A firmware controller is configured to enhance or modify the processing capabilities of an imaging device by creating custom firmware for a particular imaging job. The firmware controller does so by dynamically linking firmware processing stages resident on the imaging device with additional firmware processing stages stored at a host device to form a sequence of firmware processing stages. The firmware controller then controls execution of the custom firmware by passing the output of each stage to the input of the next stage in the sequence. The firmware processing stages resident at the imaging device and the additional firmware processing stages stored at the host share a commonly defined interface for inputting data and/or control signals to and outputting data and/or control signals from each stage, which allows the firmware stages to be combined in a variety of different sequences.