The new codehandler! Use this for your gecko modding needs from now on, as it properly handles the cache unlike almost all other codehandlers, and also allows a lot more lines of code than every other codehandler out there!

Download
Source code

UPDATE: @Vega It needs testing, but I made a change that I hope fixes the C0 function call crashes you were having. I need you to test it as I have no memory of which codes caused this issue

THREAD UPDATE (12/28/2020)
Thread has been closed since Stebler has posted the official 200cc Code.

-Vega

200cc Replaces 150cc [JoshuaMK, Leseratte]

Anytime 150cc is detected, the speed is properly modded for 200cc.

Mii Outfit C [TheLordScruffy]

This code enables an extra character button already assigned to Mii Outfit C and allows it to be selected, revealing a perfectly functional Mii Outfit C once you add the models.
The content names, already completely functional but missing the files, are like the other Mii Outfits. Like mc_mii_m for a medium sized male Mii.

NTSC-U
C28235B8 00000005
3BBDFFE4 281D000D
41810018 388030C3
7C9DEC30 73A40001
41820008 3B400004
28000001 00000000
C2823BEC 00000005
3BFFFFE4 281F000D
41810018 388030C3
7C9FFC30 73E40001
41820008 3BA00004
28000001 00000000
04550E54 38600001
047DC684 3BC0001B

NTSC-J
C283D684 00000005
3BBDFFE4 281D000D
41810018 388030C3
7C9DEC30 73A40001
41820008 3B400004
28000001 00000000
C283DCB8 00000005
3BFFFFE4 281F000D
41810018 388030C3
7C9FFC30 73E40001
41820008 3BA00004
28000001 00000000
0454FA38 38600001
047E1D80 3BC0001B

PAL
C283E018 00000005
3BBDFFE4 281D000D
41810018 388030C3
7C9DEC30 73A40001
41820008 3B400004
28000001 00000000
C283E64C 00000005
3BFFFFE4 281F000D
41810018 388030C3
7C9FFC30 73E40001
41820008 3BA00004
28000001 00000000
045500B8 38600001
047E2714 3BC0001B

NTSC-K
C282C3D8 00000005
3BBDFFE4 281D000D
41810018 388030C3
7C9DEC30 73A40001
41820008 3B400004
28000001 00000000
C282CA0C 00000005
3BFFFFE4 281F000D
41810018 388030C3
7C9FFC30 73E40001
41820008 3BA00004
28000001 00000000
0453E110 38600001
047D0AD4 3BC0001B


Assembly Source:
#Mii Outfit C IDs: 0x1C, 0x1D, 0x22, 0x23, 0x28, 0x29

{
#Insert
#NTSC-U 0x808235B8
#NTSC-J: 0x8083D684
#PAL: 0x8083E018
#NTSC-K: 0x8082C3D8
#

  subi r29, r29, 0x1C
  cmplwi r29, 0xD
  bgt- end

  li r4, 0x30C3
  srw r29, r4, r29
  andi. r4, r29, 1
  beq- end

  li r26, 4
end:
  cmplwi r0, 1
}
{
#Insert
#NTSC-U: 0x80823BEC
#NTSC-J: 0x8083DCB8
#PAL: 0x8083E64C
#NTSC-K: 0x8082CA0C
#

  subi r31, r31, 0x1C
  cmplwi r31, 0xD
  bgt- end

  li r4, 0x30C3
  srw r31, r4, r31
  andi. r4, r31, 1
  beq- end

  li r29, 4
end:
  cmplwi r0, 1
}

Check if Time Trials [JoshuaMK]

Use this code to have changes be specific to when you are/aren't in Time Trials.

CC Tracker [JoshuaMK]

Use this code when you want to have changes to the game be CC specific. Tested everywhere except online.

I guess I should make one of these. Hello I am Mew. Not the best at many things (mkw coding) but I do try.

If you don't already have the homebrew channel, follow the guide for your console: Wii Wii U

If you don't already have Riivolution, download it from here and extract the contents of the zip to your apps folder (if you don't already have one, create it on the root of your sd card).

If you haven't already made a GCT, see Vega's guide (other methods exist too, personally I use CheatManager).

First of all you need to put your GCT file in the right place and name it correctly. Create a folder named codes on the root of your sd card (if it doesn't already exist) and place your gct inside. Now you need to rename it to the ID of the game your codes are for (PAL MKWii would be RMCP01.gct, for example - others can be found here).

Next you will need to download a riivolution patch, which you can get here. Extract the contents of this zip file to the root of your SD card. This patch supports any game, not just MKWii.

Now you just need to load the game. Open riivolution, switch to the ocarina page (will be open already if you don't have any other xmls downloaded) and set OCARINA_CODES to Enabled and OCARINA HANDLER to GXDRAW HOOK. Now just press launch and the game will load with your gecko codes applied.

If you ever want to change the codes you're using, just make a new GCT and replace the one in your codes folder.

After reading the WiiBrew article listed below, I wrote this up in ASM really quick. Most likely you will just freeze. Either due to C0 codetype not being able to do IOS function calls or I jacked up the Vector Pointers...

Disconnect Wii Remote Bluetooth [WiiBrew]

Wiibrew C code - https://wiibrew.org/wiki//dev/usb/oh1

This code is to constantly d/c the bluetooth on the Wiimote. So basically it disables the wii remote for your game.

This code is wii-game-universal, as long as you have the game's function addresses for the 3 IOS functions listed in the XYZ values.

X values = Function Address for IOS_Open
Y values = Function Address for IOS_Ioctvl
Z values = Function Address for IOS_Close

Region-Free
00000FA0 00000020
00000FC0 00000000
02000FE0 00000000
02001000 00000000
02001020 00000300
00001040 00000000
04001060 030C0000
060009B0 00000048
XXXXXXXX YYYYYYYY
ZZZZZZZZ 00000000
80000FA0 00000001
80000FC0 00000001
80000FE0 00000002
80001000 00000002
80001020 00000002
80001040 00000001
80001060 00000003
C0000000 00000012
7D8802A6 9421FF80
BC610008 3FE08000
4800001D 2F646576
2F757362 2F6F6831
2F353765 2F333035
00000000 7C6802A6
38800002 819F09B0
7D8803A6 4E800021
2C030000 41800038
7C7E1B78 38800000
38A00006 38C00001
3CE08000 60E709C0
819F09B4 7D8803A6
4E800021 7FC3F378
819F09B8 7D8803A6
4E800021 B8610008
38210080 7D8803A6
4E800020 00000000

#MKW PAL IOS FUNCTIONS!

IOS_Open, 0x801938F8
IOS_Ioctlv, 0x801945E0
IOS_Close, 0x80193AD8


---
#C0

.macro push_stack
    mflr r12
    stwu sp, -0x80 (sp)
    stmw r3, 0x8 (sp)
.endm

.macro pop_stack
    lmw r3, 0x8 (sp)
    addi sp, sp, 0x80
    mtlr r12
.endm

push_stack

lis r31, 0x8000 #For loading shit

bl the_string

.string "/dev/usb/oh1/57e/305"
.align 2

the_string:
mflr r3
li r4, 2

#IOS Open
lwz r12, 0x09B0 (r31)
mtlr r12
blrl

cmpwi r3, 0
blt- _error

mr r30, r3
li r4, 0
li r5, 6
li 6, 1

lis r7, 0x8000
ori r7, r7, 0x09C0

#IOS_Ioctvl
lwz r12, 0x09B4 (r31)
mtlr r12
blrl

#No return value check? Ok.

mr r3, r30

#IOS_Close
lwz r12, 0x09B8 (r31)
mtlr r12
blrl

_error:
pop_stack

I want to know this, since I made a concept for a gliding code, which is attached to the message.