Feasibility of Two-Stage Bootloader

[Chance]

I would like to use the Arduino Nano 33 BLE with MCUBoot and MCUMGR for FOTA. I am wondering if it is possible to use a two-stage bootloader (first stage Arduino BOSSAC, second stage MCUBoot) for FOTA. As I understand it the Flash must be partitioned in a specific way to use MCUBoot. Is it possible to reconcile the device tree, or mcuboot, with this bootloader configuration? If not, I will flash the mcuboot bootloader via the SWD interface on the back of the Nano and use the normal devicetree configuration.  

[Einar Thorsrud]

Hi,

I do not have specific experience with Arduino BOSSAC, but there is generally no problem suing two bootloader stages where MCUBoot is the second stage. That is an approach used in the nRF Connect SDK, where you can have an immutable B0 bootloader, which validates and starts MCUBoot. See Secure bootloader chain.