2 files changed, 57 insertions, 1 deletions
diff --git a/arm9/src/game_init.c b/arm9/src/game_init.c
index 9cc12ad2..020d4b75 100644
--- a/arm9/src/game_init.c
+++ b/arm9/src/game_init.c
@@ -7,6 +7,7 @@
 #include "MWC_string.h"
 #include "tp.h"
 #include "unk_0201B4E8.h"
+#include "unk_02022450.h"
 #include "game_init.h"
 #include "registers.h"
 #include "heap.h"
@@ -14,7 +15,17 @@
 
 #pragma thumb on
 
-extern void FUN_02022450(void);
+typedef volatile struct
+{
+    u8 sys_and_irq_stack[0x3F80];
+    u8 svc_stack[0x40];
+    u8 reserved[0x38];
+    u32 intr_check;
+    void * intr_vector;
+}
+OS_DTCM;
+
+#define DTCM (*(OS_DTCM *)HW_DTCM)
 
 static struct {
     void * contents;
diff --git a/arm9/src/unk_02022450.c b/arm9/src/unk_02022450.c
new file mode 100644
index 00000000..7984fcc2
--- /dev/null
+++ b/arm9/src/unk_02022450.c
@@ -0,0 +1,45 @@
+#include "global.h"
+#include "FS_file.h"
+#include "OS_terminate_proc.h"
+#include "CARD_rom.h"
+#include "MI_memory.h"
+
+#include "unk_02022450.h"
+
+static const char string_saying_rom[] = "rom";
+
+/*Replacing (HW_MAIN_MEM_SHARED + 0xC) or (HW_MAIN_MEM_SHARED + 0x10) or defining ADAJ or 01 constants causes match failure*/
+THUMB_FUNC void FUN_02022450 () {
+    if (!FS_IsAvailable()) {
+        OS_Terminate();
+    }
+    else {
+        struct CARD_Header* card_header_buffer = (struct CARD_Header*)HW_MAIN_MEM_SHARED;
+        
+        if (!*(u32*)(HW_MAIN_MEM_SHARED + 0xC)) {
+            CARD_Init();
+            MI_CpuCopy8((u8*)HW_ROM_HEADER_BUF, (u8*)card_header_buffer, HW_CARD_ROM_HEADER_SIZE);
+            MI_CpuCopy8((u8*)HW_ROM_HEADER_BUF, (u8*)HW_CARD_ROM_HEADER, HW_CARD_ROM_HEADER_SIZE);
+            *(u32*)(HW_MAIN_MEM_SHARED + 0xC) = 0x4A414441 /*"ADAJ" LE*/;
+        }
+        FSArchive * const r0 = FS_FindArchive(string_saying_rom, 3);
+        r0->fat = card_header_buffer->header_48;
+        r0->fat_size = card_header_buffer->header_4C;
+        r0->fnt = card_header_buffer->header_40;
+        r0->fnt_size = card_header_buffer->header_44;
+        if (*(u32*)(HW_MAIN_MEM_SHARED + 0xC) != 0x4A414441 /*"ADAJ" LE*/ || *(u16*)(HW_MAIN_MEM_SHARED + 0x10) != 0x3130 /*"01" LE*/) {
+            OS_Terminate();
+        }
+    }
+    return;
+}
+
+THUMB_FUNC void Reset_To_File (const char* path) {
+    FSFile file;
+    FS_InitFile(&file);
+    if (FS_OpenFile(&file, path)) {
+        *(u32*)HW_ROM_BASE_OFFSET_BUF = file.prop.file.top;
+        OS_ResetSystem(0);
+    }
+    return;
+}