Laying the strong bedrocks

Connectivity is a basic requirement for Software systems which are designed today. A connected system means heightened security risk, due to enlarged exposed surface to external systems. With time, some weakness will be found, and the software update would be required.

A connected system need to respond to wider network it is part of interactions. The network is not static, new protocols are being added, new kind of systems are needed to be communicated with, therefore a connected system will need new features to remain relevant and provide the value in a networked system.

Therefore, update system is an integral part of the system design, ignore it on your own peril. Lay the founding stone for how you will update the system in field.

Should it be symmetrical or asymmetrical flash map?

How granular should be updated ? Full image, partition, a single file.

Before working on putting together the distribution, have a plan for your updater. If the updater is slapped on as an afterthought, it will be a pain-point forever.