miserable, feeble little attempt at executing AR codes.

also, it's hardcoded. probably not a good thing.

1 files changed, 94 insertions, 3 deletions

diff --git a/src/AREngine.cpp b/src/AREngine.cpp
index 9a87d5d..3049ecb 100644
--- a/src/AREngine.cpp
+++ b/src/AREngine.cpp
@@ -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);
+    }
 }
 
 }