On Fri, Jan 19, 2024, 19:12 Morten Bo Johansen <mortenbo@xxxxxxxxxxx> wrote:
On 2024-01-19 Mantas Mikulėnas wrote:
> In general I've learned to not quite trust what the firmware shows... we've
> had a batch of Skylake-or-so desktops that *did* have a CPU-integrated fTPM
> but it wasn't even mentioned until we did a BIOS update, even though CPU
> spec said it should be present.
>
> However, your CPU is from Haswell era and according to the spec sheet it
> definitely seems to lack Intel's PTT "built-in TPM 2.0" feature (it has the
> older IPT but that's a different thing, not a TPM equivalent), so that
> seems correct. If I understand correctly, the only option for that CPU
> would be a discrete TPM chip, and if the manufacturer had bothered to
> include one, it ought to be showing up in the BIOS settings.
>
> On the other hand, you said you have a /dev/tpm0... I'm somewhat curious
> about whether there are any mentions 'tpm' or 'tis' or something like that
> in your `dmesg`?
~/ % dmesg | grep -i tpm
[ 0.275738] tpm_tis 00:05: 1.2 TPM (device-id 0x0, rev-id 78)
Well, that also looks like a TPM1.2 is present; it matches the absence of /dev/tpmrm0 (which is a 2.0 thing).
(It's not very useful in general; I've used it to store my SSH key in the past, but it's slow and only does RSA-2048, and the software is completely different from what's used for newer variants. You can use it through TrouSerS + OpenCryptoki.)
I wonder what makes systemd think it's a 2.0.
