#!/bin/busybox sh

# This is the init script built into the PrawnOS initramfs

# This file is part of PrawnOS (http://www.prawnos.com)
# Copyright (c) 2018 Hal Emmerich <hal@halemmerich.com>

# PrawnOS is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2
# as published by the Free Software Foundation.

# PrawnOS is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with PrawnOS.  If not, see <https://www.gnu.org/licenses/>.

echo In PrawnOS Init

#add this to start shell at desired point
rescue_shell() {
    [ "{$1}" != "debug" ] && echo "Something went wrong. Dropping to a shell." > /dev/tty1
    [ "{$1}" == "debug" ] && echo "Debug flag detected, entering debug shell" > /dev/tty1
    exec setsid /bin/sh -c 'exec /bin/sh </dev/tty1 >/dev/tty1 2>&1'
}

#used to parse the kernel cmdline
cmdline() {
    local value
    value=" $(cat /proc/cmdline) "
    value="${value##* ${1}=}"
    value="${value%% *}"
    [ "${value}" != "" ] && echo "${value}"
}

#used to get the uuid of the root partiton since findfs isn't in debian busybox-static
rootpartuuid() {
    local value
    value=$1
    value="${value%/*}"
    value="${value#*=}"
    [ "${value}" != "" ] && echo "${value}"
}

# mount the bare necesities 
mount -n -t proc     proc      /proc
mount -n -t sysfs    sysfs     /sys
mount -n -t devtmpfs devtmpfs  /dev

# get the root device, so we can find the boot partiton
UNPARSED=$(cmdline root)
ROOT_PARTUUID=$(rootpartuuid $UNPARSED)
echo ${ROOT_PARTUUID} > /dev/tty1
BLKID=$(/bin/blkid | grep $ROOT_PARTUUID )
echo ${BLKID} > /dev/tty1
#If its an mmcblk device, the kernel partiton will p1. If it is a usb device, the partiton will just be 1
#Just want everything before the 1
ROOT_DEV="${BLKID%1:*}"

echo ${ROOT_DEV} > /dev/tty1

# we can use this to change what cmdline options get passed into
# the next boot stage
CMDLINE='cat /proc/cmdline'

[ -d "/boot" ] || mkdir -p /boot
mount ${ROOT_DEV}2 /boot

#Debugging can be facilitated by creating /boot/debug
[ -f "/boot/debug" ] && rescue_shell debug

if [ -f "/boot/root_encryption" ]
then
    #decrypt and mount the root filesystem
    echo "Opening encrypted root partition, this will take 30s..."
    cryptsetup --tries 5 luksOpen ${ROOT_DEV}3 luksroot || rescue_shell debug
    mount /dev/mapper/luksroot /newroot
else
    # mount the unencrypted root filesystem
    [ -d "/newroot" ] || mkdir -p /newroot
    mount ${ROOT_DEV}3 /newroot
fi

umount /sys
umount /proc



#swith to the new rootfs
exec switch_root /newroot /sbin/init ${CMDLINE}