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miserable, feeble little attempt at executing AR codes.

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also, it's hardcoded. probably not a good thing.
This commit is contained in:
Arisotura 2020-02-14 20:13:06 +01:00
parent 106b9a6f24
commit d0b27178f1
1 changed files with 94 additions and 3 deletions
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97
src/AREngine.cpp
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@ -25,8 +25,16 @@
namespace AREngine
{
typedef struct
{
u32 Code[2 * 64]; // TODO: more sensible size for this? allocate on demand?
bool Enabled;
} CheatEntry;
// TODO: more sensible size for this? allocate on demand?
u32 CheatCodes[2 * 1024];
CheatEntry CheatCodes[64];
u32 NumCheatCodes;
bool Init()
@ -41,15 +49,98 @@ void DeInit()
void Reset()
{
memset(CheatCodes, 0, sizeof(u32)*2*1024);
memset(CheatCodes, 0, sizeof(CheatCodes));
NumCheatCodes = 0;
// TODO: acquire codes from a sensible source!
CheatEntry* entry = &CheatCodes[0];
u32* ptr = &entry->Code[0];
#define TEMP_PUTCODE(a, b) *ptr++ = a; *ptr++ = b;
// NSMBDS EUR - giant fucking Mario
TEMP_PUTCODE(0x1209DBD0, 0x0000027C);
TEMP_PUTCODE(0x2209DBC0, 0x00000003);
TEMP_PUTCODE(0x94000130, 0xFFFD0000);
TEMP_PUTCODE(0x1209DBD0, 0x00000000);
TEMP_PUTCODE(0x2209DBC0, 0x00000003);
entry->Enabled = true;
NumCheatCodes++;
}
#define case16(x) \
case ((x)+0x00): case ((x)+0x01): case ((x)+0x02): case ((x)+0x03): \
case ((x)+0x04): case ((x)+0x05): case ((x)+0x06): case ((x)+0x07): \
case ((x)+0x08): case ((x)+0x09): case ((x)+0x0A): case ((x)+0x0B): \
case ((x)+0x0C): case ((x)+0x0D): case ((x)+0x0E): case ((x)+0x0F)
void RunCheat(CheatEntry* entry)
{
u32* code = &entry->Code[0];
u32 cond = 1;
u32 condstack = 0;
for (;;)
{
u32 a = *code++;
u32 b = *code++;
if ((a|b) == 0) break;
u8 op = a >> 24;
if ((op < 0xD0 && op != 0xC5) || op > 0xD2)
{
if (!cond)
{
// TODO: skip parameters for opcode Ex
continue;
}
}
switch (op)
{
case16(0x00): // 32-bit write
NDS::ARM7Write32(a & 0x0FFFFFFF, b);
break;
case16(0x10): // 16-bit write
NDS::ARM7Write16(a & 0x0FFFFFFF, b & 0xFFFF);
break;
case16(0x20): // 8-bit write
NDS::ARM7Write8(a & 0x0FFFFFFF, b & 0xFF);
break;
case16(0x90): // IF b.l = ((~b.h) & u16[a])
{
condstack <<= 1;
condstack |= cond;
u16 val = NDS::ARM7Read16(a & 0x0FFFFFFF);
u16 chk = ~(b >> 16);
chk &= val;
cond = ((b & 0xFFFF) == chk) ? 1:0;
}
break;
default:
printf("!! bad AR opcode %08X %08X\n", a, b);
return;
}
}
}
void RunCheats()
{
// bahahah
// TODO: make it disableable in general
for (u32 i = 0; i < NumCheatCodes; i++)
{
CheatEntry* entry = &CheatCodes[i];
if (entry->Enabled)
RunCheat(entry);
}
}
}