MBR identical in future SoftDevice versions?

RE: MBR identical in future SoftDevice versions?

Einar Thorsrud — Mon, 30 Apr 2018 10:36:12 GMT

Yes, the MBR uses only the first sector, which is address 0 to 0x1000 for the nRF52 series. You can see the details in the Master Boot Record and bootloader chapter in the SoftDevice specification.

RE: MBR identical in future SoftDevice versions?

henriksern — Mon, 30 Apr 2018 10:12:51 GMT

Thank you Einar, that's good news! Can you verify that I'm correct when I'm saying that the MBR is stored in (and only in) the first sector? (0x0 -> 0x1000)?

RE: MBR identical in future SoftDevice versions?

Einar Thorsrud — Mon, 30 Apr 2018 08:59:25 GMT

Hi Henrik.

The intention is that the MBR should never change in the lifecycle of a product, and that it should never be upgraded via DFU. The DFU examples we provide in the SDK strips the MBR from the SoftDevice before upgrading the SoftDevice via DFU, so that it is never overwritten. As you write, overwriting the MBR could brick the device if something goes wrong.

Nothing lasts forever, so I cannot guarantee that the MBR in the SoftDevice/SDK will never change. What I will say though, is that even if there is a new MBR at some point, you should only use it for new products, not for existing products in the field.

RE: MBR identical in future SoftDevice versions?

henriksern — Mon, 30 Apr 2018 07:32:17 GMT

EDIT: Just to add, we are using SDK 13 with SoftDevice S130 4.02