Firmware also controls autofocus, exposure, image processing, noise reduction and other important functions within your camera.Without firmware your camera would not be able to operate.The users (film makers) wanted to be able to have more control over the 5D mark II for video functions.
Please note that some camera models never had new or updated firmware released and therefore new firmware updates may not be listed at all.
Important: You need to know the model of your camera and only use the firmware that is specific to your model.
Your instruction manual will help you find where to look in the menus.
You can check for the latest firmware by looking at the manufactures support and downloads section of their website for your brand and model of camera.
Look for higher version numbers than the one found on your camera.