Abstract: In some aspects, the HVAC field device described herein includes: a housing; an HVAC functional device; a non-volatile memory unit including: a first set of computer-executable instructions in a first memory partition configured to execute an operating system; and a second set of computer-executable instructions in a second memory partition configured to execute an application module, wherein the application module is configured to control operation of the HVAC functional device; a volatile memory unit; and at least one processor configured to: execute the operating system in a first memory region of the volatile memory unit and execute the application module in a second memory region of the volatile memory unit, wherein the application module is prevented from accessing the first memory region of the volatile memory unit.