on trying to update firmware on nrf52832 over the air I'm getting the error message INSUFFICIENT_RESOURCES.
Actually I don't understand the error message because if I generate the bootloader settings page for the firmware image and flash both hex files separately (the firmware and the bl settings page) everything works as expected. For our customers I wan't this firmware image to be updated using DFU OTA so I generate a zip file with nrfutil:
nrfutil pkg generate --hw-version 52 --application-version 1 --application myfirmware.hex --sd-req 0x8c --key-file ../keys/private.pem update_file.zip
I need to say that since our last update we added a ton of features and a huge binary blob of about 60 kB so that the resulting image has a size of 348 kB. Regarding the nrf52 memory layout the firmware image starts at 0x1f000. The bootloader starts at address 0x78000. So from my understanding the firmware exactly fits into the space between 0x1f000 and 0x78000. Correct me if I'm wrong. Do I miss something? Are there any restrictions regarding file size and DFU OTA update?
You are correct that the flash requirement of SoftDevice s132 version 3.0.0 (which is the one you use for generating the DFU zip with --sd-req 0x8c) is 124 kB (0x1F000 bytes). That means the application starts at 0x1F000.
You are also correct that the bootloader (usually) starts at 0x78000.
There are mainly two things that might reduce what size is possible for an application over DFU:
Thanks. I had the exact same issue and I had forgotten to include the 3 pages of application data in my code size calculation. After decreasing the code size, DFU works.