RE: update nrf dfu bootloader from SDK15 with bigger one

Turbo J — Fri, 06 Mar 2020 15:41:47 GMT

[quote userid="87378" url="~/f/nordic-q-a/58811/update-nrf-dfu-bootloader-from-sdk15-with-bigger-one"]Does the SD_MBR_COMMAND from the softdevice not accept a target address to activate a bootloader, which is bigger than the old one?[/quote]

Nope.

Reason is simple: Any power loss (or other unexpected problem/reset) during the size change could brick the device, espacially when UICR or MBR needed an erase cycle.

You really want to do this with an jlink debugger/programmer via SWD.

It is THEORETICALLY possible to write an intermediate bootloader that changes the address from 0x7000 to 0x5000 since that would only need a bit flip in 1->0 direction - which is possible without an erase cycle.

But it would require at least some free space in the old bootloader area in order to be able to make this change somewhat safely - and you would also have to worry about FDS data, which is normally stored right below the bootloader space.