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[Gamecube/Wii][libretro] added Mega-CD PRG-RAM & Word-RAM cheat codes support

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ekeeke 2022-10-15 16:12:51 +02:00
parent 0f9d57d6b8
commit 98b5c60355
6 changed files with 120 additions and 27 deletions
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builds/genesis_plus_gx_libretro.dll
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builds/genplus_cube.dol
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70
gx/gui/cheats.c
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@ -3,7 +3,7 @@
*
* Genesis Plus GX Cheats menu
*
* Copyright Eke-Eke (2010-2019)
* Copyright Eke-Eke (2010-2022)
*
* Redistribution and use of this code or any derivative works are permitted
* provided that the following conditions are met:
@ -456,7 +456,33 @@ static void apply_cheats(void)
{
if (cheatlist[i].enable)
{
if (cheatlist[i].address < cart.romsize)
/* detect Work RAM patch */
if (cheatlist[i].address >= 0xFF0000)
{
/* add RAM patch */
cheatIndexes[maxRAMcheats++] = i;
}
/* check if Mega-CD game is running */
else if ((system_hw == SYSTEM_MCD) && !scd.cartridge.boot)
{
/* detect PRG-RAM patch (Sub-CPU side) */
if (cheatlist[i].address < 0x80000)
{
/* add RAM patch */
cheatIndexes[maxRAMcheats++] = i;
}
/* detect Word-RAM patch (Main-CPU side)*/
else if ((cheatlist[i].address >= 0x200000) && (cheatlist[i].address < 0x240000))
{
/* add RAM patch */
cheatIndexes[maxRAMcheats++] = i;
}
}
/* detect cartridge ROM patch */
else if (cheatlist[i].address < cart.romsize)
{
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
{
@ -489,20 +515,20 @@ static void apply_cheats(void)
}
}
}
else if (cheatlist[i].address >= 0xFF0000)
{
/* add RAM patch */
cheatIndexes[maxRAMcheats++] = i;
}
}
}
}
static void clear_cheats(void)
{
int i = maxcheats;
int i;
/* disable cheats in reversed order in case the same address is used by multiple patches */
/* no ROM patches with Mega-CD games */
if ((system_hw == SYSTEM_MCD) && !scd.cartridge.boot)
return;
/* disable cheats in reversed order in case the same address is used by multiple ROM patches */
i = maxcheats;
while (i > 0)
{
if (cheatlist[i-1].enable)
@ -1501,6 +1527,8 @@ void CheatLoad(void)
****************************************************************************/
void RAMCheatUpdate(void)
{
uint8 *base;
uint32 mask;
int index, cnt = maxRAMcheats;
while (cnt)
@ -1508,16 +1536,36 @@ void RAMCheatUpdate(void)
/* get cheat index */
index = cheatIndexes[--cnt];
/* detect destination RAM */
switch ((cheatlist[index].address >> 20) & 0xf)
{
case 0x0: /* Mega-CD PRG-RAM (512 KB) */
base = scd.prg_ram;
mask = 0x7fffe;
break;
case 0x2: /* Mega-CD 2M Word-RAM (256 KB) */
base = scd.word_ram_2M;
mask = 0x3fffe;
break;
default: /* Work-RAM (64 KB) */
base = work_ram;
mask = 0xfffe;
break;
}
/* apply RAM patch */
if (cheatlist[index].data & 0xFF00)
{
/* word patch */
*(u16 *)(work_ram + (cheatlist[index].address & 0xFFFE)) = cheatlist[index].data;
*(u16 *)(base + (cheatlist[index].address & mask)) = cheatlist[index].data;
}
else
{
/* byte patch */
work_ram[cheatlist[index].address & 0xFFFF] = cheatlist[index].data;
mask |= 1;
base[cheatlist[index].address & mask] = cheatlist[index].data;
}
}
}

2
gx/gui/cheats.h
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@ -3,7 +3,7 @@
*
* Genesis Plus GX Cheats menu
*
* Copyright Eke-Eke (2010-2019)
* Copyright Eke-Eke (2010-2022)
*
* Redistribution and use of this code or any derivative works are permitted
* provided that the following conditions are met:

75
libretro/libretro.c
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@ -2245,12 +2245,32 @@ static void apply_cheats(void)
{
if (cheatlist[i].address < cart.romsize)
{
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
/* detect Work RAM patch */
if (cheatlist[i].address >= 0xFF0000)
{
/* patch ROM data */
cheatlist[i].old = *(uint16_t *)(cart.rom + (cheatlist[i].address & 0xFFFFFE));
*(uint16_t *)(cart.rom + (cheatlist[i].address & 0xFFFFFE)) = cheatlist[i].data;
/* add RAM patch */
cheatIndexes[maxRAMcheats++] = i;
}
/* check if Mega-CD game is running */
else if ((system_hw == SYSTEM_MCD) && !scd.cartridge.boot)
{
/* detect PRG-RAM patch (Sub-CPU side) */
if (cheatlist[i].address < 0x80000)
{
/* add RAM patch */
cheatIndexes[maxRAMcheats++] = i;
}
/* detect Word-RAM patch (Main-CPU side)*/
else if ((cheatlist[i].address >= 0x200000) && (cheatlist[i].address < 0x240000))
{
/* add RAM patch */
cheatIndexes[maxRAMcheats++] = i;
}
}
/* detect cartridge ROM patch */
else
{
/* add ROM patch */
@ -2273,19 +2293,20 @@ static void apply_cheats(void)
}
}
}
else if (cheatlist[i].address >= 0xFF0000)
{
/* add RAM patch */
cheatIndexes[maxRAMcheats++] = i;
}
}
}
}
static void clear_cheats(void)
{
int i = maxcheats;
/* disable cheats in reversed order in case the same address is used by multiple patches */
int i;
/* no ROM patches with Mega-CD games */
if ((system_hw == SYSTEM_MCD) && !scd.cartridge.boot)
return;
/* disable cheats in reversed order in case the same address is used by multiple ROM patches */
i = maxcheats;
while (i > 0)
{
if (cheatlist[i-1].enable)
@ -2322,21 +2343,45 @@ static void clear_cheats(void)
****************************************************************************/
static void RAMCheatUpdate(void)
{
uint8_t *base;
uint32_t mask;
int index, cnt = maxRAMcheats;
while (cnt)
{
/* get cheat index */
index = cheatIndexes[--cnt];
/* detect destination RAM */
switch ((cheatlist[index].address >> 20) & 0xf)
{
case 0x0: /* Mega-CD PRG-RAM (512 KB) */
base = scd.prg_ram;
mask = 0x7fffe;
break;
case 0x2: /* Mega-CD 2M Word-RAM (256 KB) */
base = scd.word_ram_2M;
mask = 0x3fffe;
break;
default: /* Work-RAM (64 KB) */
base = work_ram;
mask = 0xfffe;
break;
}
/* apply RAM patch */
if (cheatlist[index].data & 0xFF00)
{
/* 16-bit patch */
*(uint16_t *)(work_ram + (cheatlist[index].address & 0xFFFE)) = cheatlist[index].data;
/* word patch */
*(uint16_t *)(base + (cheatlist[index].address & mask)) = cheatlist[index].data;
}
else
{
/* 8-bit patch */
work_ram[cheatlist[index].address & 0xFFFF] = cheatlist[index].data;
/* byte patch */
mask |= 1;
base[cheatlist[index].address & mask] = cheatlist[index].data;
}
}
}