mnt_kern.sh

mnt_kern.sh

#!/bin/sh

set -eu

if [[ "$#" -ne 1 ]]; then
	echo "Usage: mnt_kern <directory>"
	exit 1
fi

if [[ ! -r "squash/${1}.sqfs" ]]; then
	echo "No squashfs file found in squash folder"
	exit 1
fi

KERND=$1
LOWER=/var/tmp/overlayfs/lower/${KERND}
UPPER=/usr/src/overlay/${KERND}
WORKD=/var/tmp/overlayfs/workdir/${KERND}
MERGD=/usr/src/${KERND}

[[ -d ${LOWER} ]] || mkdir -p ${LOWER}
[[ -d ${UPPER} ]] || mkdir -p ${UPPER}
[[ -d ${WORKD} ]] || mkdir -p ${WORKD}
[[ -d ${MERGD} ]] || mkdir -p ${MERGD}

mount -r -o nodev,noexec,noatime squash/${KERND}.sqfs ${LOWER}
mount -t overlay -o lowerdir=${LOWER},upperdir=${UPPER},workdir=${WORKD} overlay ${MERGD}

This needs making:

• portable (no bashisms...!)
• safe when squashfs is unavailable
• safe when overlayfs in unavailable