Legacy DFU procedure fails when the firmware image is signed

RE: Legacy DFU procedure fails when the firmware image is signed

Einar Thorsrud — Thu, 05 Aug 2021 06:34:00 GMT

[quote user="tjhasan"]Just to be clear, Legacy DFU doesn't support any sort of image verification?[/quote]

Yes, that is correct.

RE: Legacy DFU procedure fails when the firmware image is signed

tjhasan — Wed, 04 Aug 2021 16:08:23 GMT

I'm simply experimenting a bit with Legacy DFU to see how it works so on and so forth. I figured that since nrfutil 0.5.2 has the option to generate a private key as well as the option to use that private key to generate a firmware image .zip file, the generated file can be used to conduct a firmware update.

Just to be clear, Legacy DFU doesn't support any sort of image verification?

RE: Legacy DFU procedure fails when the firmware image is signed

Einar Thorsrud — Wed, 04 Aug 2021 15:45:53 GMT

I see. Why do you try to sign the image? The legacy bootloader does not use image verification. You should use unsigned images generated with nrfutil 0.5.x together with the legacy bootloader. Signed images are only usable with the newer secure bootloader.

RE: Legacy DFU procedure fails when the firmware image is signed

tjhasan — Wed, 04 Aug 2021 15:07:30 GMT

I am using nrfutil 0.5.2 to generate the image, sorry I should have mentioned that. The problem is still the same.

RE: Legacy DFU procedure fails when the firmware image is signed

Einar Thorsrud — Wed, 04 Aug 2021 11:49:06 GMT

Hi,

You cannot use signed images with the legacy bootloader. You need to use nrfutil 0.5.x to generate the image. (See list of compatible nrfutil versions and SDK versions here).