Wii Asm hacking Mips help

[nolberto82]

Makes sense I suppose, so what about making more advanced asm codes, like helder made a no charge asm code for a street fighter game, so that it works for all fighters the question is how did he know what address and instruction to find in the debugger, in order to make the code?

Also say I wanted to explore where more data relating to a code is in the debugger take a character modifier code as an example, is all the addresses surrounding the actual character modifier instruction in the debugger, useless or could I still find new addresses in the debugger relating to an aspect of the character modifier, can I find new codes in asm by backtracking existing ram codes in the debugger?

You're asking about making advanced codes but can you make simple ones? PowerPC is not an easy CPU to experiment I'll go with something easier. Helder knew what opcode to change in that game because he is familiar with the game's CPU instructions. You don't change CPU instructions at random and you've to know what the disassembler is telling you before you even think about backtracing or you'll get lost. It takes practice and time to become good ASM hacker.

[Helder]

Like everyone said and myself included in the other thread, do hands on experimenting and try to read what the instructions are doing. When you get a break it's either doing some kind of writing or loading so it's always best to start from a load instruction and go line by line seeing what is being performed and what is also in the registers which is very important.

[jin299]

So When backtracking through a code in the debugger, what would the best way be to locate the information your looking for.

Example I want to explore, the other possibilities relating to a character in a game so what I'm planning on doing is setting a breakpoint on the character modifier address, and then try and find some more information relating to the character example there music, there voice ect in the debugger by backtracking, the only problem is I can locate the correct instruction in the debugger that loads what character is chosen in the game, simply by looking at the registers in the debugger but I don't understand what the other addresses surrounding the character modifier address do, where should I start when backtracking through the other addresses in the debugger?

[Helder]

Once you find the pointer that loads that specific character's data in the registers go to that location of that pointer and just poke around changing things a bit 1 by one till you see what changed or observe the data in realtime and see what changes when you change characters to try to understand what is what.

[olala]

e.g., the character data is 80 bytes in size, and bytes 24-27 are the experience

Think of RAM as a scratchpad

You don't change CPU instructions at random

just poke around changing things a bit 1 by one

all noted on mine sticky note already
thancou
dood

[jin299]

Right and Helder would it be safe to check the registers surrounding the character modifier code, as well I suspect these are the registers I should be looking closely at while the game is running in realtime. Right?

Also when would the best time be to see if any changes have taken place in the game, when modifying an instruction in the debugger, I was thinking first I must observe the registers as I'm picking a character in real time.