On 3/6/2017 7:55 AM, Chris Hawkins wrote: > Pritha, > > What I believe you are observing is that the PCRs are being reset on > boot, but are being extended as expected by the BIOS/UEFI (PCRs 0-7) and > the OS (PCRs 8-15). It's rare to find a platform that can enable and > activate a TPM but it's not configured to extend PCRs on boot. GRUB is > also TPM aware, and will also extend PCRs. Because your boot environment > rarely changes, the extended PCR values will generally be identical > after every boot. Update a BIOS revision, and you'll see these change. > Not many other things will affect a change. These unchanging values may > imply that the PCRs are never being reset, but they almost certainly > are. They are just being extended by measurement of the same, unchanging > things, on every boot.
I don't think that's the issue. Note that the poster extended PCR0, rebooted, and got the new value. If it was the BIOS/UEFI, it would go back to the old value. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ TrouSerS-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/trousers-users
