diskimage-builder/diskimage_builder/elements/block-device-mbr/environment.d/15-block-device.bash

#
# Arch gate
#

if [[ "arm64 aarch64" =~ $ARCH ]]; then
    echo "block-device-mbr is not supported on AARCH64; use block-device-efi"
    exit 1
fi

export DIB_BLOCK_DEVICE=mbr