Both RT Journey Measurements Are Equal Following a FW Update

chipsalliance / caliptra-sw

Caliptra software (ROM, FMC, runtime firmware), and libraries/tools needed to build and test

Apache License 2.0

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Both RT Journey Measurements Are Equal Following a FW Update #1673

Open nquarton opened 3 weeks ago

nquarton commented 3 weeks ago

Both RTJM values are the same values following a FW update. This seems unexpected given the way we understand they are calculated and the fact they differ in the cold boot case.

While we understand one of these values is not useful as it is a journey of a journey measurement, the concern is that something may be broken because they are equal.

jhand2 commented 2 weeks ago

This is intentional, but I'm open to representing it a different way if we prefer. During hitless update, we populate the RTJM with the latest value of the RT journey PCR: https://github.com/chipsalliance/caliptra-sw/blob/main/runtime/src/drivers.rs. See update_dpe_rt_journey implementation.