Provided herein may be a storage device including a memory device, and a memory controller including a plurality of cores. The memory controller may load a boot loader image for firmware update running in a memory of a core arbitrarily selected from among the plurality of cores, receive a new firmware image from a host in response to the boot loader image that is executed in the selected core, and update a firmware image stored in a memory of each of the plurality of cores with the new firmware image.