vbagx/source/vba/Patch.cpp
2008-10-27 05:02:06 +00:00

472 lines
9.7 KiB
C++

// VisualBoyAdvance - Nintendo Gameboy/GameboyAdvance (TM) emulator.
// Copyright (C) 1999-2003 Forgotten
// Copyright (C) 2004-2006 Forgotten and the VBA development team
// Copyright (C) 2007-2008 VBA-M development team and Shay Green
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or(at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation,
// Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <zlib.h>
#include "System.h"
#include "memfile.h"
/*
#ifdef __GNUC__
typedef off64_t __off64_t;
#endif
*/
#ifndef _MSC_VER
#define _stricmp strcasecmp
#endif // ! _MSC_VER
#ifdef _MSC_VER
#define fseeko64 _fseeki64
#define ftello64 _ftelli64
typedef __int64 __off64_t;
#endif
#if defined(__APPLE__) || defined (MACOSX)
#define fseeko64 fseeko
#define ftello64 ftello
typedef off_t __off64_t;
#endif /* __APPLE__ || MACOSX */
static int readInt2(MFILE *f) {
int res = 0;
int c = memfgetc(f);
if (c == MEOF)
return -1;
res = c;
c = memfgetc(f);
if (c == MEOF)
return -1;
return c + (res << 8);
}
static int readInt3(MFILE *f) {
int res = 0;
int c = memfgetc(f);
if (c == MEOF)
return -1;
res = c;
c = memfgetc(f);
if (c == MEOF)
return -1;
res = c + (res << 8);
c = memfgetc(f);
if (c == MEOF)
return -1;
return c + (res << 8);
}
static s64 readInt4(MFILE *f) {
s64 tmp, res = 0;
int c;
for (int i = 0; i < 4; i++) {
c = memfgetc(f);
if (c == MEOF)
return -1;
tmp = c;
res = res + (tmp << (i * 8));
}
return res;
}
static s64 readInt8(MFILE *f) {
s64 tmp, res = 0;
int c;
for (int i = 0; i < 8; i++) {
c = memfgetc(f);
if (c == MEOF)
return -1;
tmp = c;
res = res + (tmp << (i * 8));
}
return res;
}
static s64 readVarPtr(MFILE *f) {
s64 offset = 0, shift = 1;
for (;;) {
int c = memfgetc(f);
if (c == MEOF)
return 0;
offset += (c & 0x7F) * shift;
if (c & 0x80)
break;
shift <<= 7;
offset += shift;
}
return offset;
}
#ifndef MIN
#define MIN(a,b) (((a)<(b))?(a):(b))
#endif
static uLong computePatchCRC(MFILE *f, unsigned int size) {
Bytef buf[4096];
long readed;
uLong crc = crc32(0L, Z_NULL, 0);
do {
readed = memfread(buf, 1, MIN(size, sizeof(buf)), f);
crc = crc32(crc, buf, readed);
size -= readed;
} while (readed > 0);
return crc;
}
bool patchApplyIPS(MFILE * f, u8 **r, int *s) {
// from the IPS spec at http://zerosoft.zophar.net/ips.htm
bool result = false;
u8 *rom = *r;
int size = *s;
if (memfgetc(f) == 'P' && memfgetc(f) == 'A' && memfgetc(f) == 'T'
&& memfgetc(f) == 'C' && memfgetc(f) == 'H') {
int b;
int offset;
int len;
result = true;
for (;;) {
// read offset
offset = readInt3(f);
// if offset == MEOF, end of patch
if (offset == 0x454f46 || offset == -1)
break;
// read length
len = readInt2(f);
if (!len) {
// len == 0, RLE block
len = readInt2(f);
// byte to fill
int c = memfgetc(f);
if (c == -1)
break;
b = (u8) c;
} else
b = -1;
// check if we need to reallocate our ROM
if ((offset + len) >= size) {
#ifdef NGC
size = offset + len;
#else
size *= 2;
rom = (u8 *) realloc(rom, size);
#endif
*r = rom;
*s = size;
}
if (b == -1) {
// normal block, just read the data
if (memfread(&rom[offset], 1, len, f) != (size_t) len)
break;
} else {
// fill the region with the given byte
while (len--) {
rom[offset++] = b;
}
}
}
}
return result;
}
bool patchApplyUPS(MFILE * f, u8 **rom, int *size) {
s64 srcCRC, dstCRC, patchCRC;
memfseek(f, 0, MSEEK_END);
long int patchSize = memftell(f);
if (patchSize < 20) {
return false;
}
memfseek(f, 0, MSEEK_SET);
if (memfgetc(f) != 'U' || memfgetc(f) != 'P' || memfgetc(f) != 'S'
|| memfgetc(f) != '1') {
return false;
}
memfseek(f, -12, MSEEK_END);
srcCRC = readInt4(f);
dstCRC = readInt4(f);
patchCRC = readInt4(f);
if (srcCRC == -1 || dstCRC == -1 || patchCRC == -1) {
return false;
}
memfseek(f, 0, MSEEK_SET);
u32 crc = computePatchCRC(f, patchSize - 4);
if (crc != patchCRC) {
return false;
}
crc = crc32(0L, Z_NULL, 0);
crc = crc32(crc, *rom, *size);
memfseek(f, 4, MSEEK_SET);
s64 dataSize;
s64 srcSize = readVarPtr(f);
s64 dstSize = readVarPtr(f);
if (crc == srcCRC) {
dataSize = srcSize;
} else if (crc == dstCRC) {
dataSize = dstSize;
} else {
return false;
}
if (dataSize != *size) {
return false;
}
s64 relative = 0;
u8 *mem;
while (memftell(f) < patchSize - 12) {
relative += readVarPtr(f);
if (relative > dataSize)
continue;
mem = *rom + relative;
for (s64 i = relative; i < dataSize; i++) {
int x = memfgetc(f);
relative++;
if (!x)
break;
if (i < dataSize) {
*mem++ ^= x;
}
}
}
return true;
}
static int ppfVersion(MFILE *f) {
memfseek(f, 0, MSEEK_SET);
if (memfgetc(f) != 'P' || memfgetc(f) != 'P' || memfgetc(f) != 'F')
return 0;
switch (memfgetc(f)) {
case '1':
return 1;
case '2':
return 2;
case '3':
return 3;
default:
return 0;
}
}
int ppfFileIdLen(MFILE *f, int version) {
if (version == 2) {
memfseek(f, -8, MSEEK_END);
} else {
memfseek(f, -6, MSEEK_END);
}
if (memfgetc(f) != '.' || memfgetc(f) != 'D' || memfgetc(f) != 'I'
|| memfgetc(f) != 'Z')
return 0;
return (version == 2) ? readInt4(f) : readInt2(f);
}
static bool patchApplyPPF1(MFILE *f, u8 **rom, int *size) {
memfseek(f, 0, MSEEK_END);
int count = memftell(f);
if (count < 56)
return false;
count -= 56;
memfseek(f, 56, MSEEK_SET);
u8 *mem = *rom;
while (count > 0) {
int offset = readInt4(f);
if (offset == -1)
break;
int len = memfgetc(f);
if (len == MEOF)
break;
if (offset + len > *size)
break;
if (memfread(&mem[offset], 1, len, f) != (size_t) len)
break;
count -= 4 + 1 + len;
}
return (count == 0);
}
static bool patchApplyPPF2(MFILE *f, u8 **rom, int *size) {
memfseek(f, 0, MSEEK_END);
int count = memftell(f);
if (count < 56 + 4 + 1024)
return false;
count -= 56 + 4 + 1024;
memfseek(f, 56, MSEEK_SET);
int datalen = readInt4(f);
if (datalen != *size)
return false;
u8 *mem = *rom;
u8 block[1024];
memfread(&block, 1, 1024, f);
if (memcmp(&mem[0x9320], &block, 1024) != 0)
return false;
int idlen = ppfFileIdLen(f, 2);
if (idlen > 0)
count -= 16 + 16 + idlen;
memfseek(f, 56 + 4 + 1024, MSEEK_SET);
while (count > 0) {
int offset = readInt4(f);
if (offset == -1)
break;
int len = memfgetc(f);
if (len == MEOF)
break;
if (offset + len > *size)
break;
if (memfread(&mem[offset], 1, len, f) != (size_t) len)
break;
count -= 4 + 1 + len;
}
return (count == 0);
}
static bool patchApplyPPF3(MFILE *f, u8 **rom, int *size) {
memfseek(f, 0, MSEEK_END);
int count = memftell(f);
if (count < 56 + 4 + 1024)
return false;
count -= 56 + 4;
memfseek(f, 56, MSEEK_SET);
int imagetype = memfgetc(f);
int blockcheck = memfgetc(f);
int undo = memfgetc(f);
memfgetc(f);
u8 *mem = *rom;
if (blockcheck) {
u8 block[1024];
memfread(&block, 1, 1024, f);
if (memcmp(&mem[(imagetype == 0) ? 0x9320 : 0x80A0], &block, 1024) != 0)
return false;
count -= 1024;
}
int idlen = ppfFileIdLen(f, 2);
if (idlen > 0)
count -= 16 + 16 + idlen;
memfseek(f, 56 + 4 + (blockcheck ? 1024 : 0), MSEEK_SET);
while (count > 0) {
s64 offset = readInt8(f);
if (offset == -1)
break;
int len = memfgetc(f);
if (len == MEOF)
break;
if (offset + len > *size)
break;
if (memfread(&mem[offset], 1, len, f) != (size_t) len)
break;
if (undo)
memfseek(f, len, MSEEK_CUR);
count -= 8 + 1 + len;
if (undo)
count -= len;
}
return (count == 0);
}
bool patchApplyPPF(MFILE *f, u8 **rom, int *size)
{
bool res = false;
int version = ppfVersion(f);
switch (version)
{
case 1: res = patchApplyPPF1(f, rom, size); break;
case 2: res = patchApplyPPF2(f, rom, size); break;
case 3: res = patchApplyPPF3(f, rom, size); break;
}
return res;
}
bool applyPatch(const char *patchname, u8 **rom, int *size)
{
bool result = false;
if (strlen(patchname) < 5)
return false;
const char * p = strrchr(patchname, '.');
if (p == NULL)
return false;
FILE *f = fopen(patchname, "rb");
if (!f)
return false;
// read in file
fseek(f, 0, SEEK_END); // go to end of file
int filesize = ftell(f); // get filesize
fseek(f, 0, SEEK_SET); // go to start of file
char * pbuffer = (char *) malloc(filesize);
fread (pbuffer, 1, filesize, f);
fclose(f);
MFILE * mf = memfopen(pbuffer, filesize); // create memory file
if (_stricmp(p, ".ips") == 0)
result = patchApplyIPS(mf, rom, size);
else if (_stricmp(p, ".ups") == 0)
result = patchApplyUPS(mf, rom, size);
else if (_stricmp(p, ".ppf") == 0)
result = patchApplyPPF(mf, rom, size);
memfclose(mf); // close memory file
free(pbuffer); // free buffer
return result;
}