#!/bin/bash
# Snapshot kernel + modules + bes2600 firmware from ohm into ~/backup/.
#
# Per feedback_backup_before_replace.md: always backup before replacing
# kernel/modules/configs, with versioned labels.

set -e

TS=$(date +%Y%m%d-%H%M%S)
KVER=$(uname -r)
DEST=/home/mfritsche/backup
mkdir -p ${DEST}

OUT=${DEST}/ohm-kernel-${KVER}-${TS}.tar.zst

echo "=== Sizes ==="
sudo du -sh /boot /lib/modules/${KVER} /lib/firmware/bes2600

echo "=== Tar ==="
sudo tar --use-compress-program='zstd -3' \
    -cf "${OUT}" \
    -C / boot lib/modules/${KVER} lib/firmware/bes2600
sudo chown $(id -un):$(id -gn) "${OUT}"

echo "=== Result ==="
ls -lah "${OUT}"
zstd -t "${OUT}" 2>&1 | tail -1