[wmf]

GRUB-IMA (based on TCPA) and TBOOT (based on TXT) have been around for a while: http://linux-ima.sourceforge.net/

Google invented their own verified boot system for ChromeOS: http://www.chromium.org/chromium-os/chromiumos-design-docs/v...

Or you could use upcoming UEFI secure boot: http://mjg59.dreamwidth.org/6054.html