The call was added in the 1.1 revision of the spec, 1.0 does not have it, and there are some machines out there with a TPM2 and a UEFI firmware that only supports version 1.0, so the call fails in those cases. Check the reported version before calling get_active_pcr_banks(). See Table 4 in section 6.2 of the TCG EFI Protocol Specification: https://trustedcomputinggroup.org/wp-content/uploads/EFI-Protocol-Specification-rev13-160330final.pdf Fixes: f326c5c47 (commands/bli: Set LoaderTpm2ActivePcrBanks runtime variable) Signed-off-by: Luca Boccassi <luca.boccassi@gmail.com> Reviewed-by: Andrew Hamilton <adhamilt@gmail.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>