oss/RomPatcher.js
oss/RomPatcher.js
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added support for APS (GBA), fixing #58

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Marc Robledo 2023-03-31 19:08:27 +02:00
parent 0769fae972
commit 1ea536ad27
9 changed files with 147 additions and 133 deletions
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133
js/crc.js
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@ -108,126 +108,19 @@ function adler32(marcFile, offset, len){
/* CRC16 */
/*
const CRC16_TABLE=(function(){
var c,crcTable=[];
for(var n=0;n<256;n++){
c=n;
for(var k=0;k<8;k++)
c=((c&1)?(0x8408^(c>>>1)):(c>>>1));
crcTable[n]=c;
/* CRC16/CCITT-FALSE */
function crc16(marcFile, offset, len){
var crc=0xffff;
offset=offset? offset : 0;
len=len && len>0? len : marcFile.fileSize;
for(var i=0; i<len; i++){
crc ^= marcFile._u8array[offset++] << 8;
for (j=0; j<8; ++j) {
crc = (crc & 0x8000) >>> 0 ? (crc << 1) ^ 0x1021 : crc << 1;
}
}
return crcTable;
}());
function crc16(marcFile){
var crc=0^(-1);
for(var i=0;i<marcFile._u8array.length;i++)
crc=((crc>>>8)&0x0ff)^CRC16_TABLE[(crc^marcFile._u8array[i])&0xff];
return ((crc^(-1))>>>0) & 0xffff;
return crc & 0xffff;
}
*/
/* specific ROM checksums */
/* this is unused code, might be used in a future so ROM checksums can be fixed after patching */
const CONSOLES=[
{
title:'Sega Mega Drive/Genesis',
MEGADRIVE_LOGO:[0x53, 0x45, 0x47, 0x41, 0x20, 0x4d, 0x45, 0x47, 0x41, 0x20, 0x44, 0x52],
GENESIS_LOGO:[0x53, 0x45, 0x47, 0x41, 0x20, 0x47, 0x45, 0x4e, 0x45, 0x53, 0x49, 0x53],
checkHeader:function(marcFile){
var megadrive=true;
var genesis=true;
for(var i=0; i<12 && (megadrive || genesis); i++){
if(marcFile._u8array[0x100+i]!==this.MEGADRIVE_LOGO[i])
megadrive=false;
if(marcFile._u8array[0x100+i]!==this.GENESIS_LOGO[i])
genesis=false;
}
return megadrive || genesis;
},
getChecksum:function(marcFile){
return (marcFile._u8array[0x018e]<<8) + marcFile._u8array[0x018f];
},
recalculateChecksum:function(marcFile){
var checksum=0;
for(var i=0x200; i<marcFile.fileSize; i+=2)
checksum=(checksum + (((marcFile._u8array[i]<<8) + marcFile._u8array[i+1])>>>0)) & 0xffff;
return checksum
},
updateChecksum:function(marcFile, newChecksum){
marcFile._u8array[0x18e]=newChecksum>>8;
marcFile._u8array[0x18f]=newChecksum & 0xff;
}
},{
title:'Game Boy',
NINTENDO_LOGO:[0xce, 0xed, 0x66, 0x66, 0xcc, 0x0d, 0x00, 0x0b, 0x03, 0x73, 0x00, 0x83, 0x00, 0x0c, 0x00, 0x0d],
checkHeader:function(marcFile){
for(var i=0; i<this.NINTENDO_LOGO.length; i++){
if(marcFile._u8array[0x104+i]!==this.NINTENDO_LOGO[i])
return false;
}
return true;
},
getChecksum:function(marcFile){
return marcFile._u8array[0x14d]
},
recalculateChecksum:function(marcFile){
var checksum=0;
for(var i=0x134; i<0x014d; i++){
checksum=(checksum - marcFile._u8array[i] - 1) & 0xff;
}
return checksum
},
updateChecksum:function(marcFile, newChecksum){
marcFile._u8array[0x014d]=newChecksum;
/* global checksum isn't checked by real hw, but fix it anyway */
var globalChecksumOld=(marcFile._u8array[0x014e]<<8) + marcFile._u8array[0x014f];
var globalChecksumNew=0;
for(var i=0x0000; i<0x014e; i++)
globalChecksumNew=((globalChecksumNew + marcFile._u8array[i]) >>> 0) & 0xffff;
for(i=0x0150;i<marcFile.fileSize; i++)
globalChecksumNew=((globalChecksumNew + marcFile._u8array[i]) >>> 0) & 0xffff;
if(globalChecksumOld!==globalChecksumNew){
marcFile._u8array[0x014e]=globalChecksumNew>>8;
marcFile._u8array[0x014f]=globalChecksumNew & 0xff;
}
}
}
];
function checkConsole(marcFile){
return false;
}
function fixConsoleChecksum(marcFile){
var system=false;
for(var i=0; i<CONSOLES.length && !system; i++)
if(CONSOLES[i].checkHeader(marcFile))
system=CONSOLES[i];
if(!system)
return false;
var oldChecksum=console.getChecksum(marcFile);
var newChecksum=console.recalculateChecksum(marcFile);
if(oldChecksum!==newChecksum)
if(alert('Fix '+console.title+' checksum?')){
console.updateChecksum(marcFile, newChecksum);
return true;
}
return false;
}