Xbox 360 save editing?

[Viper187]

So give us the dirt on how you found the checksum, did you just follow the video? Oh and in case you want to use the 360 DVD Drive (any of them but avoid the slims) on a PC with USB then you need:

http://www.x360usb.com/

I have the older version but works like a champ and also allows you to flash your firmware

Yeah, I'm thinking about getting one of those. The DVD drives have standard power connectors, right? I never took an Xbox apart. lol

Anyway, I the video example was enough for me. In the case of Rumble Roses, the checksum is the last few bytes of the file. There's no MC02 or the like that stands out as a header, but I finally noticed the first 4 bytes of the file was the size of the file and searched for that in IDA. One of the results turned up a sub that was obviously the checksum. The checksum itself is just loading every byte, sign extending, and adding. I about shit myself when I got it to run and turn up the right value the first time. lol

I'll paste the PowerPC for the checksum below, just for reference. I have two other titles at the top of my list for modding (Juiced 2 and Smackdown 2011). After that, I'll have to figure out what other games I have that need edited and don't have editors/checksum fixes. I'm sure I have a shitload.

.text:820F4080 sub_820F4080:                           # CODE XREF: .text:820F499Cp
.text:820F4080                                         # .text:820F49FCp
.text:820F4080                 lis       r10, 2 # 0x2AA3C # Load Immediate Shifted
.text:820F4084                 li        r9, 0         # Load Immediate
.text:820F4088                 addi      r11, r3, 3    # Add Immediate
.text:820F408C                 ori       r10, r10, 0xAA3C # 0x2AA3C # OR Immediate
.text:820F4090
.text:820F4090 loc_820F4090:                           # CODE XREF: sub_820F4080+58j
.text:820F4090                 lbz       r7, -2(r11)   # Load Byte and Zero
.text:820F4094                 addi      r10, r10, -1  # Add Immediate
.text:820F4098                 lbz       r8, -3(r11)   # Load Byte and Zero
.text:820F409C                 lbz       r5, -1(r11)   # Load Byte and Zero
.text:820F40A0                 extsb     r6, r7        # Extend Sign Byte
.text:820F40A4                 extsb     r8, r8        # Extend Sign Byte
.text:820F40A8                 lbz       r4, 1(r11)    # Load Byte and Zero
.text:820F40AC                 extsb     r7, r5        # Extend Sign Byte
.text:820F40B0                 lbz       r3, 0(r11)    # Load Byte and Zero
.text:820F40B4                 add       r8, r8, r6    # Add
.text:820F40B8                 extsb     r6, r4        # Extend Sign Byte
.text:820F40BC                 add       r8, r8, r7    # Add
.text:820F40C0                 extsb     r7, r3        # Extend Sign Byte
.text:820F40C4                 add       r8, r8, r6    # Add
.text:820F40C8                 addi      r11, r11, 5   # Add Immediate
.text:820F40CC                 add       r8, r8, r7    # Add
.text:820F40D0                 cmplwi    cr6, r10, 0   # Compare Logical Word Immediate
.text:820F40D4                 add       r9, r8, r9    # Add
.text:820F40D8                 bne       cr6, loc_820F4090 # Branch if not equal
.text:820F40DC                 mr        r3, r9        # Move Register
.text:820F40E0                 blr                     # Branch unconditionally

[Viper187]

I knew that was too easy. I can't find shit in the xex for Juiced 2. That game has been a thorn in my side for years now because it takes 6 people to finish some of the fucking career races to get 100%. An easy hex edit, if I could crack the fucking checksum.

[Viper187]

Well, big props to Philymaster as 360haven. He figured out the checksum for Juiced 2 and I put a tool together for it. I don't know how he did it though.