I don't normally keep up with Purism but I have to say that this is interesting: https://puri.sm/posts/introducing-the-librem-key/
Along with https://puri.sm/posts/demonstrating-tamper-detection-with-heads/
It would be neat if that were available in libreboot; http://osresearch.net/
Although I think not all librebootable devices have a TPM. But perhaps there are other ways to pull off the idea without one.
It's not really that interesting. With a decent open diceware passphrase and full disk encryption (including /boot/) you should be pretty much OK.
And anyway it's not a good idea to promote Purism as a company, even if they do one or two nice things on occasion.
it's a nice concept, but please link to one that isn't sold by purism :)
It's a terrible concept that would just add obfuscation. TPM doesn't provide root of trust but relies on it. Possibility of replaying PCRs values on a target nullifies effects of TPM use in boot chain.