I want to merge my MAX32660 bootloader and application code into a single .msbl that can be flashed at once. How can this be accomplished?
You can use a utility called srec_cat.exe, an open source project available for Windows in binary form, and in source form for most Unix and Linux platforms.
Here’s a link to the project:
https://sourceforge.net/projects/srecord/
The general idea is that you can convert the .ELF files to .HEX using objcopy and then concatenate the .HEX files using srec_cat. You can then use the resulting .HEX file to directly program the flash, or convert it to .BIN or .ELF or whatever else you need.