Edit files inside prebuilt system.img.raw

# Add a file in side pre-dumped system.img.raw
cd $L4T/bootloader

## Check size
sudo fdisk -l system.img.raw
# Disk system.img.raw: 58 GiB, 62277025792 bytes, 121634816 sectors

## Mount the system.img.raw as loop device
sudo losetup -fP system.img.raw
LOOP=$(sudo losetup -a | grep -i system.img.raw | awk -F ":" ' { print $1 }')
echo $LOOP

MNT=/mnt/loop_mnt
sudo mkdir -p $MNT
sudo mount $LOOP $MNT

## Add a file in the loop device



## Unmount the loop device 
sudo umount $MNT
sudo losetup -d $LOOP
sudo rm $LOOP