nRF91: questions related to merged image (App , smp & mcuboot)

[kk2mkk]

Hi,

Sorry for putting so many questions in to single thread :)

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I am looking for information on what all images been integrated to zephyr/merged.hex, can you point to the scripts which does this?

Whenever i choose board = nrf9160_pca10090ns, automatically the smp is been built and merged to zephyr/merged.hex, is there anything else been merged to  the final image?

Can I flash the app and spm separately using jlink?

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Coming to the sample “http_application_update” there are three images clubbed to merged.hex i.e App + spm + mcuboot, Can you please point to the documentation/scrips which dictates where a particular image needs to be placed?

regards

KK

 

[kk2mkk]

HI Hakon,

I have got only partial answer to my questions, can you point me to the documentation where it described the memory map of bootloader, spm and sample app(http_application_update) are build, and how to control the allocation of memory regions?

regards

KK

[Hakon]

You can change the memory allocation of SPM, mcuboot; and application by using the partition manager. You will find the documentation here.

[Hakon]

One more update. I was able to flash the images separately by running

nrfjprog -f nrf91 --program mcuboot/zephyr/zephyr.hex --sectorerase
nrfjprog -f nrf91 --program spm/zephyr/zephyr.hex --sectorerase
nrfjprog -f nrf91 --program zephyr/mcuboot_primary.hex --sectorerase
nrfjprog -f nrf91 --program zephyr/zephyr.hex --sectorerase
nrfjprog -f nrf91 --program zephyr/app_signed.hex --sectorerase

in this specific order. Then after that the application would boot properly.

[kk2mkk]

Image	Address	Location
1	0x00000000
	0x00008960	mcuboot/zephyr/zephyr.hex
2	0x00010200
	0x00017ff0	spm/zephyr/zephyr.hex
3	0x00010200
	0x0002a77a	zephyr/mcuboot_primary.hex
4	0x0001c200
	0x0002a770	zephyr/zephyr.hex
5	0x00010000
	0x0002a8c0	zephyr/app_signed.hex

I did some analysis on where the individual images address are mapped in the flash and i found that only 1& 5 images are sufficient for your application to get up and running.

Image 5 is combination of images 2,3 & 4.

As per the nrf9160_pca10090_common.dts file the SPM should be places @0x00010000 and user app @0x00040000 but here its starting @0x0001c200, can you help me understand what going on there?

[Hakon]

kk2mkk said:

can you help me understand what going on there?

 There might be some overlap between the files, but that should be taken care of by the mergehex script with the --overlap=replace flag included if I'm not mistaken.

[kk2mkk]

Hakon said:

can you help me understand what going on there?

My questions is why my application starting form @0x0001c200, as per the .dts the unsecured application image should start form @0x00040000???

[Hakon]

The .dts file you're referring to does not show the correct memory placement. You can run "ninja rom_report" from build folder to get the memory layout, or you can look at the linker script.

[kk2mkk]

Thanks, I think the is no documentation available for whatever we discussed above, it would be great you can add some.

rom_report when mcuboot is enabled

More options can be learnt from build.ninja file located in the build folder.

MCUboot regions can be altered from mcuboot's menuconfig

<builld dir>\mcuboot>ninja menuconfig

Can you please help me understand what each of the macros above (highlighted in yellow) stands for?

regards

KK

[Hakon]

MCUBOOT is the mcuboot image. MCUBOOT_SCRATCH is the space dedicated for image swapping. MCUBOOT_STORAGE is for storing images. MCUBOOT_PAD is an optional trailer on the image that indicates that the image should be considered an upgrade. Writing this image in the secondary slot will then cause the bootloader to upgrade to it.