The bootloader settings version is used to determine the format of the bootloader settings page, which is different between nRF5 SDK versions.
The following values can be used with the --bl-settings-version option:
| nRF5 SDK version | Bootloader settings version |
|---|---|
| <=12.0 | 1 |
| >=15.3.0 | 2 |
The DFU bootloader settings version supported and used by your selected nRF5 SDK version is listed in the nrf_dfu_types.h file in the bootloader library.
Note
Even though bootloaders compiled from the nRF5 SDK v15.3.0 or later can only use version 2, they can be configured to support a version 1 settings page. When a new bootloader with a version 1 settings page boots, the bootloader translates the settings page to version 2 before booting.
Tip
If you use version 2, you can use the --sd-boot-validation and --app-boot-validation options to generate boot validation for SoftDevice and the application together with the settings page. See the Validation page and the Validation module in the nRF5 SDK documentation for more information.