99-balena-bootloader

#!/bin/sh

#
# Script which configures bootenv to use an updated root partition
#

set -o errexit

. /usr/sbin/balena-config-vars
. /usr/libexec/os-helpers-logging

DURING_UPDATE=${DURING_UPDATE:-0}

if [ "${DURING_UPDATE}" = "1" ]; then
	SYSROOT="/mnt/sysroot/inactive"
else
	SYSROOT="/mnt/sysroot/active"
fi

NEW_ROOT_PART=$(findmnt --noheadings --canonicalize --output SOURCE ${SYSROOT} -t ext4)
NEW_ROOT_LABEL=$(lsblk -nlo label "${NEW_ROOT_PART}")
NEW_ROOT=$(echo "${NEW_ROOT_LABEL}" | sed -e "s,^\(resin\|balena\)-root\([AB]\)$,\2,")

info "Switching root partition to ${NEW_ROOT}"

BOOTENV_FILE="${BALENA_NONENC_BOOT_MOUNTPOINT}/bootenv"

# When migrating to balena bootloader make sure no alternative is present
rm -f "${BALENA_NONENC_BOOT_MOUNTPOINT}/resinOS_uEnv.txt"
rm -f "${BALENA_NONENC_BOOT_MOUNTPOINT}/grubenv"

grub-editenv "${BOOTENV_FILE}" set "resin_root_part=${NEW_ROOT}"
grub-editenv "${BOOTENV_FILE}" set "upgrade_available=${DURING_UPDATE}"

info "Will use root ${NEW_ROOT} during next boot"