The present disclosure generally relates to using a single firmware slot in a slower boot media while temporarily leveraging high speed media and dual boot designs to allow booting into a cached copy of firmware to guarantee power safety while writing the single firmware slot on the slower boot media. The device boots up with original firmware stored in a first non-volatile memory device when powered on. The device then checks a second non-volatile memory device for new firmware. If there is new firmware stored in the second non-volatile memory device, the device loads the new firmware into a volatile memory device and reboots with the new firmware. The device then writes the new firmware to the firmware slot of the first non-volatile memory device. If the device experiences a power cycle while writing the new firmware, the device can reboot with a cached copy of the new firmware.