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2026-02-02 04:50:13 +01:00

186 lines
6.1 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "common/endian.h"
#include "glk/scott/types.h"
#include "glk/scott/unp64/unp64.h"
#include "glk/scott/unp64/exo_util.h"
namespace Glk {
namespace Scott {
void scnECA(UnpStr *unp) {
byte *mem;
int q, p;
if (unp->_idFlag)
return;
mem = unp->_mem;
if (unp->_depAdr == 0) {
// for(p=0x810;p<0x830;p+=0x4)
for (p = 0x80d; p < 0x830; p += 0x1) {
if (u32eq(mem + p + 0x08, (unsigned int)(0x2D9D0032 + p)) &&
u32eq(mem + p + 0x3a, 0x2a2a2a2a) &&
u32eq(mem + p + 0x0c, 0xF710CA00)) {
if (((*(unsigned int *)(mem + p + 0x00) & 0xf4fff000) == 0x8434A000) &&
u32eq(mem + p + 0x04, 0xBD05A201)) {
unp->_forced = p + 1;
} else if (((*(unsigned int *)(mem + p + 0x00) & 0xffffff00) == 0x04A27800) &&
u32eq(mem + p + 0x04, 0xBDE80186)) {
unp->_forced = p + 1;
} else if (((*(unsigned int *)(mem + p - 0x03) & 0xffffff00) == 0x04A27800) &&
u32eq(mem + p + 0x04, 0xBDE80186)) {
unp->_forced = p - 2;
} else if (u32eq(mem + p - 0x03, 0x8D00a978)) {
unp->_forced = p - 2;
}
}
if (!unp->_forced) {
if (u32eq(mem + p + 0x3a, 0x2a2a2a2a) &&
u32eq(mem + p + 0x02, 0x8534A978) &&
mem[p - 3] == 0xa0) {
unp->_forced = p - 3;
if (mem[p + 0x0d6] == 0x20 && mem[p + 0x0d7] == 0xe0 &&
mem[p + 0x0d8] == 0x03 && mem[p + 0x1da] == 0x5b &&
mem[p + 0x1e7] == 0x59) {
/* antiprotection :D */
mem[p + 0x0d6] = 0x4c;
mem[p + 0x0d7] = 0xae;
mem[p + 0x0d8] = 0xa7;
}
}
}
if (!unp->_forced) { /* FDT */
if (u32eq(mem + p + 0x3a, 0x2a2a2a2a) &&
u32eq(mem + p + 0x03, 0x8604A278) &&
u32eq(mem + p + 0x0a, 0x2D950842)) {
unp->_forced = p + 3;
}
}
if (!unp->_forced) {
/* decibel hacks */
if (u32eq(mem + p + 0x3a, 0x2a2a2a2a) &&
u32eq(mem + p + 0x00, 0x9D085EBD) &&
u32eq(mem + p - 0x06, 0x018534A9)) {
unp->_forced = p - 0x6;
}
}
if (unp->_forced) {
for (q = 0xd6; q < 0xde; q++) {
if (mem[p + q] == 0x20) {
if (u16eq(mem + p + q + 1, 0xa659) ||
u16eq(mem + p + q + 1, 0xff81) ||
u16eq(mem + p + q + 1, 0xe3bf) ||
u16eq(mem + p + q + 1, 0xe5a0) ||
u16eq(mem + p + q + 1, 0xe518)) {
mem[p + q] = 0x2c;
q += 2;
continue;
} else {
unp->_retAdr = READ_LE_UINT16(&mem[p + q + 1]); // mem[p + q + 1] | mem[p + q + 2] << 8;
break;
}
}
if (mem[p + q] == 0x4c) {
unp->_retAdr = READ_LE_UINT16(&mem[p + q + 1]); // mem[p + q + 1] | mem[p + q + 2] << 8;
break;
}
}
unp->_depAdr = READ_LE_UINT16(&mem[p + 0x30]); // mem[p + 0x30] | mem[p + 0x31] << 8;
// some use $2d, some $ae
for (q = 0xed; q < 0x108; q++) {
if (u32eq(mem + p + q, 0xA518F7D0)) {
unp->_endAdr = mem[p + q + 4];
// if(unp->_DebugP)
// printf("EndAdr from $%02x\n",unp->_endAdr);
break;
}
}
/*
if anything it's unpacked to $d000-efff, it will be copied
to $e000-ffff as last action in unpacker before starting.
0196 20 DA 01 JSR $01DA ; some have this jsr nopped, reloc doesn't
happen 0199 A9 37 LDA #$37 019b 85 01 STA $01 019d 58 CLI
019e 20 00 0D JSR $0D00 ; retaddr can be either here or following
01a1 4C AE A7 JMP $A7AE
01da B9 00 EF LDA $EF00,Y
01dd 99 00 FF STA $FF00,Y
01e0 C8 INY
01e1 D0 F7 BNE $01DA
01e3 CE DC 01 DEC $01DC
01e6 CE DF 01 DEC $01DF
01e9 AD DF 01 LDA $01DF
01ec C9 DF CMP #$DF ;<< not fixed, found as lower as $44 for
example 01ee D0 EA BNE $01DA 01f0 60 RTS Because of this,
$d000-dfff will be a copy of $e000-efff. So if $2d points to >= $d000,
SOMETIMES it's better save up to $ffff or: mem[$2d]|(mem[$2e]+$10)<<8
Still it's not a rule and I don't know exactly when.
17/06/09: Implemented but still experimental, so better check
extensively. use -v to know when it does the adjustments. 28/10/09:
whoops, was clearing ONLY $d000-dfff =)
*/
unp->_strMem = READ_LE_UINT16(&mem[p + 0x32]); // mem[p + 0x32] | mem[p + 0x33] << 8;
for (q = 0xcd; q < 0xd0; q++) {
if (u32eqmasked(mem + p + q, 0xffff00ff, 0xa9010020)) {
unp->_ecaFlg = READ_LE_UINT16(&mem[p + q + 1]); // mem[p + q + 1] | mem[p + q + 2] << 8;
for (q = 0x110; q < 0x11f; q++) {
if (u32eq(mem + p + q, 0x99EF00B9) &&
mem[p + q + 0x12] == 0xc9) {
unp->_ecaFlg |= (mem[p + q + 0x13] - 0xf) << 24;
break;
}
}
break;
}
}
/* radwar hack has a BRK here, fffe/f used as IRQ/BRK vector */
if (mem[0x8e1] == 0) {
mem[0x8e1] = 0x6c;
mem[0x8e2] = 0xfe;
mem[0x8e3] = 0xff;
}
break;
}
}
if (unp->_depAdr) {
unp->_idFlag = 1;
return;
}
}
/* old packer, many old 1985 warez used this */
if (unp->_depAdr == 0) {
if (u32eq(mem + 0x81b, 0x018534A9) &&
u32eq(mem + 0x822, 0xAFC600A0) &&
u32eq(mem + 0x826, 0xB1082DCE) &&
u32eq(mem + 0x85b, 0x2A2A2A2A)) {
unp->_forced = 0x81b;
unp->_depAdr = 0x100;
unp->_strMem = READ_LE_UINT16(&mem[0x853]); // mem[0x853] | mem[0x854] << 8;
unp->_endAdr = mem[0x895];
unp->_retAdr = READ_LE_UINT16(&mem[0x885]); // mem[0x885] | mem[0x886] << 8;
unp->_idFlag = 1;
return;
}
}
}
} // End of namespace Scott
} // End of namespace Glk