Intel Extensible Firmware Interface Specification page 117

Status Codes Returned
EFI_SUCCESS
EFI_INVALID_PARAMETER
EFI_UNSUPPORTED
EFI_DEVICE_ERROR
Version 1.02
The timeout has been set.
The supplied WatchdogCode
The system does not have a watchdog timer.
The watch dog timer could not be programmed due to a hardware
error.
12/12/00
is invalid.
Services
99