Merging application core and net core hex files

[parksj10]

Is there any othere way than mergehex to merge application core and netcore hex files? I'm not sure if I'm following correctly, but it seems like it might be possible through kconfig (e.g. in this multiimage build section).

The goal is to have a single merged.hex file that I can distribute to hardware engineers for flashing and testing (rather than having to have them figure out/follow directions for flashing two separate images)

-- runners.nrfjprog: Flashing file: /Users/josh/Code/ebb/alpha-fw/build_nrf5340_debug/merged_CPUNET.hex
[ #################### ]   8.623s | Erase file - Done erasing                                                          
[ #################### ]   1.117s | Program file - Done programming                                                    
[ #################### ]   1.139s | Verify file - Done verifying                                                       
Applying pin reset.
-- runners.nrfjprog: Board with serial number 1050023050 flashed successfully.
-- west flash: using runner nrfjprog
-- runners.nrfjprog: reset after flashing requested
-- runners.nrfjprog: Flashing file: /Users/josh/Code/ebb/alpha-fw/build_nrf5340_debug/merged.hex
[ #################### ]   6.313s | Erase file - Done erasing                                                          
[ #################### ]   1.326s | Program file - Done programming                                                    
[ #################### ]   1.302s | Verify file - Done verifying   

[Sigurd]

Hi!

Depending on what SDK version you are using, you might have a merged_domains.hex  , that contains both APP and NET core image. Program it like this:

nrfjprog -f NRF53 --program zephyr/merged_domains.hex --recover --verify

PS: you need at least nrfjprog version 10.21.0 or newer.

[parksj10]

These are all the files I see. I have SDK 2.9.0 installed... Considering I'm not getting the merged_domains.hex, I'm not sure it matters, but I have nrfjprog 10.24.2

[Sigurd]

Hi!

parksj10 said:

These are all the files I see. I have SDK 2.9.0 installed.

In the later versions, including 2.9.0, the merged_domains is no longer used.

https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/releases_and_maturity/migration/migration_sysbuild.html#filename_changes

So then mergehex is the only option.

[parksj10]

Thanks, why was this removed? To confirm, I now have to either manually merge the hex files or flash two separate ones?

[Sigurd]

Hi!

parksj10 said:

To confirm, I now have to either manually merge the hex files or flash two separate ones?

Correct.

parksj10 said:

why was this removed? 

For a long time nrfjprog did not support flashing this kind of multi-core hex file to both cores at the same time, it's just in a more recent version this support was added.

The build system /west actually never supported it, and it splits the merged_domains into seperate hex files before flashing them when using nrfjprog as runner. So sysbuild did not consider creating merged_domains.hex as relevant. Maybe we can add merged_domains.hex back in a future version.