MAX 10 compact Remote System Upgrade

In the dual boot mode, CFM0 will be used for one image, while CFM1/2 will be combined and used for the 2nd image. This leaves you only the UFM to store code for Nios. However, the UFM is not that big on MAX10M08. It has only 32KB total (UFM0 + UFM1), but Nios does take lots of memory, as the following blog post suggests:

http://limerick.pulserain.com/2016/09/nios-ii-processor-in-max-10-device.html

And the total BRAM on MAX10M08 is only about 42KB

So my two cents: dedicate all the UFM to your factory image.

For RSU, assume you get the new image from UART (or some other interface). You can write a logic module that gets the nios code through UART, download it to NIos, and run the nios to continue your RSU process.