DFU softdevice and app update

[imo]

Hi.

I am trying to update my Softdevice using DFU.

If I update from S112 to S140, do I have to upload the application as an image built with S140 as well?

And do I need to update the bootloader as well depending on the Softdevice version?

[Einar Thorsrud]

Hi,

The bootloader prevents updates to a SoftDevice of a different type. Moreover we do not test this. That said, it is possible to do a slight change in the bootloader to allow updates to different SoftDevice versions. For that you need to update the bootloader to allow it first, by modifying softdevice_info_ok() in components\libraries\bootloader\dfu\nrf_dfu_validation.c.

You always need to update the BLE bootloader when you update the SoftDevice to a different type or different major version. Note that as the bootloader must be modified first you need to do the update in sequence:

1. Update to the modified bootloader version that support updating to a new SoftDevice type. This should be built for the old/existing SoftDevice.
2. Update bootloader and SoftDevice (S140)