Firmware

The programs and data components of a cryptographic module that are stored in hardware within the cryptographic boundary and cannot be dynamically written or modified during execution.
SOURCE: FIPS 140-2

Computer programs and data stored in hardware – typically in readonly memory (ROM) or programmable read-only memory (PROM) – such that the programs and data cannot be dynamically written or modified during execution of the programs.
SOURCE: CNSSI-4009