DFU OTA 52832 error (SELECT command) - works only when running debug version and RTT channel open

RE: DFU OTA 52832 error (SELECT command) - works only when running debug version and RTT channel open

Harry — Wed, 22 Jul 2020 18:32:34 GMT

I agree with you, I am puzzled how come it works fine with debugger, or even running debug build with RTT channel open. Could it be the difference in hard fault handling mechanism caused that?

Btw, I found the article:

https://devzone.nordicsemi.com/f/nordic-q-a/42716/mbr-settings-dfu-settings-backup

It says "Since the params page is only used in the final step of a bootloader update it is ok to also use it as a backup page."

My confusion is how to use MBR Param slot as the backup of Bootloader settings as well.

RE: DFU OTA 52832 error (SELECT command) - works only when running debug version and RTT channel open

Hung Bui — Wed, 22 Jul 2020 10:23:50 GMT

I'm glad that you found the issue.
My understanding is that the MBR check the MBR PARAM page on every booting. And if there is corrupted data at the page it may affect the booting. But I'm not sure why running from debugger can make a difference here.

RE: DFU OTA 52832 error (SELECT command) - works only when running debug version and RTT channel open

Harry — Tue, 21 Jul 2020 16:48:07 GMT

Hi Hung,

Regarding the porting, it's because I need to port the existing Bootloader (for nRF52840 product) to a different product, and this "new" product is running on nRF52832 (perhaps to different platform in the near future).

You're right, I have some modification to the bootloader, not in the bootloader SDK itself, but there is a thin layer on top of it (HW initialization, etc) because it runs on custom board. I am not aware of any modification in the bootloader SDK library part, other than the start address and bootloader settings location.

Ok, I will try to compare to ensure there is no "bizarre" change that I missed.

It's just baffled me why would it runs fine when I opened the RTT channel, or when I run it from debugger. Do you think it stopped working due to hard-fault situation?

UPDATE: I got it work. I found that I forgot to update the MBR PARAM address. It used 52840 address. Btw, I thought MBR Param is written only on Bootloader update.

RE: DFU OTA 52832 error (SELECT command) - works only when running debug version and RTT channel open

Hung Bui — Tue, 21 Jul 2020 08:44:06 GMT

Hi Harry,
From the log I can see that the DFU target would have an assert and stopped working. It's the reason why you get connection timeout before the "Could not write SELECT command: Device disconnected." log.

But I'm not sure why you need to port the code for nRF52840 to nRF52832 ? Wouldn't it work if you just use the bootloader made for nRF52832 that we provided ? Or you have any modification to the bootloader ? Even in that case I would suggest you to start with the bootloader we provided for nRF52832 and then add your modification in.