buttonless DFU issue loading with jlink

RE: buttonless DFU issue loading with jlink

Vidar Berg — Wed, 23 Oct 2019 14:53:03 GMT

The MBR data is included in the bootloader image and can easily get overwritten if you, for instance, flash the Softdevice after programming the bootloader. This is an unfortunate limitation in SDK 15.3.0. But it is fixed in the SDK 16.0.0. From the release notes:

-Bootloader start address is now placed in UICR at compile time, and the MBR page is
populated at runtime. This is to mitigate problems with flashing
where the MBR was erased.

The SES projects will load the Softdevice hex along with the project by default. So this is probably why the data gets overwritten in this case. I suggest removing the Softdevice load option for the application project. That should fix the problem.

RE: buttonless DFU issue loading with jlink

BEplane — Wed, 23 Oct 2019 14:52:19 GMT

Thank you Belenie for posting this for me, I was having difficulty posting and have since figured out a solution to posting.

I have created a post, which makes this post a duplicate. My post with updated information can be found,

https://devzone.nordicsemi.com/f/nordic-q-a/53531/nrf52840-ble-buttonless-dfu-sdk-15-3-0-example-memory-issue

Thank you,

RE: buttonless DFU issue loading with jlink

Belenie — Wed, 23 Oct 2019 03:49:45 GMT

I will say It is not clear to me what is being written to the MBR page when the app is being loaded. I am under the impression that I do not want to be writing anything to the MBR page while flashing the app.

Is the application, or softdevice writting to the MBR?

Why would I want to change the addresses to the alternative UICR addressed, instead of removing the writing happening to the MBR page? it seems that the writing should not be happening?

RE: buttonless DFU issue loading with jlink

Turbo J — Tue, 22 Oct 2019 14:19:50 GMT

[quote userid="71257" url="~/f/nordic-q-a/53533/buttonless-dfu-issue-loading-with-jlink"]Question: Why is the project writing to 0x0 – 0xfff?[/quote]

Because these are documented locations for bootloader address. I think you are supposed to write to the MBR page without a page erase, but have no idea how to tell SES to do that.

Fixed this problem by changing these addresses in the linker script to the alterative UICR addresses (NRFFW[0] and NRFFW[1] in UICR).

For LD this looks like:

 uicr_bootloader_start_address (r) : ORIGIN = 0x10001014, LENGTH = 0x4
 uicr_mbr_params_page (r) : ORIGIN = 0x10001018, LENGTH = 0x4