```ruby
class Spree::FirmwareController < Spree::Admin::BaseController

  class FirmwareParams
    def self.build( params )
      params.require( :firmware ).permit( :version, :file )
    end
  end

  def index
    @firmware_list = Spree::Firmware.order( 'version DESC' )
  end

  def new
    @firmware = Spree::Firmware.new
  end

  def create
    if params[:firmware][:file]
      file = params[:firmware][:file]
      params[:firmware].delete :file
    end

    @firmware = Spree::Firmware.new( FirmwareParams.build(params) ) do |t|
      t.file = file.read if file
    end

    if @firmware.save
      redirect_to firmware_index_path
    else
      render action: :new
    end
  end

  def destroy
    @firmware = Spree::Firmware.find params[:id]
    @firmware.destroy
    redirect_to firmware_index_path
  end

  def serve
    @firmware = Spree::Firmware.find params[:id]
    send_data @firmware.file, type: 'application/octet-stream', filename: file_name, disposition: 'inline'
  end

  private

  def file_name
    "app_mt_update-#{@firmware.version}.bin"
  end
end
```

Fix autoloader failing to include firmware module
user
```ruby
require 'firmware'

module Spree
  class FirmwareController < Spree::Admin::BaseController

    class FirmwareParams
      def self.build( params )
        params.require( :firmware ).permit( :version, :file )
      end
    end

    def index
      @firmware_list = Spree::Firmware.order( 'version DESC' )
    end

    def new
      @firmware = Spree::Firmware.new
    end

    def create
      if params[:firmware][:file]
        file = params[:firmware][:file]
        params[:firmware].delete :file
      end

      @firmware = Spree::Firmware.new( FirmwareParams.build(params) ) do |t|
        t.file = file.read if file
      end

      if @firmware.save
        redirect_to firmware_index_path
      else
        render action: :new
      end
    end

    def destroy
      @firmware = Spree::Firmware.find params[:id]
      @firmware.destroy
      redirect_to firmware_index_path
    end

    def serve
      @firmware = Spree::Firmware.find params[:id]
      send_data @firmware.file, type: 'application/octet-stream', filename: file_name, disposition: 'inline'
    end

    private

    def file_name
      "app_mt_update-#{@firmware.version}.bin"
    end
  end
end
```
assistant