Anyone who wants a more in depth look at how patches keep getting applied to what's essentially a radhard version of the candy shell Mac processors can head over to this link -> https://www-robotics.jpl.nasa.gov/media/documents/Curiosity_...

Leveraging VxWorks you effectively have 3 different ways this software gets updated.

Hot Patch -> Do it live! where you modify the RAM with compiled code so that the changes persist until next reboot.

Cold Patch -> Same as a hot patch, except this time you actually copy the contents into non-volatile memory. VxWorks has a really slim profile and thus this helps keep the size manageable to continue doing science experiments.

Full Updated -> Basically a clean install gets burned in.