diskimage-builder/diskimage_builder/elements/tpm-emulator/install.d/tpm-emulator-source-install/tpm_server.service

[Unit]
Description=TPM server

[Service]
ExecStart=/usr/local/bin/tpm_server -rm
Restart=on-failure
RestartSec=30s

[Install]
WantedBy=multi-user.target