Re: [PATCH v7 0/3] Add support for TPM devices over I2C bus

[Stefan Berger <stefanb@linux.ibm.com>]

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