1. ASM Patch Templates and associated programs
   Allows you to change or create custom code for the game. The most updated templates are included with the latest SM64DSe, but you will still need the associated programs in the above link. The header files and symbols.x included with the templates contain a lot of useful memory addresses and offsets for researching and writing your own code (there are 2 "versions" of the template docs - v2 by mibts has a lot more features, but v1 also has some helpful stuff and is probably more beginner-friendly).


2. Modified version of NSMBe
   Optional - allows you to directly overwrite existing code rather than jumping to new code (useful for changing data tables and pointers).


3. no$gba debugger
   Allows you to change and test code live in-game, or to set breakpoints and conduct your own research. Make sure you get the debug version.

• When writing hooks with the ASM Patch Template, you need to specify the overlayID in hexadecimal (whereas the overlay numbers documented below are in decimal).
  Eg, to use the 'nsub' hook for something located in overlay 98 (0x62) you would write "nsub_02xxxxxx_ov_62".


• In ARM ASM, ldrb/strb means load/store byte (1 byte), and ldrh/strh means load/store halfword (2 bytes). Default is 4 bytes, without the b/h suffix.


• In no$gba, you can change data values by going to the memory location and changing the instruction to "dcd 0xXXXXXXXX" (where the X's are the data you want).
  Don't use "dcd" when compiling code for the ASM Patch Templates though - use ".word", ".hword", or ".byte" instead.
  

Yoshi: can punch and grab

Hold "Y" (sprint) while attacking to punch/grab/dive: this post


Player: speed and jump height

See this post


Wing Cap: who can get Feather powerup

There are several parts to this:

1. When a Feather exists, the game constantly checks whether the player is Mario and immediately despawns the Feather if not (eg, if player loses their Mario disguise)
2. When the Feather is collected, the game again checks if the player is Mario (if not, the Feather disappears without giving any powerup)
3. To spawn a Feather, you can either use the "! Block VS" object or change who "? Blocks" give Feathers to (for "? Blocks" that normally only give Feathers to Mario).

Despawn loop check: here
Whether to give wings when collected: here
Whether relevant "? Blocks" spawn Feathers or Power Flowers: here


Power Flowers: who can see Power Flowers in mirror room

Unfortunately crashes when collected by Mario/Wario in Castle 2F, and there is no reflection for Yoshi's fire breath. But it seems to work properly in painting levels. Including this in case anyone wants to use static Power Flowers in custom/painting levels only.

Visibility of static Power Flowers: here


Brick Blocks / Black Brick Blocks: who can break

When ground pounded: here
When kicked or sweep kicked: here
When punched: here
On explosion: here


Ice Blocks: can be shattered

See this post


Boos: who can defeat

On any attack that can normally defeat Boos: here


Bob-ombs: whether to reappear and what to spawn when defeated

Whether to reappear: here
What to spawn: here


Piranha Plants: whether to reappear and what to spawn

When defeated: here


Wooden Crates: whether to reappear and what to spawn

When broken: here
When swallowed by Yoshi: here


Yellow Coins / Blue Coins: whether they disappear

Countdown timer: here


Object Draw Distances

Easy way to change for all or specific objects: here

Something easy: you could set a fixed draw distance for everything (r2 = 0x600000 seems to give good results without killing the frame rate)
Something fancy: offset 0xC (2 bytes) of the object's address (r4) is the ActorID of the object - so you could check this to set different draw distances for different objects


Bowser Star Doors / Endless Stairs: star and character requirements

Bowser Star Doors: here
Endless Stairs - music/lighting effects: here
Endless Stairs - whether can get to top: here

Change when you get "recovered X stars" messages: here


Power Stars: whether to continue or exit level after collecting

100-Coin Stars: here
Level type: here


Level and level transition behaviours

See this post

Allows you to do things like:

• create mega levels with more than 8 Power Stars
• set the StarID for castle/boss maps - so these can have different configurations after an event of your choosing has occured
• 100-coin stars in secret/boss levels
  

1. Finding a suitable starting breakpoint, eg Actor::Spawn() function (which is called any time something is spawned, such as a coin).

The ASM Hacking Templates (especially symbols.x and SM64DS_2.h from v2) are fantastic resources of currently known data locations, subroutines and their memory addresses. Action Replay codes can also be very helpful, if there is one that does something similar to what you want. Lastly, you can find addresses of object-specific callbacks (eg, OnGroundPounded(), OnKicked(), etc) by following steps 1-8 of Fiachra's tutorial for finding an object's constructor - after the constructor address, you'll see a long list of more addresses (which are the addresses of the various callback functions).


2. Either tracing backwards through from the breakpoint to figure out where and how the game determines whether to go to that piece of code, or tracing forwards from the breakpoint to find when the game checks for something (eg, type of character).

You'll need some ASM knowledge and a bit of creativity/patience. Tracing backwards involves looking at r14 (LR) to find earlier code that called your breakpointed code (and repeat if necessary). Unfortunately sometimes code uses "b" jumps rather than "bl" jumps (which don't store the return address to r14), so you might end up further back then you wanted and then have to step forwards. For tracing forwards, you can use "F7" in no$gba to step through code line by line (the debugger helpfully tells you the value of registers and whether conditional instructions evaluate to 'true' or 'false' as you step through). You can also use no$gba to change code on the fly to see if it changes what you want to change. Chaining breakpoints and conditional breakpoints can be very helpful (see this post for an example).

Yoshi: can punch and grab

How the game decides whether to perform a 'punch' or 'eat' attack: here

Here's a quick patch for ASMPatchTemplate which allows Yoshi to use both his new and old attacks (hold "Y" while attacking to punch/dive/grab, etc):


YoshiCanPunchAndEat.s


nsub_020DDEAC_ov_02:

@ check if character is Yoshi
ldr r0, [r4, #0x8]
cmp r0, #0x3
bne 0x020DDEDC

@ approach used by the game to get "INPUT_PERSISTENT"
ldr r1, =0x020A0E40
mov r0, #0x18
ldrb r2, [r1]
ldr r1, =0x0209F49C
mul r0, r2, r0
ldrh r0, [r1, r0]

@ choose attack depending on whether "Y" is pressed
ands r0, r0, #0x800
beq 0x020DDEB8
b 0x020DDEDC

To switch to hold "Y" for eat attack, just change the "beq" to "bne" (but the current setup feels more natural for dive attacks while sprinting).

1. Whether a Power Star sends you back to the castle or lets you continue
2. Whether or not the course star select / load screen is displayed
3. Which StarID to enter the level as, without the star select screen
4. Which type of pause screen and congratulations text used for different levels

Posted by StarPants

Nice! How did you discover Yoshi's secret abilities in the first place?

1. I set a read breakpoint on INPUT_1_FRAME to see when the game checks for "A" keypress (note that Yoshi doesn't keep sticking his tongue out if you hold "A" so guessed it was checking INPUT_1_FRAME rather than INPUT_PERSISTENT)
2. Got the value to look for through DeSmuME RAM watch, then cycled through the breakpoints until I found it check for the "A" key (luckily there weren't many and didn't have to look very hard)
3. While still breakpointed at the "A" key check, I set a read breakpoint for the acting character type (Player object address + 0x8) to see when ths game next checks who you are playing as

Power Stars: whether to continue or exit level after collecting

100-Coin Stars: here
Level type: here


Level: whether to display star select screen

Level type, moving between levels: here
See below on how to set the star number without the star select screen


Level: set star number for level

See here
Allows you to create multiple setups for the secret/boss/castle levels, or force the star number if you don't want courses to have star select screens


Level: persistence across levels

Coin count and object respawns: here
Note: some objects are not added to the death table, so will respawn when moving between sublevels (eg, Brick Blocks in Cool Cool Mountain after you return from the slide)


Level: attainability of 100-Coin Stars

Level type and coin requirements: here
(Thanks to whoever created the Action Replay code for the offset)


Whether and when to display "recovered X stars" text

See here


Pause Menu: whether can "Exit Course"

See here


Pause Menu: make Main Castle use course/level pause screen

Change the instruction at each of the following addresses from cmp r0, 0x1D" (castle ActID) to "cmp r0, 0xFE" (or another unused ActID):


0x0202DC74 - loads background for course/level pause screen (when entering castle level)
0x02029550 - shows text for course/level pause screen
0x020252B4 - don't show star map on top screen
0x020280C8 - fix glitch when entering Options screen
0x02028B74 - fix glitch when leaving Options screen
0x02027FD4 - fix glitch when leaving Controller Modes screen



Pause Menu / Star Text: make main courses like secret/boss levels

To make pause menu only show the course name (like with secret/boss levels), and make the text when you leave with a Power Star like that for secret or boss levels:


0x0201D860:
- set r6 to either 0x12 or 0x15 instead (same effect for pause menu, for exit text 0x12 = "[course name] COMPLETE" and 0x15 = "another castle secret star CLEAR")
- store r0 (the level's real ActID) to a global variable

0x0201DA6C:
- get the stored (real) ActID and add to r0 instead (this makes it display the correct course name)
- leave the value of r6 untouched (ie, still 0x12 or 0x15)

0x02025680:
- make the jump unconditional (removes "score" from pause screen)

0x02023E54:
- conditional branch - if true, displays "Congratulations" bubble text on exit (like after boss fight)

0x02024568:
- jump to 0x0202457C (saves highscore but doesn't display "Highscore" bubble text)

Ice Blocks: breakability when attacked

To make them breakable: here
To change which characters can break them, see "Brick Blocks / Black Brick Blocks: who can break" in the first post

Posted by Hiccup

The reason the ice block breaking works with the shards may be because you technically can break them if you hack Giant Mario into the level and walk into one.

Player: move speed and acceleration

See here (including ceiling hang and slippery slide)

Despite what many game guides say, all characters have the exact same acceleration and deceleration (and no, Luigi does not have a faster top speed than Mario).
Also, thanks to Skelux's "Increase Acceleration" additional patch for the memory address re ground acceleration.


Player: carry speed

Regular and heavy objects: here


Player: swim speed

See here


Player: jump power

See here (including back flip, side flip and long jump)

Posted by StarPants

I saw there was something going on in the registers but couldn't analyse it any further. I'm glad you got it.

unrelatedly: If anyone's doing a kaizo they can try to nop at 0x020BF330. I tried in first person and it felt pretty much like a motorbike without breaks. Never rode one irl though.

ldr r2, [r0, 0x8] // r2 = 4 bytes at address (r0 + 0x8) = charID (0:M, 1:L, 2:W, 3:Y)
ldr r0, =0x020FF170 // r0 = 0x020FF170
and r2, r2, 0xFF // r2 = r2 bitwise AND 0xFF (seems unnecessary?)
mov r2, r2, lsl 0x1 // r2 *= r2 (left shift 1 bit is effectively x2) = charID x2
ldrh r2, [r0, r2] // r2 = 2 bytes at address (0x020FF170 + charID x2)