Boot failure protection on smartNICs and other computing devices is described. During a power-on stage of a booting process for a computing device, a boot loading environment is directed to install an application programming interface (API) able to be invoked to control operation of a hardware-implemented watchdog. During an operating system loading stage of the booting process, the application programming interface is invoked to enable the hardware-implemented watchdog. During an operating system hand-off stage of the booting process, a last watchdog refresh of the hardware-implemented watchdog is performed, and execution of the boot loading environment is handed off to a kernel boot loader of an operating system. The application programming interface may not be accessible after the hand off to the kernel boot loader.