create-root-on-usb.sh

#!/bin/sh
if [ -z "$1" ]; then
    echo "Input device (ex. /dev/sda1)"
    exit
fi
TARGET="${1}"

MOUNT_POINT="/mnt/$(basename $TARGET)"
echo "Make sure the partition on $TARGET is safe for deletion"
read -p "Do you wish to continue [yN]? " answer;
if echo "$answer" | grep -iq "^y"; then
    echo "Updating opkg package list"
    opkg -V0 update
    echo "Creating ext4 partition on $TARGET"
    opkg -V0 install e2fsprogs -d ram
    export PATH=$PATH:/tmp/bin:/tmp/sbin:/tmp/usr/bin:/tmp/usr/sbin
    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/tmp/lib:/tmp/usr/lib
    mkfs.ext4 $TARGET
    
    echo "Mounting $TARGET to $MOUNT_POINT"
    mkdir -p $MOUNT_POINT
    mount $TARGET $MOUNT_POINT
    mkdir -p /tmp/cproot
    mount --bind / /tmp/cproot
    tar -C /tmp/cproot -cvf - . | tar -C $MOUNT_POINT -xf -
    umount /tmp/cproot
    umount $MOUNT_POINT
    
    echo "Setting up fstab"
    # block detect > /etc/config/fstab
    /etc/init.d/fstab enable
    uci batch << EOF
set fstab.@mount[0].uuid=$(block detect | grep uuid | awk '{ print $3 }')
set fstab.@mount[0].target='/'
set fstab.@mount[0].fstype='ext4'
set fstab.@mount[0].option='rw,sync'
set fstab.@mount[0].enabled='1'
set fstab.@mount[0].enabled_fsck='0'
commit fstab
EOF
    read -p "Press enter to restart the router"
fi