collection/docs/create-image-file.md

get/create image file

download and extract an image file or create one using dd if=/dev/zero of=<image-file> bs=<block-size> count=<count>.

set image size

set image size with truncate --size=<size> <image-file>. this is usually used to increase image size in order to increase the file system size (i.e. make more space for rootfs)

mount image

to mount an image file use

mount -o loop <path/to/image-file> <mount-point>

if the image contains multiple partitions one needs to setup a loop device first:

losetup --find --show <path/to/image-file> -P

afterwards the partitions of the image should be shown as loopXpY and can be mounted like any other device.

modify partition table with fdisk

resize partition for rootfs

resize filesystem

mount boot partition

make file 'ssh'

make user config

remove image resize from config file ~'cmdline.txt'

mount rootfs partition

do stuff