cros_post_src_install_trousers_flatcar_modifications() {
    # override the systemd unit file and enable it
    systemd_newunit - tcsd.service <<'EOF'
[Unit]
Description=TCG Core Services Daemon
ConditionPathExists=/dev/tpm0
ConditionSecurity=!tpm2

[Service]
User=tss
ExecCondition=/bin/bash -c "/usr/bin/test $(cat /sys/class/tpm/*/tpm_version_major | grep -m 1 1 || echo 0) -eq 1"
ExecStart=/usr/sbin/tcsd -f

[Install]
WantedBy=multi-user.target
EOF
    systemd_enable_service multi-user.target tcsd.service

    # handle system.data file - put into /usr and install a tmpfiles
    # conf copying it into /var/lib/tpm
    (
        insinto /usr/share/trousers/
        insopts -o tss -g tss
        newins - system.data <<<"/"
    )
    (
        insopts -m 0644
        insinto /usr/lib/tmpfiles.d
        newins - trousers.conf <<'EOF'
C /var/lib/tpm/system.data 0600 tss tss - /usr/share/trousers/system.data
EOF
    )

    # symlink for backward compatibility, can't use "dosym -r",
    # because ebuild has EAPI 7, while "dosym -r" is supported only
    # since EAPI 8.
    #
    # dosym -r /usr/share/flatcar/etc/tcsd.conf /usr/share/trousers/tcsd.conf
    ln -sTr "${ED}/usr/share/flatcar/etc/tcsd.conf" "${ED}/usr/share/trousers/tcsd.conf" || die
    insinto /usr/share/flatcar/etc
    newins - tcsd.conf
}
