[thudson]

The threat model that LinuxBoot is addressing is different form SecureBoot and it can use the well known, normal Linux tools rather than the unconventional UEFI ones.

The Heads runtime can do things like use TPMTOTP to attest to the user that the firmware is unaltered and includes gnupg to verify the kernel and root filesystem signatures with the user's own key.

For cloud systems a LinuxBoot runtime can use the TPM or other trusted hardware to remotely attest to the client's own provisioning server that the configuration is unchanged, and since it is reproducibly built, that the firmware is what the user expects. This is significantly more trustworthy than the binary blobs and non-reproducible UEFI firmware on most servers.