I am not using a resource manager and I can't talk to the TPM!

If you are receiving an error message like the following when running commands:

$ tpm2_pcrlist
ERROR: Tss2_Sys_GetCapability(0x100) - tpm:error(2.0): TPM not initialized by TPM2_Startup or already initialized
ERROR: Unable to run tpm2_pcrlist

or

$ tpm2_listpcrs --socket-port=2321
ERROR: GetCapability: Get PCR allocation status Error. TPM Error:0x100......

Make sure you have initialized the TPM by running tpm2_startup:

On Ubuntu 18.10 and earlier:

$ tpm2_startup --socket-port=2321 --clear

On Ubuntu 19.04 and newer:

$ TPM2TOOLS_TCTI=mssim TPM2TOOLS_TCTI_SOCKET_ADDRESS=127.0.0.1 TPM2TOOLS_TCTI_SOCKET_PORT=2321 tpm2_startup -c