Usable flash size / maximum partition size

[bienvenu]

Hi,

I'm wondering whether we need a 32mbit flash, or if a 16mbit flash will suffice. For my application, I shouldn't need to store large chunks of data, just two OTA partitions. I see I need to set aside the first 64KB for the bootloader/partition table etc, and that app partitions need to be 64KB aligned.

What is the maximum usable partition size for an application partition? I see many examples with 1MB factory/OTA partition sizes, can these be larger (say, 2MB)? Is this likely to be necessary/useful in a design, or is that overdesign and a waste of flash space/cost?

For maximum usage of the flash, could a 16Mbit flash with this table work?

Code: Select all

0x000000 64KB of bootloader/partition etc
0x010000 64KB free
0x020000 960KB of factory page
0x110000 960KB of OTA page

Bonus question: is there a necessity for a factory page (written once, never updated), or are we able to just define two OTA pages?

Thanks!