System time

Posted Jul 18, 2025 0:35 UTC (Fri) by marcH (subscriber, #57642)
In reply to: System time by aaribaud
Parent article: Linux and Secure Boot certificate expiration

I recently lost all video outputs after trying some "unusual" BIOS settings (lesson learned...)

I realize it's different from a master password lockdown, but I found in the manual a way to reset settings with a jumper (no jumper actually needed, any small piece of metal worked). It worked!

System time

Posted Jul 18, 2025 21:03 UTC (Fri) by Lwnkhz (guest, #178382) [Link] (4 responses)

Not possible on TPM protected systems

System time

Posted Jul 18, 2025 21:18 UTC (Fri) by mjg59 (subscriber, #23239) [Link] (3 responses)

The TPM has nothing whatsoever to do with firmware settings or whether they can be reset.

System time

Posted Jul 18, 2025 22:06 UTC (Fri) by aaribaud (subscriber, #87304) [Link] (2 responses)

> The TPM has nothing whatsoever to do with firmware settings or whether they can be reset.

This rather depends on the context, notably whether and how the BIOS is TPM-protected.

System time

Posted Jul 18, 2025 22:54 UTC (Fri) by mjg59 (subscriber, #23239) [Link] (1 responses)

No, it doesn't. There's no such thing as a TPM-protected BIOS and even if there were that would have nothing to do with the firmware variables which are inherently mutable.

System time

Posted Jul 19, 2025 4:48 UTC (Sat) by aaribaud (subscriber, #87304) [Link]

> No, it doesn't. There's no such thing as a TPM-protected BIOS and even if there were that would have nothing to do with the firmware variables which are inherently mutable.

There appears to be such thing as a TPM-protected BIOS: https://trustedcomputinggroup.org/american-megatrends-sup...

And if there is such a BIOS, then when the master password is set, many settings become immutable.