wicshell.sh

#!/bin/bash
#
# Authors:
#  Roberto A. Foglietta <roberto.foglietta@gmail.com>
#
# SPDX-License-Identifier: MIT
#

function getloopdev() {
	if [ -b "$fimg" ]; then
		if [ -b ${fimg}2 ]; then
			echo ${fimg}2 
		elif [ -b ${fimg}p2 ]; then
			echo ${fimg}p2
		else
			echo ${fimg}
		fi	
		return $?
	fi
	local a
	a=$(losetup -j $fimg | cut -d: -f1)
	a=$(ls -1v "$a" 2>/dev/null | tail -n1)
	d=${a:+${a}p2}
	test -b "$d" && echo $d && return 0
	d=${a:+${a}p1}
	test -b "$d" && echo $d && return 0
	d=$a
	test -b "$d" && echo $d && return 0
}

function umountall() {
        set +e
        umount -R ${1:-$rootdir}
        if getloopdev >/dev/null; then 
		losetup -d ${bdev/p[12]/}
		getloopdev | sed -e "s,\(.*\),ERROR: loop device \\1 is still busy!,"
	fi
	echo
}

function jumpinto() {
	set -e
	test -b $bdev
	mkdir -p $rootdir
	mount $bdev $rootdir
	mkdir -p $rootdir/work
	mount -o bind build/tmp/work $rootdir/work
	mkdir -p $rootdir/isar-apt
	mount -o bind build/tmp/deploy/isar-apt $rootdir/isar-apt
	mount -t sysfs sys $rootdir/sys
	mount -t proc proc $rootdir/proc
	mount -t devtmpfs udev $rootdir/dev
	mount -t devpts devpts $rootdir/dev/pts
	mount -t cgroup2 cgroup2 $rootdir/sys/fs/cgroup
	echo "chroot into $(basename $fimg)..."
	echo

	export debian_chroot=chroot
	hostname=$(cat $rootdir/etc/hostname)
	hostname=${hostname:-unknown}
	sed -i "s,\(127.0.0.1.*localhost$\),\\1 $hostname $HOSTNAME," $rootdir/etc/hosts
	export HOSTNAME=$hostname
	if true; then echo '#!/usr/bin/env
hostname -F /etc/hostname
export HOSTNAME=$(hostname -s); export HOME=/root
source /etc/profile; source /etc/locale; export LC_ALL
'$(env | grep _proxy= | sed -e "s,\(.*\),export \\1;,")'
alias exp-last-part=/usr/share/expand-on-first-boot/expand-last-partition.sh
echo $debian_chroot hostname: $(hostname -s), current user: $(whoami)
echo; cd'
	fi > $rootdir/root/.chrootrc
	chroot $rootdir /bin/bash --rcfile /root/.chrootrc -ic bash

	echo "chroot exiting..."
}

if [ "$(whoami)" != "root" ]; then
    echo
    echo "WARNING: this script should run as root, sudo!"
    sudo -E $0 "$@"
    exit $?
fi

if [ -e "$1" ]; then
	fimg=$(readlink -e $1)
fi

cd $(dirname $0)

if [ ! -n "$1" -a  ! -e "$fimg" ]; then
    echo "Searching the image..."
	fimg=$(ls -1 build/tmp/deploy/images/*/*.wic)
	n=( $fimg )
	if [ ${#n[@]} -gt 1 ]; then
		echo
		echo "WARNING: more than one image found, choose one:"
		echo
		echo "$fimg"
		echo
		exit 1
	fi
fi

if [ ! -e "$fimg" ]; then
	echo
	echo "ERROR: no any image or block device ${1:+'$1' }found, abort!"
	echo
	exit 1
fi

rootdir=build/root
bdev="$(getloopdev)"
trap "umountall $(readlink -f $rootdir)" EXIT
set -e
echo
if [ -b "$fimg" ]; then
	jumpinto $fimg
elif [ -b "$bdev" ]; then
	echo "WARNIING: using a previous loop device $bdev"
	echo
	jumpinto $bdev
else
	losetup -Pf $fimg
	bdev=$(getloopdev)
	jumpinto $bdev
fi