[NRF52] Question about the MBR and SD dependence

[shaba]

Hey folks,

Is there any dependence between the MBR and the SD version? The reason I ask is because we are working on a product that will be able to update the softdevice as well as the app portions of the image while ideally retaining the MBR.

Do you guys see any issues with this method? We are currently running the 2.0.0 version of the 332 SD with the 2.0.0 MBR. I was going to try downgrading just the first page of flash to the old MBR, but figured I would pose the question in parallel.

[bjorn-spockeli]

No, the MBR is SoftDevice independent, so the approach you're describing should work just fine. In fact, this is how we do it in our bootloader, the MBR is never updated during DFU, just the Softdevice.

-Bjørn

[JeanMBoones]

I have a similar question and would like clarification. The MBR and the SD are packaged/delivered together in the same binary.

1. If there is no dependency, then why package them together?
2. How exactly are the MBR and SD linked/coupled? Is it simply via configuration registers that can be updated if necessary or is there anything in actual executable code that is directly linked into the MBR regarding the SD?

Thanks,