The separation between two or more stages implies that the symbols of the two executables are linked into different .elf files. Debugging using both sets of symbols is still possible, but the symbols from both .elf files must be loaded in the debugger in two steps. When the debugger is executed using the symbols from the bootloader, by adding the bootloader.elf file as an argument, or using the file command from the GDB command line, the symbols of the bootloader are loaded in the symbol table for the debugging session. To add the symbols from the application .elf file, we can add the corresponding .elf at a later stage, using add-symbol-file.
The directive add-symbol-file, unlike file, ensures that the symbols ...
