This commit provides definition and declaration of GPT verification functions - namely gpt_verify_headers() and gpt_verify_partitions(). The former is used to only check CRC32 of GPT's header and PTEs. The latter examines each partition entry and compare attributes such as: name, start offset and size with ones provided at '$partitions' env variable. Signed-off-by: Firefly <service@t-firefly.com> Reviewed-by: Firefly <service@t-firefly.com> Reviewed-by: Firefly <service@t-firefly.com>