a non posix filesystem (VFAT, NTFS...)
#   loopfs= [MOUNT]
#         loop file for root filesystem
#   subroot= [MOUNT]
#         sub directory for root filesystem
#     bindfs= [MOUNT] (deprecated)
#         bind out of root tree part
#
### Special disk mode ; needs extra modules/softwares from preinit flavor.
#
# dmraid= [RAID]
#         root semi hardware raid device name in /dev/mapper
# softraid= [RAID]
#         root software device name in /dev/mapper
# lvmroot= [LVM]
#         root logical volume name in /dev/mapper
# cryptoroot= [CRYPTO]
#         encrypted root device using luks or loop-aes
#
### Special mode used by loram flavor with aufs/overlayfs & squashfs
### incremental/nested rootfs (russian dolls).
#
# rodev= [LORAM][MERGE]
#         device (+ optional path) for the read only aufs branch
# rwdev= [LORAM][MERGE]
#         (persistent) device for the r/w aufs branch instead of the ramfs
# isofs [LORAM]
#         do not use squashfs filesystem images, but the cdrom filesystem only


fail() {
	echo -e '\033[70G[ \033[1;3'${1:-1mFailed}'\033[0;39m ]'
}


quit() {
	[ -d /mnt$4/etc ] || return
	grep -q serial /proc/ioports && ! grep -q ttyS /mnt$4/etc/inittab &&
	echo "ttyS0::respawn:/sbin/getty 115200,38400,9600,4800,2400 ttyS0" \
		>> /mnt$4/etc/inittab
	[ -n "$4" ] || grep -q 'tmpfs /mnt tmpfs' /proc/mounts || 
		busybox mount /mnt -o remount,ro
	busybox mount --move /run /mnt/${1:-run}
	cat > /run/init <<EOT
$2
x=/sbin/switch_root
[ -x \$x ] && exec \$x mnt $3 /sbin/init
EOT
	fail 2mDone
	exit
}


arg() {
	grep -q $1 /proc/cmdline
}


got() {
	arg $1= && root="$(sed "s/.*$1=\\([^ ]*\\).*/\\1/" </proc/cmdline)"
}


msg() {
	echo "Switching / to $1..."
}


use() {
	got $1 && msg "$1 $root"
}


bbmnt() {
	r=$(busybox blkid 2> /dev/null | grep "$root[:\"]" | sed 's|:.*||;q')
	r=${r:-$root}
	if [ ! -b $r ]; then
		r=${r#/dev/}
		r=/dev/${r%%/*}
	fi
	d=${root#*$r}
	busybox mount $r $1
}


mnt() {
	bbmnt $1 && return
	w=$(cat /sys/module/usb_storage/parameters/delay_use)
	w=$((1+${w:-2}))
	echo "Sleep $w seconds..."
	sleep $w
	bbmnt $1
}


mod() {
	for i in $@; do
		echo "Loading module: $i"
		modprobe $i 2>/dev/null ||
		for j in $(find /lib/modules|sed "/\/$i.ko/!d"); do
			busybox insmod $j && break
		done
	done
}


try() {
	if [ ! -d /mnt/etc ] && got cryptoroot; then
		mod dm-mod dm-crypt aes-256
		d=${root#/dev/}
		l=crypto-$d
		if cryptsetup isLuks $root 2>/dev/null; then
			cryptsetup luksOpen $root $l
		else
			read -st 60 -p "Pass phrase : " p
			k=$(echo $p|hashalot -x -n 32 sha512)
			echo 0 $(cat $(find /sys/block|grep /$d/size))\
			crypt aes-plain $k 0 $root 0|dmsetup create $l
		fi
		busybox mount /dev/mapper/$l /mnt
	fi
	got subroot && return
	got loopfs && return
	if [ -d /mnt/etc ]; then
		for i in $@; do
			cp -a $i /mnt$(dirname $i)
		done
		quit
	fi
	fail
}


lvm() {
	use lvmroot || return
	mod dm-mod
	vgscan --ignorelockingfailure
	vgchange -ay --ignorelockingfailure
	busybox mount /dev/mapper/$root /mnt
	try /dev/mapper $1
}


ldraid() {
	while read l; do
		case "$l" in
			*raid10*)	mod raid10;;
			*raid0*)	mod raid0;;
			*raid1*)	mod raid1;;
			*raid*)		mod raid456;;
			*mirror*)	mod dm-mirror;;
		esac
	done
}




if [ "$1" != 'log' ]; then
	busybox mount -t proc proc /proc
	busybox mount -t sysfs sys /sys
	busybox mount -t tmpfs tmpfs /run
	x=/sbin/init; echo "[ -x $x ] && exec $x" >/run/init
	$0 log 2>&1 | tee /run/boot.log
	busybox umount /sys
	busybox umount /proc
	. /run/init
	sh
fi

for i in /sys/block/*/dev /sys/block/*/*/dev ; do
	[ -s "$i" ] || continue
	n=${i%/dev}
	n=/dev/${n##*/}
	[ -e $n ] && continue
	echo "Create $n "
	mknod $n b $(sed 's/:/ /' < $i)
done

got modprobe && mod ${root//,/ }

[ -d /proc/sys/dev/cdrom ] &&
	ln -s $(sed '/name/!d;s/.*:[^a-z]*//' /proc/sys/dev/cdrom/info) /dev/cdrom

if use dmraid; then
	dmraid -s | sed '/^type/!ds/.*: *//' | ldraid
	[ ${root:0:4} = /dev ] ||
		root=/dev/mapper/$(dmraid -s|sed '/^name/!ds/.*: *//')p${root#p}
	dmraid -ay
fi
use raiddev && raiddev="DEVICE ${root//,/ }"
use raidmail && raidmail="MAILADDR $root"
if use softraid; then
	for i in 1 2 3 4 5 6 7 8 9; do
		mdadm -E -s -c partitions > /etc/mdadm.conf
		grep -qs " $root " /etc/mdadm.conf && break
		sleep $i
	done
	[ "$raiddev" ] && echo "$raiddev" >> /etc/mdadm.conf
	[ "$raidmail" ] && echo "$raidmail" >> /etc/mdadm.conf
	grep level=raid /etc/mdadm.conf | ldraid
	for i in 1 2 3 4 5 6 7 8 9; do
		sleep $i
		mdadm -A -s
		grep -qs "^$(basename $root) : act" /proc/mdstat && break
	done
	grep -qs "^$(basename $root) : act" /proc/mdstat ||
		root=$(awk '/^md/ { print "/dev/" $1; exit }' < /proc/mdstat)
	lvm /etc/mdadm.conf
fi
lvm

if got mount; then
	dev=$root
	x=$(busybox blkid|grep $dev|sed 's/:.*//;q')
	root=${x:-$dev}
	[ "$dev" = "$root" ] || dev="$root ($dev)"
	echo "Mount $dev..."
	mnt /mnt
	arg posixovl && echo "And posixovl..." &&
	mount.posixovl -F /mnt -- -oallow_other -odefault_permissions -osuid
fi

got loopfs && echo "Into file $root..." &&
	losetup /dev/loop0 /mnt/$root && busybox mount /dev/loop0 /mnt
got bindfs && echo "Bind ${root/,/ to }..." &&
	busybox mount --bind /mnt/${root%,*} /mnt/${root/,//}
arg cryptoroot= && try
if use subroot; then
	cp $(LD_TRACE_LOADED_OBJECTS=1 /lib/ld*.so /usr/sbin/chroot | sed\
		's|.*=> \(/lib/l[^ ]*\).*|\1|;/^\//!d') /usr/sbin/chroot /run
	r=$root/run
	quit $r "export LD_LIBRARY_PATH=$r:/lib"\
		"$root$(ls /run/ld-*so) $r/chroot $root" "/$root"
fi
quit
msg tmpfs
root=100
got tmpram
r=$root
inodes=0
got rootfsinodes && inodes=$root
root=90%
got rootfssize
[ $(busybox free|busybox awk '/Mem:/{print int(($4*100)/$3)}') -ge $r ] &&
	busybox mount -t tmpfs -o size=$root,nr_inodes=$inodes tmpfs /mnt &&
	for i in $(ls -ar /); do
		case "$i" in
			.*|cdrom)	;;
			mnt|proc|sys)	mkdir /mnt/$i;;
			usr|var|rootfs*) mv /$i /mnt;;
			*)	cp -a /$i /mnt 2>/dev/null && continue
				fail
				busybox umount /mnt
				exit
		esac
	done || fail 3mSkipped
quit
mod squashfs 2>/dev/null || exit
msg aufs
br=/mnt/.rw
mkdir $br /mnt/.wd
got rwdev && mnt $br && br=$br$d
o=
p=
c=/mnt/.cdrom
if [ -z "$(ls /mnt/rootfs* 2>/dev/null)" ]; then
	root=/dev/cdrom/fs
	got rodev
	mkdir -p $c /mnt$c /mnt/.rw$c
	mnt $c
	o="-o 124"
	p=/.cdrom/boot
	c=$c$d
fi
l=0
r=
got isofs && r=:$c || for i in /mnt$p/rootfs?*.gz; do
	fs=${i#*root}
	r=$r:/mnt/.$fs
	mkdir -p /mnt/.rw/mnt/.$fs /mnt/.$fs
	losetup $o /dev/loop$l $i
	busybox mount -o ro -t squashfs /dev/loop$((l++)) /mnt/.$fs
done
while read type opt; do
	mod $type && busybox mount -t $type -o $opt none /mnt && break
done <<EOT
aufs		br=$br$r
overlayfs	workdir=/mnt/.wd${r/:/,lowerdir=},upperdir=$br
EOT
quit
