Re: tpm_tis TPM2.0 not detected on cold boot

From: Mimi Zohar
Date: Sat Dec 22 2018 - 17:55:27 EST

On Sat, 2018-12-22 at 14:47 +0100, Michael NiewÃhner wrote:

> When I remove the timeout and boot directly to the linux kernel, I get that
> "2314 TPM-self test error" since it has not finished, yet. The TPM is detected
> by IMA and works fine then.
> Some more tests showed that any delay before booting the kernel causes the TPM
> to not get detected. I tested, 10, 15, 20, 30, 60... seconds. Only in some very
> rare cases the TPM got detected.
> I wanted to know if the TPM is in an well initialized state at the time of that
> error. Since I was not able to get some test/debug kernel patches working I
> decided to try kexec. It turned out that the TPM is indeed correctly working and
> will be detected just fine by linux after kexec!

No surprise here. Âkexec would be the equivalent of a soft reboot.

> Is there anyone having an idea what could be wrong here? I am willing to debug
> this but I have really no idea where to start :-(

A while ago, I was "playing" with a pi. ÂCommenting out
tpm2_do_selftest() seemed to resolve a similar problem, but that was
before James' patches. ÂI don't know if that would make a difference