testsize.sh

IMG_FILE="/home/jelle/git/wifibroadcast-image-builder/data/2018-10-09-raspbian-stretch-lite_2018-10-24.img"

PARTED_OUT=$(parted -s "${IMG_FILE}" unit b print)
BOOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^ 1'| xargs echo -n \
| cut -d" " -f 2 | tr -d B)
BOOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^ 1'| xargs echo -n \
| cut -d" " -f 4 | tr -d B)

ROOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^ 2'| xargs echo -n \
| cut -d" " -f 2 | tr -d B)
ROOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^ 2'| xargs echo -n \
| cut -d" " -f 4 | tr -d B)

BOOT_DEV=$(losetup --show -f -o "${BOOT_OFFSET}" --sizelimit "${BOOT_LENGTH}" "${IMG_FILE}")
ROOT_DEV=$(losetup --show -f -o "${ROOT_OFFSET}" --sizelimit "${ROOT_LENGTH}" "${IMG_FILE}")
echo "/boot: offset $BOOT_OFFSET, length $BOOT_LENGTH"
echo "/:     offset $ROOT_OFFSET, length $ROOT_LENGTH"