Abstract: Firmware can be built to be capable of generating and outputting trace data, during execution, to assist in debugging firmware problems without substantially slowing operation of the firmware and without potentially disclosing secret information associated with the firmware. The firmware (e.g., BIOS) can output hash digests of various modules within the firmware, which can be compared with a pre-established mapping table to identify modules that successfully completed or did not successfully complete during execution of the firmware, such as during a startup procedure. The hash digest can be a one-way hash, which can be rapidly executable during operation of the firmware and can keep the code of the modules hidden from unauthorized reverse engineering.