1if have_tpm 2 system_ss.add(files('tpm_backend.c')) 3 system_ss.add(files('tpm_util.c')) 4 system_ss.add(when: 'CONFIG_TPM_PASSTHROUGH', if_true: files('tpm_passthrough.c')) 5 system_ss.add(when: 'CONFIG_TPM_EMULATOR', if_true: files('tpm_emulator.c')) 6endif 7