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

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

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.

     Stefan