Devices and methods for securely upgrading devices, such as field upgradeable units, are disclosed. In response to receiving an update object, a device may determine whether a predefined location of memory includes a predetermined value. Based on the value in the predefined location, the device may store the received update object in a verification portion of the memory. After verifying the authenticity of the update object, the device may copy the update object from the verification portion of the memory to an inactive portion. The inactive portion of the memory can be swapped with an active portion of the memory, such that the inactive portion becomes active.