This will create a pokemon red debug build to the build option. The reason this is not included in base pokered is because there is no Pokemon Red debug ROM to disassemble. Go to your Makefile and edit these lines.

```diff
- roms := pokered.gbc pokeblue.gbc pokeblue_debug.gbc
+ roms := pokered.gbc pokeblue.gbc pokered_debug.gbc pokeblue_debug.gbc

...

  pokered_debug_obj := $(rom_obj:.o=_red_debug.o)
+ pokered_debug_obj := $(rom_obj:.o=_red_debug.o)
  pokeblue_debug_obj := $(rom_obj:.o=_blue_debug.o)

...

  blue:       pokeblue.gbc
+ red_debug: pokered_debug.gbc
  blue_debug: pokeblue_debug.gbc

...

  tidy:
-	rm -f $(roms) $(pokered_obj) $(pokeblue_obj) $(pokeblue_debug_obj) $(roms:.gbc=.map) $(roms:.gbc=.sym) rgbdscheck.o
+       rm -f $(roms) $(pokered_obj) $(pokeblue_obj) $(pokeblue_debug_obj) $(pokered_debug_obj) $(roms:.gbc=.map) $(roms:.gbc=.sym) rgbdscheck.o
	$(MAKE) clean -C tools/

...

  $(pokeblue_obj):       RGBASMFLAGS += -D _BLUE
+ $(pokered_debug_obj): RGBASMFLAGS += -D _RED -D _DEBUG
  $(pokeblue_debug_obj): RGBASMFLAGS += -D _BLUE -D _DEBUG

...

   $(foreach obj, $(pokeblue_obj), $(eval $(call DEP,$(obj),$(obj:_blue.o=.asm))))
+  $(foreach obj, $(pokered_debug_obj), $(eval $(call DEP,$(obj),$(obj:_red_debug.o=.asm))))
   $(foreach obj, $(pokeblue_debug_obj), $(eval $(call DEP,$(obj),$(obj:_blue_debug.o=.asm))))

...

  pokeblue_pad       = 0x00
+ pokered_debug_pad  = 0xff
  pokeblue_debug_pad = 0xff

  pokered_opt        = -jsv -n 0 -k 01 -l 0x33 -m 0x13 -r 03 -t "POKEMON RED"
  pokeblue_opt       = -jsv -n 0 -k 01 -l 0x33 -m 0x13 -r 03 -t "POKEMON BLUE"
+ pokered_debug_opt  = -jsv -n 0 -k 01 -l 0x33 -m 0x13 -r 03 -t "POKEMON RED"
  pokeblue_debug_opt = -jsv -n 0 -k 01 -l 0x33 -m 0x13 -r 03 -t "POKEMON BLUE"