There is disclosed in one example, a system-on-a-chip (SoC), including: a processor core; a fabric; an intellectual property (IP) block communicatively coupled to the processor core via the fabric, the IP block having a microcontroller configured to provide a microcontroller architecture; a firmware load interface configured to provide a standardized hardware interface to the microcontroller architecture, wherein the standardized hardware interface provides an architecture-agnostic mechanism to securely load a firmware to the intellectual property block; and logic to provide a loader to load a firmware to the IP block via the firmware load interface.