Per Wikipedia, it was coined in 1967 to refer to the glue code that existed at the boundary of hardware and software. Or, in other words, any code which hooks

Per Wikipedia, it was coined in 1967 to refer to the glue code that existed at the boundary of hardware and software. Or, in other words, any code which hooks directly to the hardware on one side and exposes abstractions (like an instruction set) that software can code against on the other. I always assumed "firm" stuck, as in "You'll have a helluva time changing it, because it's the code that has to deal with all the complex electrical engineering stuff." (E.g. processor errata, patched board mistakes via fuse or EEPROM, side effects of power supply undervolting or clock skew, or pre-initialized system murkiness) https://en.m.wikipedia.org/wiki/Firmware#History https://en.m.wikipedia.org/wiki/Firmware#History