Better structure for unk_02022450

2 files changed, 67 insertions, 12 deletions

diff --git a/arm9/lib/NitroSDK/include/CARD_rom.h b/arm9/lib/NitroSDK/include/CARD_rom.h
index b6fca60b..fb013cfe 100644
--- a/arm9/lib/NitroSDK/include/CARD_rom.h
+++ b/arm9/lib/NitroSDK/include/CARD_rom.h
@@ -35,6 +35,44 @@ typedef struct
 }
 CARDRomRegion;
 
+typedef struct CARDRomHeader
+{
+    char game_name[12];
+    u32 game_code;
+    u16 maker_code;
+    u8 product_id;
+    u8 device_type;
+    u8 device_size;
+    u8 reserved_A[9];
+    u8 game_version;
+    u8 property;
+    void *main_rom_offset;
+    void *main_entry_address;
+    void *main_ram_address;
+    u32 main_size;
+    void *sub_rom_offset;
+    void *sub_entry_address;
+    void *sub_ram_address;
+    u32 sub_size;
+    CARDRomRegion fnt;
+    CARDRomRegion fat;
+    CARDRomRegion main_ovt;
+    CARDRomRegion sub_ovt;
+    u8 rom_param_A[8];
+    u32 banner_offset;
+    u16 secure_crc;
+    u8 rom_param_B[2];
+    void *main_autoload_done;
+    void *sub_autoload_done;
+    u8 rom_param_C[8];
+    u32 rom_size;
+    u32 header_size;
+    u8 reserved_B[0x38];
+    u8 logo_data[0x9C];
+    u16 logo_crc;
+    u16 header_crc;
+} CARDRomHeader;
+
 typedef struct CARDRomStat
 {
     void (*read_func) (struct CARDRomStat *);
diff --git a/arm9/src/unk_02022450.c b/arm9/src/unk_02022450.c
index 7984fcc2..2c5b9417 100644
--- a/arm9/src/unk_02022450.c
+++ b/arm9/src/unk_02022450.c
@@ -6,35 +6,52 @@
 
 #include "unk_02022450.h"
 
-static const char string_saying_rom[] = "rom";
+static inline u32 GetBakRomCode(void) {
+    return ((CARDRomHeader*)HW_MAIN_MEM_SHARED)->game_code;
+}
+
+static inline void SetBakRomCode(u32 newCode) {
+    ((CARDRomHeader*)HW_MAIN_MEM_SHARED)->game_code = newCode;
+}
+
+static inline u16 GetBakRomMaker(void) {
+    return ((CARDRomHeader*)HW_MAIN_MEM_SHARED)->maker_code;
+}
+
+static const char arc_name[] = "rom";
+
+// Multichar constants are encoded big-endian,
+// but this is a little-endian machine.
+#define ROM_CODE_ADAJ_BE     'JADA'
+#define MAKER_CODE_01_BE     '01'
 
 /*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 () {
+THUMB_FUNC void FUN_02022450() {
     if (!FS_IsAvailable()) {
         OS_Terminate();
     }
     else {
-        struct CARD_Header* card_header_buffer = (struct CARD_Header*)HW_MAIN_MEM_SHARED;
+        CARDRomHeader* card_header_buffer = (CARDRomHeader*)HW_MAIN_MEM_SHARED;
         
-        if (!*(u32*)(HW_MAIN_MEM_SHARED + 0xC)) {
+        if (GetBakRomCode() == 0) {
             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*/;
+            SetBakRomCode(ROM_CODE_ADAJ_BE);
         }
-        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*/) {
+        FSArchive * const r0 = FS_FindArchive(arc_name, 3);
+        r0->fat = card_header_buffer->fat.offset;
+        r0->fat_size = card_header_buffer->fat.length;
+        r0->fnt = card_header_buffer->fnt.offset;
+        r0->fnt_size = card_header_buffer->fnt.length;
+        if (GetBakRomCode() != ROM_CODE_ADAJ_BE || GetBakRomMaker() != MAKER_CODE_01_BE) {
             OS_Terminate();
         }
     }
     return;
 }
 
-THUMB_FUNC void Reset_To_File (const char* path) {
+THUMB_FUNC void Reset_To_File(const char* path) {
     FSFile file;
     FS_InitFile(&file);
     if (FS_OpenFile(&file, path)) {