Need help with GBA codetypes

[47iscool]

I've looked at some codes in the db but can't figure out the ROM patching technique.

The ROM address is 0x35A4

I can't figure out what codetype will patch 0000 to ROM address 0x35A4.
Can someone please explain to me how they work? DS codes are easy compared to this.

[lee4]

its should be like this for rom address

cb codetype
880035A4 0000

ar3 codetype
018035A4 00000000

[47iscool]

its should be like this for rom address

cb codetype
880035A4 0000

ar3 codetype
018035A4 00000000

Not working with VBA. I know this is the correct address because I patched the ROM with 0000 and it worked.

The game is Corvette and the code disables the countdown timer. I even entered the code as a CB code too, maybe VBA is problematic with these codetypes?

[Demonic722]

Use AR Crypt with code type z0C. If the address is 0x080035A4 and you're writing 0x0000 to it, you should get:

A329B888 3CBFBB1F
A05A144C 078B0074

VBA will take this as a Code Breaker code:

880035A4 0000

Edit: I just ran the game just to follow along.

080035A4 8510    strh r0,[r2,#0x28]

You're replacing this store with 0x0000 (lsl r0,r0,#0x0). If you were going for a NOP, in Thumb, 0x46C0 is the value. I think you're used to seeing 0x0000 as the value for it since that's how it is in MIPS.

[47iscool]

Use AR Crypt with code type z0C. If the address is 0x080035A4 and you're writing 0x0000 to it, you should get:

A329B888 3CBFBB1F
A05A144C 078B0074

VBA will take this as a Code Breaker code:

880035A4 0000

The first one works, thanks! I don't understand what you mean by z0C though, what does it mean? BTW
"880035A4 0000" doesn't work as a CB code, at least not in VBA.

GBA codetypes are more confusing than anything I've ever seen.

[Demonic722]

Open AR Crypt or visit the Enhacklopedia.

[47iscool]

Copied and pasted into a text file for further reference. Thanks D722. About the NOP value, I thought it was 0x00000000 because if I'm not mistaken that's the same NOP value the DS uses is it not? I thought the DS and GBA had similar CPU's. Thanks for the info.

[Demonic722]

The DS and GBA can both perform ARM (32-bit opcodes) and Thumb (16-bit opcodes) instructions. The value for NOP in ARM is 0xE1A00000; Thumb is 0x46C0. 0x00000000 in ARM, if I'm not mistaken, is the value for the instruction andeq r0,r0,r0. Which debugger are you using by the way?

[47iscool]

The DS and GBA can both perform ARM (32-bit opcodes) and Thumb (16-bit opcodes) instructions. The value for NOP in ARM is 0xE1A00000; Thumb is 0x46C0. 0x00000000 in ARM, if I'm not mistaken, is the value for the instruction andeq r0,r0,r0. Which debugger are you using by the way?

Uh, well I guess you could say Cheat Engine. I searched the value of the timer and the ESI address from the writes is 0x03000148, which I searched for the timer on VBA and it gave me the exact same address. The EDI it gave me was 0x000035A8 which is 4 addresses ahead of 0x35A4. It's more simple than I thought it would be, I could never get the hang of using the no$GBA debugger.

Like so:

Address of timer in CE's list: 0x02391F10
ESI address in CE's "find what writes to this address": 0x03000148> Which the actual address in the GBA RAM
EDI address in CE's "find what writes to this address": 0x000035A8>ASM that causes the write.

[Demonic722]

Ah, alright. I thought you were using MESS because I was going to recommend NO$GBA as an alternative since it displays the values of the instructions in the debugger.

[47iscool]

Ah, alright. I thought you were using MESS because I was going to recommend NO$GBA as an alternative since it displays the values of the instructions in the debugger.

Well I would say that it (CE+VBA) is faster when you need to find what's writing what where.

[47iscool]

Another question, what is the NOP value for the original GameBoy Mono? Is it "EA" like the NES?

[Demonic722]

Game Boy Mono? The Game Boy/Color? I know that it uses z80 and I think the value for it is 0x00.

[47iscool]

Game Boy Mono? The Game Boy/Color? I know that it uses z80 and I think the value for it is 0x00.

Thanks

I've heard the term mono thrown around for the original GameBoy, so that's what I've called for a while.

[lee4]

can someone convert these codes to codebreaker format?

I tried both online and offline converter, they would not convert properly,
please help.

Street Fighter Alpha 3 - GBA | AR3

Easier Super Combos[See Notes]
4699B64C D258B4C7
AD86124F 2823D8DA

Easier Raging Demon[See Notes]
4699B64C D258B4C7
AD86124F 2823D8DA
731A5435 479DECE8
924AC84E 6409D6B3

source:
http://gamehacking.org/vb/threads/44...0360#post70360