On 3/27/23 08:31, Stefan Berger wrote:


On 3/27/23 07:11, Stefan Berger wrote:



We get this message when booting from a kernel:

[    0.582699] tpm_tis_i2c 12-002e: 2.0 TPM (device-id 0x1, rev-id 1)
[    0.586361] tpm tpm0: A TPM error (256) occurred attempting the self test
[    0.586623] tpm tpm0: starting up the TPM manually

Do we understand why the error appears?

The firmware did not initialize the TPM 2.


However on a clean boot into the TPM, the u-boot tpm commands fail:

ast# tpm info
tpm@2e v2.0: VendorID 0x1014, DeviceID 0x0001, RevisionID 0x01 [closed]
ast# tpINTERRUPT>

Is this normal output? Is it an indication of some sort of IRQ?

ast# tpm init
ast# tpm info
tpm@2e v2.0: VendorID 0x1014, DeviceID 0x0001, RevisionID 0x01 [open]
ast# tpm pcr_read 0 0x81000000
Error: 256

If this is an error from the TPM 2 , then the 256 error code is the same as 
reported by Linux above:

$ tssreturncode 0x100
TPM_RC_INITIALIZE - TPM not initialized by TPM2_Startup or already initialized


I will try to reproduce this today. u-boot should have a sent TPM2_Startup as 
part of 'tpm init' command above or even before on its own.

One needs to do this here:

ast# tpm2 startup TPM2_SU_CLEAR
ast# tpm2 pcr_read 0 0x81000000
PCR #0 content (332 known updates):
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

   Stefan

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