I'm aware I'm extremely late to the party here, but having just been through the same - this may help somebody.
In Studio, go to the application project's
Programming Settings, change from
Erase entire chip to
Now, flash your bootloader and application manually through the Device Programming interface (Ctrl+Shift+P) or
atprogram, or whatever other means you're using, then simply start a debug session as normal. However, at this point you will not be able to debug the bootloader, only the application. To debug both in a single session, read on below.
Note, it's worth combining both the bootloader and application hex files into one single file, using srec-cat as an automated post-build action in Studio.
In the application project
Properties, go to
Build Events and add the following in the
Post-build event command line.
srec-cat <path_to_bootloader_outputs>\boot.hex -Intel <path_to_application_outputs>\app.hex -Intel -o <path_to_new_combined_image>\combined_image_name.hex -Intel
To be able to debug both the bootloader and application now in a single debug session, navigate to the application
Additional modules, and add the .elf file for the bootloader, ensuring you tick
Only debug symbols (no writing), whilst doing so.
If you now program the combined hex file containing both the bootloader and application, then start a debug session with
Skip programming enabled, you will be able to symbolically debug both the bootloader and application, as if they were one.