Re: 5.3 boot regression caused by 5.3 TPM changes

[Ard Biesheuvel]

Hi Hans,

On Sun, 4 Aug 2019 at 13:00, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Hi All,
>
> While testing 5.3-rc2 on an Irbis TW90 Intel Cherry Trail based
> tablet I noticed that it does not boot on this device.
>
> A git bisect points to commit 166a2809d65b ("tpm: Don't duplicate
> events from the final event log in the TCG2 log")
>
> And I can confirm that reverting just that single commit makes
> the TW90 boot again.
>
> This machine uses AptIO firmware with base component versions
> of: UEFI 2.4 PI 1.3. I've tried to reproduce the problem on
> a Teclast X80 Pro which is also CHT based and also uses AptIO
> firmware with the same base components. But it does not reproduce
> there. Neither does the problem reproduce on a CHT tablet using
> InsideH20 based firmware.
>
> Note that these devices have a software/firmware TPM-2.0
> implementation, they do not have an actual TPM chip.
>
> Comparing TPM firmware setting between the 2 AptIO based
> tablets the settings are identical, but the troublesome
> TW90 does have some more setting then the X80, it has
> the following settings which are not shown on the X80:
>
> Active PCR banks:           SHA-1         (read only)
> Available PCR banks:        SHA-1,SHA256  (read only)
> TPM2.0 UEFI SPEC version:   TCG_2         (other possible setting: TCG_1_2
> Physical Presence SPEC ver: 1.2           (other possible setting: 1.3)
>
> I have the feeling that at least the first 2 indicate that
> the previous win10 installation has actually used the
> TPM, where as on the X80 the TPM is uninitialized.
> Note this is just a hunch I could be completely wrong.
>
> I would be happy to run any commands to try and debug this
> or to build a kernel with some patches to gather more info.
>
> Note any kernel patches to printk some debug stuff need
> to be based on 5.3 with 166a2809d65b reverted, without that
> reverted the device will not boot, and thus I cannot collect
> logs without it reverted.
>

Are you booting a 64-bit kernel on 32-bit firmware?