RE: Firmware Updates over UART w/Custom board using NRF52820, No Buttons, no LEDs

Hieu — Wed, 15 May 2024 14:00:50 GMT

I see, that means that Access Port Protection was originally being enabled and was then disabled.

No worries about that then.

RE: Firmware Updates over UART w/Custom board using NRF52820, No Buttons, no LEDs

JeffCat — Wed, 15 May 2024 13:54:34 GMT

Thank you Hieu, I will look over those 3 resources

"unsecured" - The programmer in NRF Connect indicated the microcontroller was secured (reading flash over the programming interface is denied). Unsecure is a process to erase the entire flash area, which would include erasing MCUBoot, or any other images. Though it appears MCUBoot is included in the smp_svr sample's merged.hex.

RE: Firmware Updates over UART w/Custom board using NRF52820, No Buttons, no LEDs

Hieu — Wed, 15 May 2024 13:21:37 GMT

Hi JeffCat,

[quote user=""]I've tried starting the SDK17 secure_uart bootloader sample, with a custom board, and modified makefile (micro & no FPU), modified the linker according to case about nRF52820 uart dfu. And was unable to start communication. Is another image such as MCUBoot supposed to be at offset 0? Wheres the image?[/quote]

First of all, I would like to address this point. Unless you have a strong reason to do so, you shouldn't mix SDK. Since you are using the nRF Connect SDK, you shouldn't try to make the nRF5 SDK Secure Bootloader to work.

It is possible, and I can answer your questions about it, but I recommend against this.

[quote user=""]But I'm both overwhelmed by the number of options (DFU, SMP, and/or MCUMGR) , and unable to find a reliable starting point. I think my question boils down to:
What are the minimal requirements to allow an initial, and future firmware upgrades over UART?[/quote]

I understand being overwhelmed by the number of configurations. To keep things more manageable, please just keep the configurations at their default value. The solution is meant to work well with that.

To help ease you into the topic, may I suggest taking a look at Lesson 8 of our free online course on the nRF Connect SDK?

My colleague Sigurd also has two unofficial samples that demonstrate DFU over UART:
mcuboot_smp_uart at main · hellesvik-nordic/samples_for_nrf_connect_sdk (github.com)
serial_recovery at main · hellesvik-nordic/samples_for_nrf_connect_sdk (github.com)

[quote user=""]I've unsecured the NRF52820 due to a poor programmer connection... Do I have to re-install any additional images?[/quote]

Could you please explain the problem in further details? I am afraid I don't understand what "unsecured" means here.

Hieu