Use mbr instead bootloader

[Vladimir]

Hi. I have several questions about mbr.

1). Will mbr finish to write after unexpected power off?

2). Can I copy softdevice + application or only application using sd_mbr_command_copy_sd?

I can't use bootloader with communication interface because of some reasons. Application now can download the new firmware into buffer section. Will I need to use booloader just to copy from buffer (app + sd or app) or I can use only MBR?

[Hung Bui]

Hi Vladimir,

1. No it won't be able redo the flash operation if it's interrupted by power reset or other type of reset. There is no parameter store in flash when calling sd_mbr_command_copy_sd. Parameter is stored in flash when calling nrf_dfu_mbr_copy_bl() but this API can't be used to swap application.

2. Could you let me know why you want to do that ? Note that you need to make sure the swap area to store the image is not overlapping the new sd+application area after swapping.

[Hung Bui]

Ok, so you want to make background bootloader that integrate into your application. My suggestion is to make a small bootloader that take the task of swapping the application (and call the MBR function to swap the softdevice). As mentioned above, the MBR won't store any information about softdevice +application swapping to flash. So if you have a power failure you screwed.

But if you have a bootloader, you can store the information somewhere in the flash and retry if there is a power failure.