Re: tpm_tis TPM2.0 not detected on cold boot

From: Ken Goldman
Date: Mon Dec 31 2018 - 13:10:29 EST

On 12/30/2018 8:22 AM, Michael NiewÃhner wrote:
difference is that on a cold boot, the TPM takes longer to initialize.
Well, as I said. Waiting for 10, 20 or even 60 seconds in the boot manager does
not solve the problem. So the problem is NOT that the TPM takes longer to
initialize. Even adding a delay of 20 seconds before TPM init does not solve
that while that should be more than enough time.

This may be TPM hardware dependent. As I understand it ...

A TPM is permitted to run it's self tests in the background after an
Init (cold boot) , but it's not required to do so.

A TPM that does not - that waits until one of the self test commands is issued - will appear to take longer to initialize.

In fact, it's not taking longer. It's just waiting for some software
to issue a self test command, and will wait forever.