Help recalculating TPMv2 PCR8 value without actually booting

[David Elie-Dit-Cosaque]

Hi,
I am trying to recalculate the value of TPM PCR 8 the way grub does it
during boot but I could not figure it out yet.
Grub seems to calculate a digest for every line of the grub.conf that is
rendered after executing every control structure such as if statement for
loops, etc...
Is there a way to generate such a rendered command list without actually
booting? The tpm2_eventlog lists all these commands as events measured for
PCR 8 after the fact.

Was there any previous discussion to add a grub command to calculate the
value of PCR8 (and others) without actually rebooting?

Thanks!
David.