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mudbugos/initramfs/resources/initramfs-init

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#!/bin/busybox sh
# shellcheck shell=sh
# shellcheck disable=SC2039
#
# Really, this should be ash, not sh, but shellcheck doesn't support ash, see
# https://github.com/koalaman/shellcheck/issues/853
# SC2039 is there because of that (local/== unsupported in sh, work in ash)
# This is the init script built into the PrawnOS initramfs
# This file is part of PrawnOS (https://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
echo "Something went wrong. Dropping to a 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}"
}
# a clever portable shell script to detect occurances of a substring in a string
# occur <string> <substring> (optional count)
# if optional count is not provided:
# returns 1 if substring is not in string
# returns 0 otherwise
# if optional count is provided:
# returns 1 if substring occurs in string < optional count
# returns 0 otherwise
occur() {
while case "$1" in (*"$2"*) set -- \
"${1#*"$2"}" "$2" "${3:-0}" "$((${4:-0}+1))";;
(*) return "$((${4:-0}<${3:-1}))";;esac
do : "${_occur:+$((_occur=$4))}";done
}
# mount the bare necesities
mount -n -t proc proc /proc
mount -n -t sysfs sysfs /sys
mount -n -t devtmpfs devtmpfs /dev
# get the root device, so we can find the boot partiton
UNPARSED=$(cmdline root)
echo Unparsed cmdline rootdev: ${UNPARSED} > /dev/tty1
ROOT_PARTUUID=$(rootpartuuid $UNPARSED)
echo ROOT_PARTUUID: ${ROOT_PARTUUID} > /dev/tty1
BLKID=$(/sbin/blkid | grep $ROOT_PARTUUID )
echo BLKID: ${BLKID} > /dev/tty1
if [ -z "$BLKID" ]
then
echo BLKID wasnt found yet, give the kernel a moment... > /dev/tty1
sleep 1
BLKID=$(/sbin/blkid | grep $ROOT_PARTUUID )
if [ -z "$BLKID" ]
then
echo BLKID still not found, give the kernel one more moment... > /dev/tty1
sleep 1
BLKID=$(/sbin/blkid | grep $ROOT_PARTUUID )
if [ -z "$BLKID" ]
then
echo FAILED TO FIND BLKID AFTER 2 SECONDS, PLEASE OPEN AN ISSUE WITH A SCREENSHOT OF THIS ERROR > /dev/tty1
rescue_shell
fi
fi
fi
echo BLKID: ${BLKID} > /dev/tty1
# If it's an mmcblk device, the kernel partiton will be p1. If it is a usb device, the partiton will just be 1.
# Just want everything before the 1
ROOT_DEV="${BLKID%1:*}"
echo ROOT_DEV: ${ROOT_DEV} > /dev/tty1
# label any partition on the system with RESCUESHELL to enter the initramfs rescue shell before mount and root_switch.
# you can do this with "cgpt add -i 1 -l RESCUESHELL /dev/sda" for example to label the first partiton of a usb drive.
if blkid | grep -q RESCUESHELL; then
rescue_shell debug
fi
if blkid ${ROOT_DEV}2 | grep -q crypto_LUKS; then
# decrypt and mount the root filesystem, disable kernel log messages to avoid clashing with the prompt
dmesg -n 2
echo "Opening encrypted root partition, this will take 30s..."
cryptsetup --tries 5 luksOpen ${ROOT_DEV}2 luksroot || rescue_shell
dmesg -n 7
mount /dev/mapper/luksroot /newroot
else
# mount the unencrypted root filesystem
[ -d "/newroot" ] || mkdir -p /newroot
mount ${ROOT_DEV}2 /newroot
fi
umount /sys
umount /proc
#switch to the new rootfs
exec switch_root /newroot /sbin/init