tpm_createek creates and Endorsement Key Pair on the TPM (via the TPM_CreateEndorsementKeyPair API). This should rarely be required as the Endorsement Key is normally installed as part of manufacturing. However, you might need to run this command once if commands such as tpm_getpubek are returning error code 35 from the TPM layer.
tpm_version(1) , tpm_getpubek(8) , tcsd(8)