FF8 Checksum problem - Old title: Changing game time of FF8 PSX

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Hi, I want to change the game time of FF8 for PSX.
I don't have Visual C++ 2006 but I downloaded Griever's source code and I wrote a program in C++ trying to change the game time.
It doesn't work. Here I post the source code of my program.
Can anyone tell me what it's wrong?
Thank you and a happy new year to all users.

This is my code:
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Code:
#include <cstdlib>#include <iostream>#include <fstream>//Types of data used in this program. I use Dev C++, and so I don't know if BYTE, USHORT, etc. that I defined here//are the same types of Visual C++ 2006.typedef char BYTE;typedef unsigned short int USHORT;typedef unsigned int UINT;/////////////////////////////////////////////////////////////////// Final Fantasy VIII codes/*This, untill the main program, is the structure of one FF8 save blockthat I've found on Griever's source code.*//*enum FF8CHARID { Squall, Zell, Irvine, Quistis, Rinoa, Selphie, Seifer, Edea, Laguna, _zz1, _zz2, _blank, Griever, MiniMog, Chicobo, Angelo, None = 0xFF};*/#define CHAR_SQUALL        0#define CHAR_ZELL          1#define CHAR_IRVINE        2#define CHAR_QUISTIS       3#define CHAR_RINOA         4#define CHAR_SELPHIE       5#define CHAR_SEIFER        6#define CHAR_EDEA          7#define CHAR_LAGUNA        8#define CHAR_KIROS         9#define CHAR_WARD          10#define CHAR_GRIEVER       12#define CHAR_MINIMOG       13#define CHAR_CHICOBO       14#define CHAR_ANGELO        15#define CHAR_NONE          0xFFtypedef BYTE FF8CHARID;struct _FF8ITEM { BYTE type; char *name;};struct _FF8ABILITY { BYTE type; BYTE ap; char *name;};struct _FF8MAGIC { char *name;};#define CARD(t,l,r,b) { 0x##t,0x##l,0x##r,0x##b }#define NONE  -1#define FIRE  0#define ICE   1#define THUNDER  2#define EARTH  3#define POISON  4#define WIND  5#define WATER  6#define HOLY  7#define SIMPLE  0#define BOSS  1#define GF   2#define PLAYER  3struct _FF8CARD { char *name; struct _FF8CARDVALUES {  char top;  char left;  char right;  char bottom; } values; char element; char border;};struct _FF8CARDLOCATION { char *name;};struct _FF8LOCATION { char *name;};typedef BYTE _FF8INNATEABILITY;/////////////////////////////////////////////////////////////////// Final Fantasy VIII save file structures// Unknown datastruct UNKNOWN { UNKNOWN () { data = 0xFF; } BYTE data;};// FF8 text identifiertypedef char FF8STR;// Save file description blockstruct FF8DESC { USHORT checktag;   // Tag - must be 0x0FF8 USHORT location;   // Current location UNKNOWN zz0[4]; USHORT saves;    // Number of saves UINT gil;     // Gil UINT seconds;    // Game time BYTE level;     // Lead character's level FF8CHARID party[3];   // [3] Current party};// Guardian Force blockstruct FF8GF { FF8STR name[10];   // [10] GF name UNKNOWN zz1[2]; UINT exp;     // GF EXP UNKNOWN zz2; BYTE found;     // Has GF been found? USHORT hp;     // Current HP BYTE abilities[16];   // [16] Learned abilities (bLearned[i] = abilities[i/8] & (1 << (i%8))) BYTE ap[21];    // [21] Ability APs UNKNOWN zz3[3]; USHORT kills;    // Number of enemies killed USHORT ko;     // Number of KOs BYTE learning;    // Ability being learnt BYTE forgotten[3];   // Abilities forgotten};// Magic blockstruct FF8MAGIC { BYTE type; BYTE amount;};// Character blockstruct FF8CHAR { USHORT hp;     // Current HP USHORT basehp;    // Base HP UINT exp;     // EXP FF8CHARID id;    // Character id BYTE weapon;    // Current weapon BYTE str;     // Strength BYTE vit;     // Vitality BYTE mag;     // Magic BYTE spr;     // Spr BYTE spd;     // Speed BYTE luck;     // Luck FF8MAGIC magic[32];   // [32] Magic library (stock) BYTE ab_command[3];   // [3] Command abilities UNKNOWN zz; BYTE ab_char[4];   // [4] Character abilities USHORT gf;     // Junctioned GFs UNKNOWN zz2[2]; BYTE junction[19];   // [19] Junctions        // 00: HP Junction (Magic Type)        // 01: Str Junction (Magic Type)        // 02: Vit Junction (Magic Type)        // 03: Mag Junction (Magic Type)        // 04: Spr Junction (Magic Type)        // 05: Spd Junction (Magic Type)        // 06: Hit Junction (Magic Type)        // 07: Eva Junction (Magic Type)        // 08: Luck Junction (Magic Type)        // 09: Elem-Atk Junction (Magic Type)        // 10: ST-Atk Junction (Magic Type)        // 11: Elem-Def Junction 1 (Magic Type)        // 12: Elem-Def Junction 2 (Magic Type)        // 13: Elem-Def Junction 3 (Magic Type)        // 14: Elem-Def Junction 4 (Magic Type)        // 15: ST-Def Junction 1 (Magic Type)        // 16: ST-Def Junction 2 (Magic Type)        // 17: ST-Def Junction 3 (Magic Type)        // 18: ST-Def Junction 4 (Magic Type) UNKNOWN zz3; USHORT compat[16];   // [16] GF compatibility USHORT kills;    // Number of enemies killed USHORT ko;     // Number of KOs BYTE stats;     // Can view stats? UNKNOWN zz4; BYTE status;    // Status effects        //   1: ????        //   2: Poison        //   4: Petrify        //   8: Darkness        //  16: Silence        //  32: Berserk        //  64: Zombie        // 128: ???? UNKNOWN zz5;};// Item blockstruct FF8ITEM { BYTE type; BYTE amount;};// Card identifiertypedef BYTE FF8CARD;   // 0x80: Collected    0x7F: Amount        // Rare cards: Locationstruct FF8CONFIG { BYTE spd_battle;   // Battle speed (0=fast,4=slow) BYTE spd_battlemsg;   // Battle message speed (0=fast,4=slow) BYTE spd_fieldmsg;   // Field message speed (0=fast,4=slow) BYTE soundvolume;   // Sound volume (0-100(%)) BYTE options;    // Misc. options        //   1: ATB -   1:Wait  0:Active        //   2: ???        //   4: Cursor -  1:Memory 0:Initial        //   8: ???        //  16: ???        //  32: Controller - 1:Customize 0:Normal        //  64: ???        // 128: ??? BYTE scan;     //   1: Scan -   1:Always 0:Once BYTE camera;    // Camera movement (0=100%,4=0%) UNKNOWN zz1; UNKNOWN buttons[12];  // [12] Button configuration (?)};// Chocobo World datastruct FF8CHOCOBO { UNKNOWN zz[64];};// Save file blockstruct FF8BLOCK { UNKNOWN zz1[384]; USHORT checksum1;   // Checksum FF8DESC desc;    // Save block description FF8STR squall[12];   // [12] Squall's name FF8STR rinoa[12];   // [12] Rinoa's name FF8STR angelo[8];   // [8] Angelo's name UNKNOWN zz0[4]; FF8STR chicobo[4];   // [4] Chicobo's name UNKNOWN zz01[8]; BYTE disc;     // Current disc (zero based) UNKNOWN zz[3]; UINT saves;     // Number of times saved (*2?) FF8GF gf[16];    // [16] GF blocks FF8CHAR chars[8];   // [8] Character blocks UNKNOWN zz2[400]; FF8CONFIG config;   // Configuration FF8CHARID party[3];   // [3] Party UNKNOWN zz22[5]; FF8STR griever[8];   // [8] Griever's name UNKNOWN zz23[8]; UINT gil;     // Gil UNKNOWN zz24[4]; BYTE limits[6];    // [6] Learned limit breaks        // [0]-[1] Quistis        // [2]-[3] Zell        // [4] Irvine        // [5] Selphie BYTE combine_compl;   // Rinoa's Combine: Angelo Abilities Completed BYTE combine_known;   // Rinoa's Combine: Angelo Abilities Known BYTE combine_left[8];  // [8] Rinoa's Combine: Points left to learn different abilities        // [0] 'Angelo Rush'  (max 10)        // [1] 'Angelo Recover'  (max 30)        // [2] 'Angelo Reverse'  (max 40)        // [3] 'Angelo Search'  (max 60)        // [4] 'Angelo Cannon'  (max 80)        // [5] 'Angelo Strike'  (max 120)        // [6] 'Invincible Moon' (max 140)        // [7] 'Wishing Star'  (max 160) BYTE b_items[32];   // [32] Order of battle items FF8ITEM items[198];   // [198] Items//############################################################################################# UINT seconds;    // Game time (I want to change this)//############################################################################################# UNKNOWN zz28[8]; UINT battleswon;   // Number of battles won UNKNOWN zz29[2]; USHORT battlesescaped;  // Number of battles escaped UNKNOWN zz30[60]; BYTE limit_options;   // Limit break options (1:Renzokuken Auto, 2:Duel Auto) BYTE limit_indicator;  // Renzokuken indicator (128) BYTE dreamworld;   // Party isolated / Dream world (1) BYTE information[9];  // [9] Information (bitmask)        // [0]1-8: Location information        // [2]1-8: Location information        // [3]1-4: Location information        // [3]5-8: Term information        // [4]1-8: Term information        // [5]1-6: Term information        // [5]7-8: People information        // [6]1-5: People information        // [6]6-8: Character reports        // [7]1-4: Character reports        // [8]3-3: Term information        // [8]4-6: Report information UNKNOWN zz31; BYTE gf_reports[3];   // [3] GF reports UNKNOWN zz3[3]; BYTE testlevel;    // Current written test level UNKNOWN zz39[4]; FF8CHARID party_field[3]; // [3] Current field party ([0] = leader) UNKNOWN zz395[7]; USHORT location;   // Current location USHORT location_last;  // Last location (?) UNKNOWN zz4[30]; UINT steps;     // Number of steps taken USHORT payslip;    // Payslip steps UNKNOWN zz5[6]; USHORT seedlevel;   // SeeD Level UNKNOWN zz55[66]; UNKNOWN zz550[2];// USHORT location_last;  // Last location ? UNKNOWN zz551[186];  BYTE tt_rules[8];   // [8] Region game rules BYTE tt_traderules[8];  // [8] Region trade rules BYTE tt_lastrules[2];  // [2] Last game rules remembered ([1] = second to last) BYTE tt_lastregion[2];  // [2] Last region remembered ([1] = second to last) UNKNOWN zz555; BYTE tt_currules;   // Current game rule BYTE tt_curtraderule;  // Current trade rules BYTE tt_cardqueen;   // Card Queen's location BYTE tt_traderating_region; // Region for trade rating BYTE tt_traderating;  // Trade rating UNKNOWN zz6[1110]; FF8CARD cards[77];   // [77] Cards (bit 8=collected, bit 1-7=amount) BYTE card_locations[33]; // [33] Card locations BYTE cards_rare[5];   // [5] Rare cards found (bFound[i] = cardsfound[i/8] & (1 << (i%8))) UNKNOWN zz7[9]; USHORT test1; USHORT test2; FF8CHOCOBO cw;    // Chocobo World data USHORT checksum2;   // Checksum (identical to checksum1) BYTE padding[2782];   // Padding, makes save block 8192 bytes};///////////////////////////////////////////////////////////////////                      Main Program//////////////////////////////////////////////////////////////////*This is my code.The problem is that the game seconds are not right, so the data read from the memory card is not saved correctlyin the FF8BLOCK structure.And the size of my block is 8196 instead of 8192, and I don't know why.*/using namespace std;int main(int argc, char *argv[]){char FileName[100]; USHORT blocco; FF8BLOCK ff8; fstream FileMem; while(1) {//START of Whilecout<<"Size of my block: "<<sizeof(ff8)<<".\n";strcpy(FileName,"");cout << "Name of the memory card:\n";cin >> FileName;FileMem.open(FileName,ios::binary | ios::in | ios::out);if(!FileMem) cout<<"Impossible to open the file.\n\n";else{cout << "File loaded.\nInsert number of the block:\n";cin >> blocco;blocco-=1; //because I think that the block start from zerocout <<endl<<endl;int m_Type = 1; //I have a Memory Card File of 131'072 Byte, so the m_Type is 1 and theOffSet is zero.int offset;if(m_Type==1) offset = 0; //this is my caseif(m_Type==2) offset = 0xF40;if(m_Type==3) offset = 64;//8192 is 0x2000//now I do the same things that Griever do to read from the Memory Card:FileMem.seekg(offset+8192+(8192*blocco), ios::beg);FileMem.read((char*)&ff8, 8192);cout<<"Game time: "<<ff8.seconds<<";\n"; //but they are not rightff8.seconds = 20000; //sample value//and now I write on file. The writing seems to be correct, but the modify is not correct.//So the second doesn't change.FileMem.seekp(offset+8192+(8192*blocco), ios::beg);FileMem.write((char*)&ff8, 8192);cout<<"Game time modified.\n\n\n";FileMem.close();} }//FINE While return EXIT_SUCCESS; //end of Windows Application}
 
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Specifically what time are you trying to change (as I remember there were multiple) and what problems or errors did you encounter?

I was playing through the game to figure out all the bit fields in it but being a bit ADD I got distracted, however I have complete source of my plugin for modifying the data all you need is a program that can run the DLL's. I thought I had placed those available publicly but it's been numerous years since then.

So Qhimm, I, or any number of people likely can help you if you are more specific. Help us help you :)

Cyb
 
What time:
I'm sorry but I think that the time is only one. I mean the game time, to be more precise the numbers that appear in the menu on the bottom-right, just over the guil.
In the source code, I have specified where the seconds that I want to modified are (in the FF8 Save Block structure).

The problem:
I explained the errors adding comments in the source code.
In particular, the seconds read aren't correct. This means that the structure have some errors, I think.
Or maybe I read from the memory card file in a wrong way.
If you build the code, you can see that the seconds shown with "cout" can't be the correct seconds of the game.

If there are any other incomprension or doubts, tell me without problem.
Thank you for the answer.
 
You may have modified a time correctly or not if you don't compute the CRC correctly it is all for naught because it won't load correctly (IE it won't load?)

Also you are incorrect in that there is 1 single time there are TWO seperate time values one is in a structure used with the card information displayed on the PS1 (it's read by the game for a 'quick value' but I don't believe it's used) another time is further into the game save structure and this is the actual time.  The second time is JUST after the items in the FF8 data.

As I said which do you want?

Cyb
 
/*
This is my code.
The problem is that the game seconds are not right, so the data read from the memory card is not saved correctly
in the FF8BLOCK structure.
And the size of my block is 8196 instead of 8192, and I don't know why.
*/
The incorrect size sounds like an aligment problem, set a 1-byte boundary for struct alignment in your project, or use pack pragma, ie:

Code: [Select]
Code:
#pragma pack(push, 1)struct NameofStruct { // Struct members goes here...}#pragma pack(pop)
 
Zande, thank you very much, the problem was this. Now the size is correct, and the seconds read are correct.

Now, my last problem.

I need to calculate checksum, but the Griever's code doesn't work, I think due to the difference between Visual C++ and C++.

The code is this:
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Code:
void CalculateChecksum(FF8BLOCK &ff8){   WORD checksum = 0; void *dataptr = (void*)&ff8.gf;    asm{push dataptr  push 00001350h  push 00000000h } __asm {  sub esp, 00000200h  mov ecx, 00000080h  xor eax, eax  push esi  push edi  lea edi, dword ptr [esp+08h]  xor esi, esi  repz stosd  mov eax, 0000FFFFh  lea edi, dword ptr [esp+08h]label2:  mov ecx, esi  mov edx, 00000008h  shl ecx, 08hlabel3:  test ch, 80h  je label4  add ecx, ecx  xor ecx, 00001021h  jmp label5label4:  shl ecx, 1label5:  dec edx  mov word ptr [edi], cx  jne label3  inc esi  add edi, 00000002h  cmp esi, 000000FFh  jb label2  mov edi, dword ptr [esp+0000020Ch]  test edi, edi  jle label7  mov esi, dword ptr [esp+00000210h]label6:  xor ecx, ecx  xor edx, edx  mov dl, byte ptr [esi]  mov cl, ah  and ecx, 000000FFh  xor ecx, edx  xor edx, edx  mov dh, al  mov ax, word ptr [esp+2*ecx+08h]  xor ax, dx  inc esi  dec edi  jne label6label7:  pop edi  pop esi  not eax  add esp, 00000200h } __asm {  add esp, 0000000Ch  mov checksum, ax } ff8->checksum1 = ff8->checksum2 = checksum;}
So, WORD doesn't exist in c++, so I have replaced it with USHORT (unsigned short int) that I defined before, but is not the same. I don't know what to do.
__asm doesn't exist, the command is simply "asm".
But I have the following errors:

In the line:
Code: [Select]
Code:
asm{
I got this error: expected `(' before '{' token

°__°
To insert assembler instruction in a C or C++ program, the code is:
asm{
//assembler instructions
}
So, what's wrong with my code?

P.S. = I use DevC++.
 
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***Sorry for this message, admin can delete it.
Read the following message.
 
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Dev C++ uses GCC not VC++
Yes, I know, but I thought that asm was the same.

I made this change:
 __asm("istruction");
instead of using asm{list of instructions};

but I got a list of many assembler errors.
I have to modify the assembler code...  :-o
Nah, too difficult for me.

If someone can do it.. :)
 
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Read the first reference I gave you. :)
That will definately get you started.

Cyb
 
This is an old topic but I never solved my problem.
Anyway, I found a solution.
I've put this line on the compiler:
-masm=intel
so it works following Intel rules.

So my code now is this:
Code: [Select]
Code:
void CalcoloChecksum(FF8BLOCK &ff8){USHORT checksum = 0; void *dataptr = (void*)&ff8.gf;asm("push dataptr\n"    "push 00001350\n" "push 00000000\n");asm("sub esp, 00000200\n" "mov ecx, 0x00000080\n" "xor eax, eax\n" "push esi\n" "push edi\n" "lea edi, dword ptr [esp+0x08]\n" "xor esi, esi\n" "repz stosd\n" "mov eax, 0x0000FFFF\n" "lea edi, dword ptr [esp+0x08]\n");label2:asm("mov ecx, esi\n" "mov edx, 0x00000008\n" "shl ecx, 0x08\n");label3:asm("test ch, 80\n" "je label4\n" "add ecx, ecx\n" "xor ecx, 00001021\n" "jmp label5\n");label4:asm("shl ecx, 1\n");label5:asm("dec edx\n" "mov word ptr [edi], cx\n" "jne label3\n" "inc esi\n" "add edi, 00000002\n" "cmp esi, 0x000000FF\n" "jb label2\n" "mov edi, dword ptr [esp+0000020Ch]\n" "test edi, edi\n" "jle label7\n" "mov esi, dword ptr [esp+00000210]\n");label6:asm("xor ecx, ecx\n" "xor edx, edx\n" "mov dl, byte ptr [esi]\n" "mov cl, ah\n" "and ecx, 0x000000FF\n" "xor ecx, edx\n" "xor edx, edx\n" "mov dh, al\n" "mov ax, word ptr [esp+2*ecx+0x08]\n" "xor ax, dx\n" "inc esi\n" "dec edi\n" "jne label6\n");label7:asm("pop edi\n" "pop esi\n" "not eax\n" "add esp, 00000200\n");asm("add esp, 0000000Ch\n" "mov checksum, ax\n"); ff8.checksum1 = ff8.checksum2 = checksum;}
But I got the followings errors:
Assembler messages:
  junk `Ch' after expression
  junk `Ch' after expression
Path_of_the_project\Makefile.win [Build Error]  [main.o] Error 1

Can anyone help me?
I don't know what's wrong.
 
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Just out of curiosity, I have to ask, why do you want to go to so much trouble just to change your game time?
Unless your truly terrible, and have a really lousy time, I can't really see a reason to go through so much for such an insignificant thing.
 
Eh, eh, a lot of people asked me this.
Do you know that when your timer reach 99:59 it turns into red and restart from 00:00? Well, I simply wanted to know what it does then. So, modifying the save, I have managed to see that when you reach 99 hours and 59 minutes red, the colour changes to blue, then to yellow, green, and purple. At 99:59 purple the timer stops. This corresponds to 600 hours of playing.
I simply wanted to know this, I was curious, I wanted to know all of FF8.

Now I've reached my goal, but I want to modify other things. To do this, I cannot satisfy myself seeing the blocks like I've done to knowing the game time behaviour, but I have to do CRC control.
So, now I need your help.
 
You solved or didn't solve the problem?

I'm confused. I have code that generates the CRC however I probably should reduce it to a standard CRC polynomial and SEED format to perform the calculation (in a normal manner).

Things you do when you are ... young  :roll:

I'll have to dig it up.  I haven't messed with FF8 data in ... 2 years :D

Cyb
 
It's possible but do you understand how the CRC function works even?

I think that you need to study it instead of someone else completely doing it for you.

Look up CRC calculation on the net first. There are some general routines available on the net for it.

The most common way to do the CRC is to have a table to look up the values and generate the CRC based on the table data.

The table is generated from each possible symbol to find the next CRC symbol.

The method used in Qhimm's griever code is similar to this, except it calculates the high and low byte tables together (ugh) each time the CRC routine is called and uses that table to compute the CRC of the data in the FF8 save. This makes the code a bit more cryptic to look at because it requires a lot of fancy byte swapping at the end.

The SEED value for the CRC is 0xFFFF and the POLYNOMIAL is 0x1021.  The save data block length is 0x1350 or 4944 bytes.

Everything in bold letters is a hint :D

Erstwhile I rewrote my Grieve DLL to use a table CRC instead thus it's a bit faster but mostly easier to understand.

Cyb
 
I wasn't interested to understand the CRC simply because I'm studying and programming other things and I only wanted to create a personal Griever quickly, with the purpose of changing stuffs that Qhimm's Griever doesn't.
Moreover, I have only two errors on my code now, so I wanted only a correction.

In any case thanks for the hints and the links.
 
What were your errors then?
The assembly code reads a bit strange but it does work by the way.

And if you have questions apart from Qhimm's reference material <TM> ask me I went further than he did with the save data.
Cyb
 
What were your errors then?
The assembly code reads a bit strange but it does work by the way.
I have a feeling that you don't read my posts entirely... :D
I show again this link: https://www.ff7catalog.com/posts/66284/
Or rather, I'll quote to you the part of the post that shows the errors:
But I got the followings errors:
Assembler messages:
  junk `Ch' after expression
  junk `Ch' after expression
Path_of_the_project\Makefile.win [Build Error]  [main.o] Error 1
I hope that the code will work correcting these errors.
 
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