Re: [PATCH v3 4/5] efi: call get_event_log before ExitBootServices

From: Jarkko Sakkinen
Date: Thu Oct 26 2017 - 14:59:05 EST


On Tue, Oct 17, 2017 at 10:00:15AM +0200, Thiebaud Weksteen wrote:
> This patch was mainly developed and tested on Kabylake with PTT as well.
>
> It could be a few things. Are you booting with the EFI stub? Is the
> TPM enabled within the BIOS? Does tpm_tis get loaded? Does it produce
> any log?

Nope, and it should not get loaded anyway as I'm using PTT. With PTT you
use tpm_crb. TPM is working just fine.

> If the logs are recovered (but not parsed), you should already see an
> entry in the logs like:
>
> efi: SMBIOS=0x7fed6000 ACPI=0x7ff00000 TPMEventLog=0x.....
>
> Can you see the TPMEventLog part?

I can check this when I'm back in Finland. Still in Prague. Tried to
test this with my work laptop (XPS13 with dTPM) now but the USB stick I
have with seems to be broken :-(

This is anyway almost guaranteed to go to 4.16 and I don't want to push
this to 4.15 so there is no rush right now (already sent my PR).

> The issue with extra logging is that the log recovery happens within
> the EFI stub phase where limited logging is available (which I think
> has been limited to error and fatal message only).
> For now, it cannot be a version mismatch as the stub will only request
> the version 1.2 format.

Right, I see.

/Jarkko