[ASM & Hex] Where is the asm for exp share battle logic located in pokemon emerald?

[Trinsdar]

I'm want to change the logic related to the exp share, but I don't know where it is located as in the hex address. I'm asking cause I want to fix the exp share logic in pokemon theta emerald renev, to basically reset the exp share to gen 3 behavior, and then also add a key item to do gen 6 behavior. Speaking of the key item exp share, what do these circled parts mean?

Also might this https://www.pokecommunity.com/posts/10099957/ have something? I'm only asking cause it's for ruby, not emerald.

P.s. this exp share thing for theta emerald renev is only going to be done on my personal copy of theta emerald unless I can get permission to upload a patch with the changes.

 

[dearman4]

I can actually help you with this! Someone pointed me in the direction of a Gen VI EXP Share that is flag toggle-able, here's the routine:

Spoiler:

.thumb
.align 2
no_crash:
ldr r0, [r5]
mov r1, r0
add r1, #0x53
ldrb r0, [r1]

flag_check: @It is responsible for checking if we have activated the flag
push {r0-r2}
ldr r0, flag_number
ldr r2, flag_routine
push {r1-r3}
bl linker
pop {r1-r3}
cmp r0, #0x1 @Compare the flag with 0x1 (on)
bne routine_off
pop {r0-r2}

main:
@Check the slot and save it in a variable.
push {r3-r6}
ldr r6, slot_var @Load the pokemon slot in r3
ldrb r3, [r6]
ldr r4, is_egg_party
mov r5, #0x64
mul r5, r5, r3 @Calculate the positions to be advanced
ldrb r4, [r4, r5] @Load on r4 the byte egg / not
cmp r4, #0x6
beq pokemonIsEgg
mov r2, #0x1
b update_slot

pokemonIsEgg:
mov r2, #0x0 @Set r2 to 0 (will not win exp)

update_slot: @Update and reset the slot value
add r3, #0x1
cmp r3, #0x6
bne end
mov r3, #0x0

end:
strh r3, [r6]
pop {r3-r6}
push {r2, lr}
ldr r2, =(0x4A4B4)
ldrh r2, [r2]
lsr r2, r2, #0x1
pop {r2, pc}

return:
push {r2}
ldr r2, return_dir
bx r2

routine_off: @Execute the "original" instructions
pop {r0-r2}
mov r2, #0x1
and r2, r0
b return

linker:
bx r2

.align 2
flag_number:
.word 0x00000[XXX] @Choose the flag number
flag_routine:
.word 0x0809D790 +1 @Routine that checks the flag
slot_var: @Choose a temporary variable (do not use the 0x8000,
.word 0x020275D6 + (0x800[X] * 2) @the game uses it when initializing double bouts
is_egg_party:
.word 0x020244EC + 0x13 @Byte that checks if it is an egg
return_dir:
.word 0x0804A592 + 1 @Return to routine address

And the instructions for customizing the flag number:

Spoiler:

Line 68 - [XXX] we will replace it with an empty flag (or search for .word 0x00000[XXX])
Line 72 - [X] we will replace it with a number except 0 (or search for (0x800[X] * 2)

Paste code into THUMB editor, output to .bin

This will create a .bin file, that is the compiled ASM routine.

Open the .bin file with your preferred hex editor and press Ctrl + A / E (select all) and Ctrl + C (copy)

Now we will open our Pokémon Emerald ROM in a hex editor, go to an offset with empty space inside our ROM and press Ctrl + B.
As I always say, prevention is better than regret. I suggest using an offset that ends in 0, 4, 8 or C. I will use the E3CF80.

Then in our hex editor, we will make the following modifications:
-At offset 04A4BE we will write: 02 21
-At offset 04A634 we will write: 01 20
-At offset 04A58A we will write: C0 46 00 4A 10 47 XX XX XX XX 04 BC
Note : XX XX XX = Offset where we put the ASM routine, converted to a pointer +1.
Example : As I said, I left the routine in E3CF80. E3CF80 + 1 = E3CF81. And if we pass that to pointer, there is 81 CF E3 08

Also an assembled routine with flag 200 and variable 0x8002 used:

Spoiler:

28 68 01 1C 53 31 08 78 07 B4 14 48 14 4A 0E B4 00 F0 22 F8 0E BC 01 28 1A D1 07 BC 78 B4 11 4E 33 78 11 4C 64 25 5D 43 64 5D 06 2C 01 D0 01 22 00 E0 00 22 01 33 06 2B 00 D1 00 23 33 80 78 BC 04 B5 0B 4A 12 88 52 08 04 BD 04 B4 07 4A 10 47 07 BC 01 22 02 40 F8 E7 10 47 C0 46 00 02 00 00 91 D7 09 08 DA 75 03 02 FF 44 02 02 93 A5 04 08 B4 A4 04 00

With this, if your chosen flag is set, the Exp Share will give exp to the whole party and if it is cleared, it will behave normally. Using a Key Item to set a flag is doable I think, though I am not well versed with item creation tbh. Hope this helps!!

 

[9thgenbae]

dearman I just used the assembled hex you provided and followed your instructions. When exp is gained the game reboots. when clearing flag 0x200, exp is gained as usual, so idk what i did wrong but i pasted the asm hex into offset E6E664, and put the pointer as , C0 46 00 4A 10 47 65 E6 E6 08 04 BC. Any help would be appreciated !