Topic: FBA port of Nicola's CPS2 decryption code

[Leaf]

I found it when iq_132 post the file ported from MAME, but I'm not sure.
(http://neo-source.com/index.php?topic=590.0)

I noticed that it exists in FBA Alpha 0.2.96.65 too.

static void cps2_decrypt(const UINT32 *master_key, unsigned int upper_limit)
{
        ......

#if 1
   UINT16 *rom = (UINT16 *)CpsRom;
   unsigned int length = upper_limit;
   CpsCode = (UINT8*)malloc(length);  <== allocated but not free
   UINT16 *dec = (UINT16*)CpsCode;
   unsigned int i;
#endif
       ......

Here I made a simple fix.
For CPS2 is fully decrypted now, we don't need the loading xor code.
In cps.cpp, find these in CpsGetROMs()

Code: [Select]

    unsigned char* CpsCodeLoad = CpsCode;
    .....
    if (!CpsCodeLoad || !CpsRomLoad || !CpsGfxLoad || !CpsZRomLoad || !CpsQSamLoad) {
return 1;
    }
    ....
    // XOR tables
    if ((ri.nType & 7) == 2) {
if (bLoad) {
BurnLoadRom(CpsCodeLoad, i, 1);
CpsCodeLoad += ri.nLen;
} else {
nCpsCodeLen += ri.nLen;
}
continue;
   }
comment them or delete CpsCodeLoad.

in CpsInit(), add this at first:

Code: [Select]

    unsigned char* CpsCodeIn = NULL;

then find:

Code: [Select]

CpsCode = CpsRom + nCpsRomLen;
if (Cps1Qs == 1) {
CpsEncZRom = CpsCode + nCpsCodeLen;
CpsZRom = CpsEncZRom + nCpsZRomLen * 2;
} else {
CpsZRom = CpsCode + nCpsCodeLen;
}
replace it with:

Code: [Select]

CpsCodeIn = CpsRom + nCpsRomLen;
if (Cps1Qs == 1) {
CpsEncZRom = CpsCodeIn + nCpsCodeLen;
CpsZRom = CpsEncZRom + nCpsZRomLen * 2;
} else {
CpsZRom = CpsCodeIn + nCpsCodeLen;
}

in CpsExit(), add

Code: [Select]

free(CpsCode);
before

Code: [Select]

nCpsCodeLen = nCpsRomLen = nCpsGfxLen = nCpsZRomLen = nCpsQSamLen = nCpsAdLen = 0;

If you want to keep the loading xor code, maybe you should define a new pointer used to point the new allocated memory
in cps2_decrypt() and don't forget to free it in CpsExit().
 

[CaptainCPS]

ThanX Leaf! added the fix to the actual FBA Extras so it should be included in R10 version 

SeeYaa!
 

[iq_132]

Hadn't noticed this, nice find Leaf. ^^