Aw: Re: [tpmdd-devel] [PATCH v9 8/8] tpm: TPM 2.0 FIFO Interface

[Peter Huewe]

> 
> > Am Donnerstag, 4. Dezember 2014, 06:55:18 schrieb Jarkko Sakkinen:
> > > From: Will Arthur <will.c.arthur@xxxxxxxxx>
> > >
> > > Detect TPM 2.0 by using the extended STS (STS3) register. For TPM 2.0,
> > > instead of calling tpm_get_timeouts(), assign duration and timeout
> > > values defined in the TPM 2.0 PTP specification.
> > >
> > > Signed-off-by: Will Arthur <will.c.arthur@xxxxxxxxx>
> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> 
> > >
> > > + sts3 = ioread8(chip->vendor.iobase + TPM_STS3(1));
> > > + if ((sts3 & TPM_STS3_TPM2_FAM) == TPM_STS3_TPM2_FAM)
> > > + chip->flags = TPM_CHIP_FLAG_TPM2;
> > > +
> > >
> 
> >
> > When loading tpm_tis force=1 with my tpm1.2 chip on a machine without bios
> > integration, it fets detected as a TPM2.0 chip :/
> >
> > sudo rmmod tpm_tis
> > # modprobe tpm_tis force=1
> > modprobe: ERROR: could not insert 'tpm_tis': No such device
> > # dmesg
> > [ 263.903828] tpm_tis tpm_tis: 2.0 TPM (device-id 0xB, rev-id 16)
> > [ 263.948049] tpm_tis tpm_tis: A TPM error (10) occurred continue selftest
> > [ 263.948120] tpm_tis tpm_tis: TPM self test failed
> >
> >
> > sts3 is reported as 0xff from my TPM1.2
> >
> 
> 
> Hmm,
> my TPM2.0 chip also reports sts3 as 0xff (when loading with force=1 on a
> machine without bios integration)
> 
> [ 307.095344] sts3 ff
> [ 307.095366] tpm_tis tpm_tis: 2.0 TPM (device-id 0x1A, rev-id 16)
> [ 307.140047] tpm_tis tpm_tis: A TPM error (256) occurred continue selftest
> [ 307.140056] tpm_tis tpm_tis: TPM self test failed


You are reading "sts3" - before requesting the locality and thus it returns 0xff for a TPM20 chip as well.
--> You have to have an active locality first.


For a TPM2.0 0xFF is not a valid value (if active locality is set), since reading commandCancel and resetEstablishment bit always return 0 on reads (according to spec).

--> 0xFF should be treated as a TPM1.2 (older tpms with TIS 1.2)
--> 0x04 should be treated as TPM 2.0
--> 0x08 should be treated as TPM1.2 (newer tpms with TIS1.3 enhanced)



Thanks,
Peter
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