Create a debug menu

ThomasWinwood · Apr 21, 2019

I learned about windows and list menus today, and I've written a short-ish tutorial on how to add a debug menu to pokeemerald using the same hooks Game Freak used for their own debug menu in order to try and help others in turn. BBcode depresses me, so I've hosted it as a gist.

If you're a better C programmer than me or more familiar with the pokeemerald codebase, I'd like to know about any ways in which I can do what I'm doing more efficiently. In particular, having three different lists which need to be kept in sync strikes me as odd; I considered writing a macro, but then I remembered how C's macro system works and decided not doing that sounded way more fun.

SidDays · May 30, 2019

Thanks a lot for the tutorial! I'm still in the process of understanding it completely, but for now I've just added your code as it is, and I'm facing this error:

Code:

`Debug_ShowMainMenu' referenced in section `.text' of src/field_control_avatar.o: defined in discarded section `.text' of src/debug.o
make: *** [Makefile:204: pokeemerald.elf] Error 1

Do you have any idea why that would be happening?

ThomasWinwood · May 30, 2019

You need to add src/debug.o to the linker script. It looks like I forgot to mention that, possibly because I replaced it with one that didn't include filenames individually by name. (Presumably eventually someone will fork pokeemerald to make it more suited to ROM hacking, and you won't have to do this anymore.)

1. Open ld_script.txt.
2. Find the line src/start_menu.o(.text);; add a new line after it that says src/debug.o(.text);.
3. Find the line src/start_menu.o(.rodata);; add a new line after it that says src/debug.o(.rodata);.

SidDays · May 30, 2019

ThomasWinwood said:
You need to add src/debug.o to the linker script. It looks like I forgot to mention that, possibly because I replaced it with one that didn't include filenames individually by name. (Presumably eventually someone will fork pokeemerald to make it more suited to ROM hacking, and you won't have to do this anymore.)

1. Open ld_script.txt.
2. Find the line src/start_menu.o(.text);; add a new line after it that says src/debug.o(.text);.
3. Find the line src/start_menu.o(.rodata);; add a new line after it that says src/debug.o(.rodata);.

Thanks a lot! That worked ?????? There's only a minor problem where unless I open the Start Menu once the palette for the border is garbled, but I don't think that should be an issue and instead I'll work on actually adding debug options to this

SidDays · Jul 20, 2019

Sidrk said:
Thanks a lot! That worked �� There's only a minor problem where unless I open the Start Menu once the palette for the border is garbled, but I don't think that should be an issue and instead I'll work on actually adding debug options to this

I was able to fix this by looking at start_menu.c and map_popup_menu.c: the issue seems to have been caused by 1) the game not loading the gfx/palettes for the border and 2) the map popup obscuring the debug window since it's on the left

To fix the problem, add the Map Popup Header

Code:

#include "map_name_popup.h"

to the top, then add these lines

Code:

HideMapNamePopUpWindow();
sub_81973A4();

Above the lines indicated by // create window.

The function sub_81973A4(); doesn't seem to have been renamed, but this is what it looks like, in case anyone was wondering:

Code:

void sub_81973A4(void)
{
    LoadMessageBoxGfx(0, DLG_WINDOW_BASE_TILE_NUM, DLG_WINDOW_PALETTE_NUM * 0x10);
    LoadUserWindowBorderGfx(0, STD_WINDOW_BASE_TILE_NUM, STD_WINDOW_PALETTE_NUM * 0x10);
}

I spent an obscene amount of time trying to figure this out, but I intend to make a general purpose debug menu at some point that romhackers can use for easy testing.

Yknr · Jul 26, 2019

how to you make a build without the debug menu once you implement it? I tried just plain make, added an else clause to debug in the makefile that sets the flags to 0 if no param is sent. each time the compiler just either said "nothing to do for 'rom'", or it copied cached data from pokeemerald.elf. I even tried deleting the elf file, but the code constrained under the debug flags is still functional in game. I'm nowhere near anything worth putting out yet, but I thought I would see if my code worked without the debug functions or if I had botched something. glad I caught it now rather than later, but I still have no idea how to fix it.

ThomasWinwood · Jul 26, 2019

Yknr said:
added an else clause to debug in the makefile that sets the flags to 0 if no param is sent

I don't have a repo set up to check, but this isn't necessary and is probably the source of the problem you're having. #if DEBUG isn't checking whether DEBUG is equal to 1 - it's checking whether it's set at all. Setting DEBUG to 0 is still setting it, so your debug code is always compiled.

ThomasWinwood · May 15, 2020

Just to let y'all know that

1. This has been translated into Spanish.
2. This has been added to the pokeemerald wiki, which will probably be updated more regularly because more people than just me can update it.

Jaizu · May 15, 2020

This is a very good resource, thanks for sharing.
I would suggest to make a standard one (changing vars, setting flags, giving mons, changing bgm...) as a default one instead a blank one but hey, it's still a good post.

Rappe · Nov 20, 2021

Is there a way to implement this for pokefirered?

I imported all of the code to the same files and was able to get it to compile after some tweaking, but the debug menu won't open. The start menu just opens like normal.

Create a debug menu

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ThomasWinwood

SidDays

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ThomasWinwood

SidDays

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SidDays

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Yknr

ThomasWinwood

ThomasWinwood

Jaizu

Average rom hacker

Rappe