Merge pull request #4 from nullableVoidPtr/master

Overhaul

11 files changed, 2254 insertions, 47 deletions

diff --git a/src/bg_palette_buffer.c b/src/bg_palette_buffer.c
new file mode 100644
index 0000000..9917adf
--- /dev/null
+++ b/src/bg_palette_buffer.c
@@ -0,0 +1,248 @@
+#include "global.h"
+
+#define BG_PALETTE_BUFFER_SIZE 512
+#define BG_PALETTE_BUFFER_CHUNK_SIZE 16
+
+extern u16 gBGPaletteBuffer[BG_PALETTE_BUFFER_SIZE];
+extern bool8 gBGPaletteUsed[BG_PALETTE_BUFFER_SIZE / BG_PALETTE_BUFFER_CHUNK_SIZE];
+
+extern void CpuCopy(void* src, void* dest, u32 size);
+
+#ifndef NONMATCHING
+NAKED
+#endif
+void InitBGPaletteBuffer(void)
+{
+#ifdef NONMATCHING
+    u16 color = 0;
+    u16* ptr;
+    u32 i;
+    bool8 paletteUsed;
+
+    u8* p;
+
+    ptr = gBGPaletteBuffer;
+
+    i = 0x80;
+    i <<= 2;
+
+    do {
+        *ptr++ = color;
+        i--;
+    } while (i);
+
+    paletteUsed = TRUE;
+
+    p = gBGPaletteUsed;
+    p += 31;
+
+    do
+        *p-- = paletteUsed;
+    while ((s32) p >= (s32) &gBGPaletteUsed);
+#else
+    asm_unified("\tpush {lr}\n"
+        "\tmovs r2, 0\n"
+        "\tldr r1, =gBGPaletteBuffer\n"
+        "\tmovs r0, 0x80\n"
+        "\tlsls r0, 2\n"
+        "_0800463E:\n"
+        "\tstrh r2, [r1]\n"
+        "\tadds r1, 0x2\n"
+        "\tsubs r0, 0x1\n"
+        "\tcmp r0, 0\n"
+        "\tbne _0800463E\n"
+        "\tldr r1, =gBGPaletteUsed\n"
+        "\tmovs r2, 0x1\n"
+        "\tadds r0, r1, 0\n"
+        "\tadds r0, 0x1F\n"
+        "_08004650:\n"
+        "\tstrb r2, [r0]\n"
+        "\tsubs r0, 0x1\n"
+        "\tcmp r0, r1\n"
+        "\tbge _08004650\n"
+        "\tpop {r0}\n"
+        "\tbx r0\n"
+        "\t.align 2, 0\n"
+        "\t.pool");
+#endif
+}
+
+#ifndef NONMATCHING
+NAKED
+#endif
+void SetBGPaletteBufferColorRGB(s32 index, u8 *RGBArray, s32 a1, u8 *a2)
+{
+#ifdef NONMATCHING
+    if (a1 < 0) {
+        a1 = 0;
+    }
+    if (a1 > 31) {
+        a1 = 31;
+    }
+    gBGPaletteUsed[index / 16] = 1;
+    if (!a2) {
+        gBGPaletteBuffer[index] = ((RGBArray[2] * a1 / 256 & 0x1F) << 10) | ((RGBArray[1] * a1 / 256 & 0x1F) << 5) | (RGBArray[0] * a1 / 256 & 0x1F);
+    }
+    else
+    {
+        gBGPaletteBuffer[index] = ((a2[4 * RGBArray[2] + 2] * a1 / 256 & 0x1F) << 10) | ((a2[4 * RGBArray[1] + 1] * a1 / 256 & 0x1F) << 5) | (a2[4 * RGBArray[0]] * a1 / 256 & 0x1F);
+    }
+#else
+    asm_unified("\tpush {r4-r7,lr}\n"
+        "\tadds r4, r0, 0\n"
+        "\tadds r5, r1, 0\n"
+        "\tcmp r2, 0\n"
+        "\tbge _08004670\n"
+        "\tmovs r2, 0\n"
+        "_08004670:\n"
+        "\tcmp r2, 0x1F\n"
+        "\tble _08004676\n"
+        "\tmovs r2, 0x1F\n"
+        "_08004676:\n"
+        "\tldr r1, =gBGPaletteUsed\n"
+        "\tadds r0, r4, 0\n"
+        "\tcmp r4, 0\n"
+        "\tbge _08004680\n"
+        "\tadds r0, 0xF\n"
+        "_08004680:\n"
+        "\tasrs r0, 4\n"
+        "\tadds r0, r1\n"
+        "\tmovs r1, 0x1\n"
+        "\tstrb r1, [r0]\n"
+        "\tcmp r3, 0\n"
+        "\tbne _080046D4\n"
+        "\tldr r0, =gBGPaletteBuffer\n"
+        "\tlsls r1, r4, 1\n"
+        "\tadds r6, r1, r0\n"
+        "\tldrb r0, [r5, 0x2]\n"
+        "\tmuls r0, r2\n"
+        "\tcmp r0, 0\n"
+        "\tbge _0800469C\n"
+        "\tadds r0, 0xFF\n"
+        "_0800469C:\n"
+        "\tasrs r0, 8\n"
+        "\tmovs r3, 0x1F\n"
+        "\tands r0, r3\n"
+        "\tlsls r4, r0, 10\n"
+        "\tldrb r0, [r5, 0x1]\n"
+        "\tmuls r0, r2\n"
+        "\tcmp r0, 0\n"
+        "\tbge _080046AE\n"
+        "\tadds r0, 0xFF\n"
+        "_080046AE:\n"
+        "\tasrs r0, 8\n"
+        "\tands r0, r3\n"
+        "\tlsls r1, r0, 5\n"
+        "\torrs r1, r4\n"
+        "\tldrb r0, [r5]\n"
+        "\tmuls r0, r2\n"
+        "\tcmp r0, 0\n"
+        "\tbge _080046C0\n"
+        "\tadds r0, 0xFF\n"
+        "_080046C0:\n"
+        "\tasrs r0, 8\n"
+        "\tands r0, r3\n"
+        "\torrs r1, r0\n"
+        "\tstrh r1, [r6]\n"
+        "\tb _08004722\n"
+        "\t.align 2, 0\n"
+        "\t.pool\n"
+        "_080046D4:\n"
+        "\tldr r1, =gBGPaletteBuffer\n"
+        "\tlsls r0, r4, 1\n"
+        "\tadds r7, r0, r1\n"
+        "\tldrb r0, [r5, 0x2]\n"
+        "\tlsls r0, 2\n"
+        "\tadds r0, r3\n"
+        "\tldrb r0, [r0, 0x2]\n"
+        "\tmuls r0, r2\n"
+        "\tcmp r0, 0\n"
+        "\tbge _080046EA\n"
+        "\tadds r0, 0xFF\n"
+        "_080046EA:\n"
+        "\tasrs r0, 8\n"
+        "\tmovs r4, 0x1F\n"
+        "\tands r0, r4\n"
+        "\tlsls r6, r0, 10\n"
+        "\tldrb r0, [r5, 0x1]\n"
+        "\tlsls r0, 2\n"
+        "\tadds r0, r3\n"
+        "\tldrb r0, [r0, 0x1]\n"
+        "\tmuls r0, r2\n"
+        "\tcmp r0, 0\n"
+        "\tbge _08004702\n"
+        "\tadds r0, 0xFF\n"
+        "_08004702:\n"
+        "\tasrs r0, 8\n"
+        "\tands r0, r4\n"
+        "\tlsls r1, r0, 5\n"
+        "\torrs r1, r6\n"
+        "\tldrb r0, [r5]\n"
+        "\tlsls r0, 2\n"
+        "\tadds r0, r3\n"
+        "\tldrb r0, [r0]\n"
+        "\tmuls r0, r2\n"
+        "\tcmp r0, 0\n"
+        "\tbge _0800471A\n"
+        "\tadds r0, 0xFF\n"
+        "_0800471A:\n"
+        "\tasrs r0, 8\n"
+        "\tands r0, r4\n"
+        "\torrs r1, r0\n"
+        "\tstrh r1, [r7]\n"
+        "_08004722:\n"
+        "\tpop {r4-r7}\n"
+        "\tpop {r0}\n"
+        "\tbx r0\n"
+        "\t.align 2, 0\n"
+        "\t.pool");
+#endif
+}
+
+void SetBGPaletteBufferColorArray(s32 index, u8 *colorArray)
+{
+    gBGPaletteUsed[index / BG_PALETTE_BUFFER_CHUNK_SIZE] = TRUE;
+    gBGPaletteBuffer[index] = (colorArray[2] >> 3) << 10 | (colorArray[1] >> 3) << 5 | colorArray[0] >> 3;
+}
+
+void SetBGPaletteBufferColor(s32 index, u16 *color)
+{
+    gBGPaletteUsed[index / BG_PALETTE_BUFFER_CHUNK_SIZE] = TRUE;
+    gBGPaletteBuffer[index] = *color;
+}
+
+void nullsub_4(void)
+{
+
+}
+void nullsub_5(void)
+{
+
+}
+void nullsub_143(void)
+{
+
+}
+
+void TransferBGPaletteBuffer(void)
+{
+    u32 i;
+    s32 paletteBufferIndex;
+    u16 *dest;
+
+    i = 0;
+    paletteBufferIndex = 0;
+    dest = (u16 *)PLTT;
+    do
+    {
+        if (gBGPaletteUsed[i])
+        {
+            gBGPaletteUsed[i] = 0;
+            CpuCopy(dest, &gBGPaletteBuffer[paletteBufferIndex], sizeof(u16) * 16);
+        }
+        ++i;
+        dest += 16;
+        paletteBufferIndex += 16;
+    }
+    while ( paletteBufferIndex < BG_PALETTE_BUFFER_SIZE );
+}
diff --git a/src/file_system.c b/src/file_system.c
index 296478d..61d9ec4 100644
--- a/src/file_system.c
+++ b/src/file_system.c
@@ -1,33 +1,9 @@
 #include "global.h"
+#include "file_system.h"
 
-struct File
-{
-    char *name;
-    u8 *data;
-};
-
-struct OpenedFile
-{
-    struct File *file;
-    u8 *data;
-};
-
-struct FileArchive
-{
-    char magic[8];
-    s32 count;
-    struct File *entries;
-};
-
-struct SiroArchive
-{
-    u32 magic;
-    u8 *data;
-};
-
-extern struct OpenedFile gUnknown_202D2A8[];
+extern struct OpenedFile gFileCache[64];
 
-extern u32 gUnknown_203B094;
+extern u32 gFileCacheCursorPosition;
 extern u32 gUnknown_202D2A4;
 
 extern int sprintf(char *, const char *, ...);
@@ -41,11 +17,11 @@ void InitFileSystem(void)
 
     for (i = 0; i < 64; i++)
     {
-        gUnknown_202D2A8[i].file = NULL;
-        gUnknown_202D2A8[i].data = NULL;
+        gFileCache[i].file = NULL;
+        gFileCache[i].data = NULL;
     }
 
-    gUnknown_203B094 = 0;
+    gFileCacheCursorPosition = 0;
     gUnknown_202D2A4 = 1;
 }
 
@@ -56,14 +32,14 @@ u32 sub_800A8F8(u32 value)
     return oldValue;
 }
 
-struct OpenedFile *OpenFile(char *filename, struct FileArchive *arc)
+struct OpenedFile *OpenFile(const char *filename, const struct FileArchive *arc)
 {
     char buffer[0x12C];
     s32 left, right;
     s32 cursor;
     s32 i;
-    s32 magic = 0;
-    s32 magicFound;
+    u32 magic = 0;
+    bool32 magicFound;
     struct File *entries;
     struct File *file;
 
@@ -71,7 +47,7 @@ struct OpenedFile *OpenFile(char *filename, struct FileArchive *arc)
 
     magicFound = 0;
 
-    if (!(u8)magic)
+    if (!(bool8)magic)
         magicFound = 1;
 
     if (!magicFound)
@@ -108,18 +84,18 @@ struct OpenedFile *OpenFile(char *filename, struct FileArchive *arc)
         return NULL;
     }
 
-    cursor = gUnknown_203B094;
+    cursor = gFileCacheCursorPosition;
 
     for (i = 0; i < 64; i++)
     {
         cursor++;
         if (cursor > 63)
             cursor = 0;
-        if (!gUnknown_202D2A8[cursor].file)
+        if (!gFileCache[cursor].file)
         {
-            gUnknown_202D2A8[cursor].file = file;
-            gUnknown_202D2A8[cursor].data = NULL;
-            return &gUnknown_202D2A8[cursor];
+            gFileCache[cursor].file = file;
+            gFileCache[cursor].data = NULL;
+            return &gFileCache[cursor];
         }
     }
 
@@ -138,7 +114,7 @@ u8 *GetFileDataPtr(struct OpenedFile *openedFile, int unused)
     return GetSiroPtr(openedFile);
 }
 
-struct OpenedFile *OpenFileAndGetFileDataPtr(char *filename, struct FileArchive *arc)
+struct OpenedFile *OpenFileAndGetFileDataPtr(const char *filename, const struct FileArchive *arc)
 {
     struct OpenedFile *openedFile = OpenFile(filename, arc);
     if (openedFile)
@@ -146,7 +122,7 @@ struct OpenedFile *OpenFileAndGetFileDataPtr(char *filename, struct FileArchive
     return openedFile;
 }
 
-struct OpenedFile *Call_OpenFileAndGetFileDataPtr(char *filename, struct FileArchive *arc)
+struct OpenedFile *Call_OpenFileAndGetFileDataPtr(const char *filename, const struct FileArchive *arc)
 {
     return OpenFileAndGetFileDataPtr(filename, arc);
 }
@@ -157,11 +133,11 @@ void CloseFile(struct OpenedFile *openedFile)
 
     for (i = 0; i < 64; i++)
     {
-        if (&gUnknown_202D2A8[i] == openedFile)
+        if (&gFileCache[i] == openedFile)
         {
-            gUnknown_202D2A8[i].file = NULL;
-            gUnknown_202D2A8[i].data = NULL;
-            gUnknown_203B094 = i;
+            gFileCache[i].file = NULL;
+            gFileCache[i].data = NULL;
+            gFileCacheCursorPosition = i;
             return;
         }
     }
diff --git a/src/flash.c b/src/flash.c
index b9ccf40..11520b4 100644
--- a/src/flash.c
+++ b/src/flash.c
@@ -1,12 +1,11 @@
 #include "global.h"
 #include "gba/flash.h"
 #include "flash.h"
+#include "memory.h"
 
 extern u8 gFlashEnabled;
 
 extern FlashIntrFunc *sub_800B6E8(s32);
-extern void MemoryFill8(void *, u8, s32);
-extern void MemoryCopy8(void *, void *, s32);
 
 static u8 TryProgramSector(s32, u8 *);
 
diff --git a/src/m4a_2.c b/src/m4a_2.c
new file mode 100644
index 0000000..ce9ac19
--- /dev/null
+++ b/src/m4a_2.c
@@ -0,0 +1,947 @@
+#include "gba/m4a_internal.h"
+#include "global.h"
+
+extern char SoundMainRAM_Buffer[0x400];
+
+extern struct SoundInfo gSoundInfo;
+
+
+u32 MidiKeyToFreq(struct WaveData *wav, u8 key, u8 fineAdjust)
+{
+    u32 val1;
+    u32 val2;
+    u32 fineAdjustShifted = fineAdjust << 24;
+
+    if (key > 178)
+    {
+        key = 178;
+        fineAdjustShifted = 255 << 24;
+    }
+
+    val1 = gScaleTable[key];
+    val1 = gFreqTable[val1 & 0xF] >> (val1 >> 4);
+
+    val2 = gScaleTable[key + 1];
+    val2 = gFreqTable[val2 & 0xF] >> (val2 >> 4);
+
+    return umul3232H32(wav->freq, val1 + umul3232H32(val2 - val1, fineAdjustShifted));
+}
+
+void UnusedDummyFunc()
+{
+}
+
+void MPlayContinue(struct MusicPlayerInfo *mplayInfo)
+{
+    if (mplayInfo->ident == ID_NUMBER)
+    {
+        mplayInfo->ident++;
+        mplayInfo->status &= ~MUSICPLAYER_STATUS_PAUSE;
+        mplayInfo->ident = ID_NUMBER;
+    }
+}
+
+void MPlayFadeOut(struct MusicPlayerInfo *mplayInfo, u16 speed)
+{
+    if (mplayInfo->ident == ID_NUMBER)
+    {
+        mplayInfo->ident++;
+        mplayInfo->fadeOC = speed;
+        mplayInfo->fadeOI = speed;
+        mplayInfo->fadeOV = (64 << FADE_VOL_SHIFT);
+        mplayInfo->ident = ID_NUMBER;
+    }
+}
+
+void m4aSoundInit(void)
+{
+    s32 i;
+
+    CpuCopy32((void *)((s32)SoundMainRAM & ~1), SoundMainRAM_Buffer, sizeof(SoundMainRAM_Buffer));
+
+    SoundInit(&gSoundInfo);
+    MPlayExtender(gCgbChans);
+    m4aSoundMode(SOUND_MODE_DA_BIT_8
+               | SOUND_MODE_FREQ_18157
+               | (14 << SOUND_MODE_MASVOL_SHIFT)
+               | (5 << SOUND_MODE_MAXCHN_SHIFT));
+
+    for (i = 0; i < NUM_MUSIC_PLAYERS; i++)
+    {
+        struct MusicPlayerInfo *mplayInfo = gMPlayTable[i].info;
+        MPlayOpen(mplayInfo, gMPlayTable[i].track, gMPlayTable[i].unk_8);
+        mplayInfo->unk_B = gMPlayTable[i].unk_A;
+        mplayInfo->memAccArea = gMPlayMemAccArea;
+    }
+}
+
+void m4aSoundMain(void)
+{
+    SoundMain();
+}
+
+void m4aSongNumStart(u16 n)
+{
+    const struct MusicPlayer *mplayTable = gMPlayTable;
+    const struct Song *songTable = gSongTable;
+    const struct Song *song = &songTable[n];
+    const struct MusicPlayer *mplay = &mplayTable[song->ms];
+
+    MPlayStart(mplay->info, song->header);
+}
+
+void m4aSongNumStartOrChange(u16 n)
+{
+    const struct MusicPlayer *mplayTable = gMPlayTable;
+    const struct Song *songTable = gSongTable;
+    const struct Song *song = &songTable[n];
+    const struct MusicPlayer *mplay = &mplayTable[song->ms];
+
+    if (mplay->info->songHeader != song->header)
+    {
+        MPlayStart(mplay->info, song->header);
+    }
+    else
+    {
+        if ((mplay->info->status & MUSICPLAYER_STATUS_TRACK) == 0
+         || (mplay->info->status & MUSICPLAYER_STATUS_PAUSE))
+        {
+            MPlayStart(mplay->info, song->header);
+        }
+    }
+}
+
+void m4aSongNumStartOrContinue(u16 n)
+{
+    const struct MusicPlayer *mplayTable = gMPlayTable;
+    const struct Song *songTable = gSongTable;
+    const struct Song *song = &songTable[n];
+    const struct MusicPlayer *mplay = &mplayTable[song->ms];
+
+    if (mplay->info->songHeader != song->header)
+        MPlayStart(mplay->info, song->header);
+    else if ((mplay->info->status & MUSICPLAYER_STATUS_TRACK) == 0)
+        MPlayStart(mplay->info, song->header);
+    else if (mplay->info->status & MUSICPLAYER_STATUS_PAUSE)
+        MPlayContinue(mplay->info);
+}
+
+
+void m4aSongNumStop(u16 n)
+{
+    const struct MusicPlayer *mplayTable = gMPlayTable;
+    const struct Song *songTable = gSongTable;
+    const struct Song *song = &songTable[n];
+    const struct MusicPlayer *mplay = &mplayTable[song->ms];
+
+    if (mplay->info->songHeader == song->header)
+        m4aMPlayStop(mplay->info);
+}
+
+void m4aSongNumContinue(u16 n)
+{
+    const struct MusicPlayer *mplayTable = gMPlayTable;
+    const struct Song *songTable = gSongTable;
+    const struct Song *song = &songTable[n];
+    const struct MusicPlayer *mplay = &mplayTable[song->ms];
+
+    if (mplay->info->songHeader == song->header)
+        MPlayContinue(mplay->info);
+}
+
+void m4aMPlayAllStop(void)
+{
+    s32 i;
+
+    for (i = 0; i < NUM_MUSIC_PLAYERS; i++)
+        m4aMPlayStop(gMPlayTable[i].info);
+}
+
+void m4aMPlayContinue(struct MusicPlayerInfo *mplayInfo)
+{
+    MPlayContinue(mplayInfo);
+}
+
+void m4aMPlayAllContinue(void)
+{
+    s32 i;
+
+    for (i = 0; i < NUM_MUSIC_PLAYERS; i++)
+        MPlayContinue(gMPlayTable[i].info);
+}
+
+void m4aMPlayFadeOut(struct MusicPlayerInfo *mplayInfo, u16 speed)
+{
+    MPlayFadeOut(mplayInfo, speed);
+}
+
+void m4aMPlayFadeOutTemporarily(struct MusicPlayerInfo *mplayInfo, u16 speed)
+{
+    if (mplayInfo->ident == ID_NUMBER)
+    {
+        mplayInfo->ident++;
+        mplayInfo->fadeOC = speed;
+        mplayInfo->fadeOI = speed;
+        mplayInfo->fadeOV = (64 << FADE_VOL_SHIFT) | TEMPORARY_FADE;
+        mplayInfo->ident = ID_NUMBER;
+    }
+}
+void m4aMPlayFadeIn(struct MusicPlayerInfo *mplayInfo, u16 speed)
+{
+    if (mplayInfo->ident == ID_NUMBER)
+    {
+        mplayInfo->ident++;
+        mplayInfo->fadeOC = speed;
+        mplayInfo->fadeOI = speed;
+        mplayInfo->fadeOV = (0 << FADE_VOL_SHIFT) | FADE_IN;
+        mplayInfo->status &= ~MUSICPLAYER_STATUS_PAUSE;
+        mplayInfo->ident = ID_NUMBER;
+    }
+}
+
+void m4aMPlayImmInit(struct MusicPlayerInfo *mplayInfo)
+{
+    s32 trackCount = mplayInfo->trackCount;
+    struct MusicPlayerTrack *track = mplayInfo->tracks;
+
+    while (trackCount > 0)
+    {
+        if (track->flags & MPT_FLG_EXIST)
+        {
+            if (track->flags & MPT_FLG_START)
+            {
+                Clear64byte(track);
+                track->flags = MPT_FLG_EXIST;
+                track->bendRange = 2;
+                track->volX = 64;
+                track->lfoSpeed = 22;
+                track->tone.type = 1;
+            }
+        }
+
+        trackCount--;
+        track++;
+    }
+}
+
+void MPlayExtender(struct CgbChannel *cgbChans)
+{
+    struct SoundInfo *soundInfo;
+    u32 ident;
+
+    REG_SOUNDCNT_X = SOUND_MASTER_ENABLE
+                   | SOUND_4_ON
+                   | SOUND_3_ON
+                   | SOUND_2_ON
+                   | SOUND_1_ON;
+    REG_SOUNDCNT_L = 0; // set master volume to zero
+    REG_NR12 = 0x8;
+    REG_NR22 = 0x8;
+    REG_NR42 = 0x8;
+    REG_NR14 = 0x80;
+    REG_NR24 = 0x80;
+    REG_NR44 = 0x80;
+    REG_NR30 = 0;
+    REG_NR50 = 0x77;
+
+    soundInfo = SOUND_INFO_PTR;
+
+    ident = soundInfo->ident;
+
+    if (ident != ID_NUMBER)
+        return;
+
+    soundInfo->ident++;
+
+    gMPlayJumpTable[8] = ply_memacc;
+    gMPlayJumpTable[17] = ply_lfos;
+    gMPlayJumpTable[19] = ply_mod;
+    gMPlayJumpTable[28] = ply_xcmd;
+    gMPlayJumpTable[29] = ply_endtie;
+    gMPlayJumpTable[30] = SampleFreqSet;
+    gMPlayJumpTable[31] = TrackStop;
+    gMPlayJumpTable[32] = FadeOutBody;
+    gMPlayJumpTable[33] = TrkVolPitSet;
+
+    soundInfo->cgbChans = (struct CgbChannel *)cgbChans;
+    soundInfo->CgbSound = CgbSound;
+    soundInfo->CgbOscOff = CgbOscOff;
+    soundInfo->MidiKeyToCgbFreq = MidiKeyToCgbFreq;
+    soundInfo->maxLines = MAX_LINES;
+
+    CpuFill32(0, cgbChans, sizeof(struct CgbChannel) * 4);
+
+    cgbChans[0].ty = 1;
+    cgbChans[0].panMask = 0x11;
+    cgbChans[1].ty = 2;
+    cgbChans[1].panMask = 0x22;
+    cgbChans[2].ty = 3;
+    cgbChans[2].panMask = 0x44;
+    cgbChans[3].ty = 4;
+    cgbChans[3].panMask = 0x88;
+
+    soundInfo->ident = ident;
+}
+
+void MusicPlayerJumpTableCopy(void)
+{
+    asm("swi 0x2A");
+}
+
+void ClearChain(void *x)
+{
+    void (*func)(void *) = *(&gMPlayJumpTable[34]);
+    func(x);
+}
+
+void Clear64byte(void *x)
+{
+    void (*func)(void *) = *(&gMPlayJumpTable[35]);
+    func(x);
+}
+
+void SoundInit(struct SoundInfo *soundInfo)
+{
+    soundInfo->ident = 0;
+
+    if (REG_DMA1CNT & (DMA_REPEAT << 16))
+        REG_DMA1CNT = ((DMA_ENABLE | DMA_START_NOW | DMA_32BIT | DMA_SRC_INC | DMA_DEST_FIXED) << 16) | 4;
+
+    if (REG_DMA2CNT & (DMA_REPEAT << 16))
+        REG_DMA2CNT = ((DMA_ENABLE | DMA_START_NOW | DMA_32BIT | DMA_SRC_INC | DMA_DEST_FIXED) << 16) | 4;
+
+    REG_DMA1CNT_H = DMA_32BIT;
+    REG_DMA2CNT_H = DMA_32BIT;
+    REG_SOUNDCNT_X = SOUND_MASTER_ENABLE
+                   | SOUND_4_ON
+                   | SOUND_3_ON
+                   | SOUND_2_ON
+                   | SOUND_1_ON;
+    REG_SOUNDCNT_H = SOUND_B_FIFO_RESET | SOUND_B_TIMER_0 | SOUND_B_LEFT_OUTPUT
+                   | SOUND_A_FIFO_RESET | SOUND_A_TIMER_0 | SOUND_A_RIGHT_OUTPUT
+                   | SOUND_ALL_MIX_FULL;
+    REG_SOUNDBIAS_H = (REG_SOUNDBIAS_H & 0x3F) | 0x40;
+
+    REG_DMA1SAD = (s32)soundInfo->pcmBuffer;
+    REG_DMA1DAD = (s32)&REG_FIFO_A;
+    REG_DMA2SAD = (s32)soundInfo->pcmBuffer + PCM_DMA_BUF_SIZE;
+    REG_DMA2DAD = (s32)&REG_FIFO_B;
+
+    SOUND_INFO_PTR = soundInfo;
+    CpuFill32(0, soundInfo, sizeof(struct SoundInfo));
+
+    soundInfo->maxChans = 8;
+    soundInfo->masterVolume = 15;
+    soundInfo->plynote = (u32)ply_note;
+    soundInfo->CgbSound = DummyFunc;
+    soundInfo->CgbOscOff = (void (*)(u8))DummyFunc;
+    soundInfo->MidiKeyToCgbFreq = (u32 (*)(u8, u8, u8))DummyFunc;
+    soundInfo->ExtVolPit = (u32)DummyFunc;
+
+    MPlayJumpTableCopy(gMPlayJumpTable);
+
+    soundInfo->MPlayJumpTable = (u32)gMPlayJumpTable;
+
+    SampleFreqSet(SOUND_MODE_FREQ_13379);
+
+    soundInfo->ident = ID_NUMBER;
+}
+
+void SampleFreqSet(u32 freq)
+{
+    struct SoundInfo *soundInfo = SOUND_INFO_PTR;
+
+    freq = (freq & 0xF0000) >> 16;
+    soundInfo->freq = freq;
+    soundInfo->pcmSamplesPerVBlank = gPcmSamplesPerVBlankTable[freq - 1];
+    soundInfo->pcmDmaPeriod = PCM_DMA_BUF_SIZE / soundInfo->pcmSamplesPerVBlank;
+
+    // LCD refresh rate 59.7275Hz
+    soundInfo->pcmFreq = (597275 * soundInfo->pcmSamplesPerVBlank + 5000) / 10000;
+
+    // CPU frequency 16.78Mhz
+    soundInfo->divFreq = (16777216 / soundInfo->pcmFreq + 1) >> 1;
+
+    // Turn off timer 0.
+    REG_TM0CNT_H = 0;
+
+    // cycles per LCD fresh 280896
+    REG_TM0CNT_L = -(280896 / soundInfo->pcmSamplesPerVBlank);
+
+    m4aSoundVSyncOn();
+
+    while (*(vu8 *)REG_ADDR_VCOUNT == 159)
+        ;
+
+    while (*(vu8 *)REG_ADDR_VCOUNT != 159)
+        ;
+
+    REG_TM0CNT_H = TIMER_ENABLE | TIMER_1CLK;
+}
+
+void m4aSoundMode(u32 mode)
+{
+    struct SoundInfo *soundInfo = SOUND_INFO_PTR;
+    u32 temp;
+
+    if (soundInfo->ident != ID_NUMBER)
+        return;
+
+    soundInfo->ident++;
+
+    temp = mode & (SOUND_MODE_REVERB_SET | SOUND_MODE_REVERB_VAL);
+
+    if (temp)
+        soundInfo->reverb = temp & SOUND_MODE_REVERB_VAL;
+
+    temp = mode & SOUND_MODE_MAXCHN;
+
+    if (temp)
+    {
+        struct SoundChannel *chan;
+
+        soundInfo->maxChans = temp >> SOUND_MODE_MAXCHN_SHIFT;
+
+        temp = MAX_DIRECTSOUND_CHANNELS;
+        chan = &soundInfo->chans[0];
+
+        while (temp != 0)
+        {
+            chan->status = 0;
+            temp--;
+            chan++;
+        }
+    }
+
+    temp = mode & SOUND_MODE_MASVOL;
+
+    if (temp)
+        soundInfo->masterVolume = temp >> SOUND_MODE_MASVOL_SHIFT;
+
+    temp = mode & SOUND_MODE_DA_BIT;
+
+    if (temp)
+    {
+        temp = (temp & 0x300000) >> 14;
+        REG_SOUNDBIAS_H = (REG_SOUNDBIAS_H & 0x3F) | temp;
+    }
+
+    temp = mode & SOUND_MODE_FREQ;
+
+    if (temp)
+    {
+        m4aSoundVSyncOff();
+        SampleFreqSet(temp);
+    }
+
+    soundInfo->ident = ID_NUMBER;
+}
+
+void SoundClear(void)
+{
+    struct SoundInfo *soundInfo = SOUND_INFO_PTR;
+    s32 i;
+    void *chan;
+
+    if (soundInfo->ident != ID_NUMBER)
+        return;
+
+    soundInfo->ident++;
+
+    i = MAX_DIRECTSOUND_CHANNELS;
+    chan = &soundInfo->chans[0];
+
+    while (i > 0)
+    {
+        ((struct SoundChannel *)chan)->status = 0;
+        i--;
+        chan = (void *)((s32)chan + sizeof(struct SoundChannel));
+    }
+
+    chan = soundInfo->cgbChans;
+
+    if (chan)
+    {
+        i = 1;
+
+        while (i <= 4)
+        {
+            soundInfo->CgbOscOff(i);
+            ((struct CgbChannel *)chan)->sf = 0;
+            i++;
+            chan = (void *)((s32)chan + sizeof(struct CgbChannel));
+        }
+    }
+
+    soundInfo->ident = ID_NUMBER;
+}
+
+void m4aSoundVSyncOff(void)
+{
+    struct SoundInfo *soundInfo = SOUND_INFO_PTR;
+
+    if (soundInfo->ident >= ID_NUMBER && soundInfo->ident <= ID_NUMBER + 1)
+    {
+        soundInfo->ident += 10;
+
+        if (REG_DMA1CNT & (DMA_REPEAT << 16))
+            REG_DMA1CNT = ((DMA_ENABLE | DMA_START_NOW | DMA_32BIT | DMA_SRC_INC | DMA_DEST_FIXED) << 16) | 4;
+
+        if (REG_DMA2CNT & (DMA_REPEAT << 16))
+            REG_DMA2CNT = ((DMA_ENABLE | DMA_START_NOW | DMA_32BIT | DMA_SRC_INC | DMA_DEST_FIXED) << 16) | 4;
+
+        REG_DMA1CNT_H = DMA_32BIT;
+        REG_DMA2CNT_H = DMA_32BIT;
+
+        CpuFill32(0, soundInfo->pcmBuffer, sizeof(soundInfo->pcmBuffer));
+    }
+}
+
+void m4aSoundVSyncOn(void)
+{
+    struct SoundInfo *soundInfo = SOUND_INFO_PTR;
+    u32 ident = soundInfo->ident;
+
+    if (ident == ID_NUMBER)
+        return;
+
+    REG_DMA1CNT_H = DMA_ENABLE | DMA_START_SPECIAL | DMA_32BIT | DMA_REPEAT;
+    REG_DMA2CNT_H = DMA_ENABLE | DMA_START_SPECIAL | DMA_32BIT | DMA_REPEAT;
+
+    soundInfo->pcmDmaCounter = 0;
+    soundInfo->ident = ident - 10;
+}
+
+void MPlayOpen(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *tracks, u8 trackCount)
+{
+    struct SoundInfo *soundInfo;
+
+    if (trackCount == 0)
+        return;
+
+    if (trackCount > MAX_MUSICPLAYER_TRACKS)
+        trackCount = MAX_MUSICPLAYER_TRACKS;
+
+    soundInfo = SOUND_INFO_PTR;
+
+    if (soundInfo->ident != ID_NUMBER)
+        return;
+
+    soundInfo->ident++;
+
+    Clear64byte(mplayInfo);
+
+    mplayInfo->tracks = tracks;
+    mplayInfo->trackCount = trackCount;
+    mplayInfo->status = MUSICPLAYER_STATUS_PAUSE;
+
+    while (trackCount != 0)
+    {
+        tracks->flags = 0;
+        trackCount--;
+        tracks++;
+    }
+
+    if (soundInfo->func != 0)
+    {
+        mplayInfo->func = soundInfo->func;
+        mplayInfo->intp = soundInfo->intp;
+        soundInfo->func = 0;
+    }
+
+    soundInfo->intp = (u32)mplayInfo;
+    soundInfo->func = (u32)MPlayMain;
+    soundInfo->ident = ID_NUMBER;
+    mplayInfo->ident = ID_NUMBER;
+}
+
+void MPlayStart(struct MusicPlayerInfo *mplayInfo, struct SongHeader *songHeader)
+{
+    s32 i;
+    u8 unk_B;
+    struct MusicPlayerTrack *track;
+
+    if (mplayInfo->ident != ID_NUMBER)
+        return;
+
+    unk_B = mplayInfo->unk_B;
+
+    if (!unk_B
+        || ((!mplayInfo->songHeader || !(mplayInfo->tracks[0].flags & MPT_FLG_START))
+            && ((mplayInfo->status & MUSICPLAYER_STATUS_TRACK) == 0
+                || (mplayInfo->status & MUSICPLAYER_STATUS_PAUSE)))
+        || (mplayInfo->priority <= songHeader->priority))
+    {
+        mplayInfo->ident++;
+        mplayInfo->status = 0;
+        mplayInfo->songHeader = songHeader;
+        mplayInfo->tone = songHeader->tone;
+        mplayInfo->priority = songHeader->priority;
+        mplayInfo->clock = 0;
+        mplayInfo->tempoD = 150;
+        mplayInfo->tempoI = 150;
+        mplayInfo->tempoU = 0x100;
+        mplayInfo->tempoC = 0;
+        mplayInfo->fadeOI = 0;
+
+        i = 0;
+        track = mplayInfo->tracks;
+
+        while (i < songHeader->trackCount && i < mplayInfo->trackCount)
+        {
+            TrackStop(mplayInfo, track);
+            track->flags = MPT_FLG_EXIST | MPT_FLG_START;
+            track->chan = 0;
+            track->cmdPtr = songHeader->part[i];
+            i++;
+            track++;
+        }
+
+        while (i < mplayInfo->trackCount)
+        {
+            TrackStop(mplayInfo, track);
+            track->flags = 0;
+            i++;
+            track++;
+        }
+
+        if (songHeader->reverb & 0x80)
+            m4aSoundMode(songHeader->reverb);
+
+        mplayInfo->ident = ID_NUMBER;
+    }
+}
+
+void m4aMPlayStop(struct MusicPlayerInfo *mplayInfo)
+{
+    s32 i;
+    struct MusicPlayerTrack *track;
+
+    if (mplayInfo->ident != ID_NUMBER)
+        return;
+
+    mplayInfo->ident++;
+    mplayInfo->status |= MUSICPLAYER_STATUS_PAUSE;
+
+    i = mplayInfo->trackCount;
+    track = mplayInfo->tracks;
+
+    while (i > 0)
+    {
+        TrackStop(mplayInfo, track);
+        i--;
+        track++;
+    }
+
+    mplayInfo->ident = ID_NUMBER;
+}
+
+void FadeOutBody(struct MusicPlayerInfo *mplayInfo)
+{
+    s32 i;
+    struct MusicPlayerTrack *track;
+    u16 fadeOI = mplayInfo->fadeOI;
+    register u32 temp asm("r3");
+    register u16 mask asm("r2");
+
+    if (fadeOI == 0)
+        return;
+
+    mplayInfo->fadeOC--;
+
+    temp = 0xFFFF;
+    mask = temp;
+
+    if (mplayInfo->fadeOC != 0)
+        return;
+
+    mplayInfo->fadeOC = fadeOI;
+
+    if (mplayInfo->fadeOV & FADE_IN)
+    {
+        mplayInfo->fadeOV += (4 << FADE_VOL_SHIFT);
+
+        if ((u16)(mplayInfo->fadeOV & mask) >= (64 << FADE_VOL_SHIFT))
+        {
+            mplayInfo->fadeOV = (64 << FADE_VOL_SHIFT);
+            mplayInfo->fadeOI = 0;
+        }
+    }
+    else
+    {
+        mplayInfo->fadeOV -= (4 << FADE_VOL_SHIFT);
+
+        if ((s16)(mplayInfo->fadeOV & mask) <= 0)
+        {
+            i = mplayInfo->trackCount;
+            track = mplayInfo->tracks;
+
+            while (i > 0)
+            {
+                register u32 fadeOV asm("r7");
+                u32 val;
+
+                TrackStop(mplayInfo, track);
+
+                val = TEMPORARY_FADE;
+                fadeOV = mplayInfo->fadeOV;
+                val &= fadeOV;
+
+                if (!val)
+                    track->flags = 0;
+
+                i--;
+                track++;
+            }
+
+            if (mplayInfo->fadeOV & TEMPORARY_FADE)
+                mplayInfo->status |= MUSICPLAYER_STATUS_PAUSE;
+            else
+                mplayInfo->status = MUSICPLAYER_STATUS_PAUSE;
+
+            mplayInfo->fadeOI = 0;
+            return;
+        }
+    }
+
+    i = mplayInfo->trackCount;
+    track = mplayInfo->tracks;
+
+    while (i > 0)
+    {
+        if (track->flags & MPT_FLG_EXIST)
+        {
+            track->volX = (mplayInfo->fadeOV >> FADE_VOL_SHIFT);
+            track->flags |= MPT_FLG_VOLCHG;
+        }
+
+        i--;
+        track++;
+    }
+}
+
+void TrkVolPitSet(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    if (track->flags & MPT_FLG_VOLSET)
+    {
+        s32 x;
+        s32 y;
+
+        x = (u32)(track->vol * track->volX) >> 5;
+
+        if (track->modT == 1)
+            x = (u32)(x * (track->modM + 128)) >> 7;
+
+        y = 2 * track->pan + track->panX;
+
+        if (track->modT == 2)
+            y += track->modM;
+
+        if (y < -128)
+            y = -128;
+        else if (y > 127)
+            y = 127;
+
+        track->volMR = (u32)((y + 128) * x) >> 8;
+        track->volML = (u32)((127 - y) * x) >> 8;
+    }
+
+    if (track->flags & MPT_FLG_PITSET)
+    {
+        s32 bend = track->bend * track->bendRange;
+        register s32 x asm("r1") = track->tune;
+        x += bend;
+        x *= 4;
+        x += (track->keyShift << 8);
+        x += (track->keyShiftX << 8);
+        x += track->pitX;
+
+        if (track->modT == 0)
+            x += 16 * track->modM;
+
+        track->keyM = x >> 8;
+        track->pitM = x;
+    }
+
+    track->flags &= ~(MPT_FLG_PITSET | MPT_FLG_VOLSET);
+}
+
+u32 MidiKeyToCgbFreq(u8 chanNum, u8 key, u8 fineAdjust)
+{
+    if (chanNum == 4)
+    {
+        if (key <= 20)
+        {
+            key = 0;
+        }
+        else
+        {
+            key -= 21;
+            if (key > 59)
+                key = 59;
+        }
+
+        return gNoiseTable[key];
+    }
+    else
+    {
+        s32 val1;
+        s32 val2;
+
+        if (key <= 35)
+        {
+            fineAdjust = 0;
+            key = 0;
+        }
+        else
+        {
+            key -= 36;
+            if (key > 130)
+            {
+                key = 130;
+                fineAdjust = 255;
+            }
+        }
+
+        val1 = gCgbScaleTable[key];
+        val1 = gCgbFreqTable[val1 & 0xF] >> (val1 >> 4);
+
+        val2 = gCgbScaleTable[key + 1];
+        val2 = gCgbFreqTable[val2 & 0xF] >> (val2 >> 4);
+
+        return val1 + ((fineAdjust * (val2 - val1)) >> 8) + 2048;
+    }
+}
+
+void CgbOscOff(u8 chanNum)
+{
+    switch (chanNum)
+    {
+    case 1:
+        REG_NR12 = 8;
+        REG_NR14 = 0x80;
+        break;
+    case 2:
+        REG_NR22 = 8;
+        REG_NR24 = 0x80;
+        break;
+    case 3:
+        REG_NR30 = 0;
+        break;
+    default:
+        REG_NR42 = 8;
+        REG_NR44 = 0x80;
+    }
+}
+
+static inline int CgbPan(struct CgbChannel *chan)
+{
+    u32 rightVolume = chan->rightVolume;
+    u32 leftVolume = chan->leftVolume;
+
+    if ((rightVolume = (u8)rightVolume) >= (leftVolume = (u8)leftVolume))
+    {
+        if (rightVolume / 2 >= leftVolume)
+        {
+            chan->pan = 0x0F;
+            return 1;
+        }
+    }
+    else
+    {
+        if (leftVolume / 2 >= rightVolume)
+        {
+            chan->pan = 0xF0;
+            return 1;
+        }
+    }
+
+    return 0;
+}
+#ifndef NONMATCHING
+NAKED
+#endif
+void CgbModVol(struct CgbChannel *chan)
+{
+#ifdef NONMATCHING
+    struct SoundInfo *soundInfo = SOUND_INFO_PTR;
+
+    if ((soundInfo->mode & 1) || !CgbPan(chan))
+    {
+        chan->pan = 0xFF;
+        chan->eg = (u32)(chan->rightVolume + chan->leftVolume) >> 4;
+    }
+    else
+    {
+        // Force chan->rightVolume and chan->leftVolume to be read from memory again,
+        // even though there is no reason to do so.
+        // The command line option "-fno-gcse" achieves the same result as this.
+        asm("" : : : "memory");
+
+        chan->eg = (u32)(chan->rightVolume + chan->leftVolume) >> 4;
+        if (chan->eg > 15)
+            chan->eg = 15;
+    }
+
+    chan->sg = (chan->eg * chan->su + 15) >> 4;
+    chan->pan &= chan->panMask;
+#else
+    asm_unified("\tpush {r4,lr}\n"
+        "\tadds r1, r0, 0\n"
+        "\tldrb r0, [r1, 0x2]\n"
+        "\tlsls r2, r0, 24\n"
+        "\tlsrs r4, r2, 24\n"
+        "\tldrb r3, [r1, 0x3]\n"
+        "\tlsls r0, r3, 24\n"
+        "\tlsrs r3, r0, 24\n"
+        "\tcmp r4, r3\n"
+        "\tbcc _080AFA94\n"
+        "\tlsrs r0, r2, 25\n"
+        "\tcmp r0, r3\n"
+        "\tbcc _080AFAA0\n"
+        "\tmovs r0, 0xF\n"
+        "\tstrb r0, [r1, 0x1B]\n"
+        "\tb _080AFAAE\n"
+        "_080AFA94:\n"
+        "\tlsrs r0, 25\n"
+        "\tcmp r0, r4\n"
+        "\tbcc _080AFAA0\n"
+        "\tmovs r0, 0xF0\n"
+        "\tstrb r0, [r1, 0x1B]\n"
+        "\tb _080AFAAE\n"
+        "_080AFAA0:\n"
+        "\tmovs r0, 0xFF\n"
+        "\tstrb r0, [r1, 0x1B]\n"
+        "\tldrb r2, [r1, 0x3]\n"
+        "\tldrb r3, [r1, 0x2]\n"
+        "\tadds r0, r2, r3\n"
+        "\tlsrs r0, 4\n"
+        "\tb _080AFABE\n"
+        "_080AFAAE:\n"
+        "\tldrb r2, [r1, 0x3]\n"
+        "\tldrb r3, [r1, 0x2]\n"
+        "\tadds r0, r2, r3\n"
+        "\tlsrs r0, 4\n"
+        "\tstrb r0, [r1, 0xA]\n"
+        "\tcmp r0, 0xF\n"
+        "\tbls _080AFAC0\n"
+        "\tmovs r0, 0xF\n"
+        "_080AFABE:\n"
+        "\tstrb r0, [r1, 0xA]\n"
+        "_080AFAC0:\n"
+        "\tldrb r2, [r1, 0x6]\n"
+        "\tldrb r3, [r1, 0xA]\n"
+        "\tadds r0, r2, 0\n"
+        "\tmuls r0, r3\n"
+        "\tadds r0, 0xF\n"
+        "\tasrs r0, 4\n"
+        "\tstrb r0, [r1, 0x19]\n"
+        "\tldrb r0, [r1, 0x1C]\n"
+        "\tldrb r2, [r1, 0x1B]\n"
+        "\tands r0, r2\n"
+        "\tstrb r0, [r1, 0x1B]\n"
+        "\tpop {r4}\n"
+        "\tpop {r0}\n"
+        "\tbx r0\n");
+#endif
+}
\ No newline at end of file
diff --git a/src/m4a_4.c b/src/m4a_4.c
new file mode 100644
index 0000000..595ea5a
--- /dev/null
+++ b/src/m4a_4.c
@@ -0,0 +1,384 @@
+#include "gba/m4a_internal.h"
+
+void m4aMPlayTempoControl(struct MusicPlayerInfo *mplayInfo, u16 tempo)
+{
+    if (mplayInfo->ident == ID_NUMBER)
+    {
+        mplayInfo->ident++;
+        mplayInfo->tempoU = tempo;
+        mplayInfo->tempoI = (mplayInfo->tempoD * mplayInfo->tempoU) >> 8;
+        mplayInfo->ident = ID_NUMBER;
+    }
+}
+
+void m4aMPlayVolumeControl(struct MusicPlayerInfo *mplayInfo, u16 trackBits, u16 volume)
+{
+    s32 i;
+    u32 bit;
+    struct MusicPlayerTrack *track;
+
+    if (mplayInfo->ident != ID_NUMBER)
+        return;
+
+    mplayInfo->ident++;
+
+    i = mplayInfo->trackCount;
+    track = mplayInfo->tracks;
+    bit = 1;
+
+    while (i > 0)
+    {
+        if (trackBits & bit)
+        {
+            if (track->flags & MPT_FLG_EXIST)
+            {
+                track->volX = volume / 4;
+                track->flags |= MPT_FLG_VOLCHG;
+            }
+        }
+
+        i--;
+        track++;
+        bit <<= 1;
+    }
+
+    mplayInfo->ident = ID_NUMBER;
+}
+
+void m4aMPlayPitchControl(struct MusicPlayerInfo *mplayInfo, u16 trackBits, s16 pitch)
+{
+    s32 i;
+    u32 bit;
+    struct MusicPlayerTrack *track;
+
+    if (mplayInfo->ident != ID_NUMBER)
+        return;
+
+    mplayInfo->ident++;
+
+    i = mplayInfo->trackCount;
+    track = mplayInfo->tracks;
+    bit = 1;
+
+    while (i > 0)
+    {
+        if (trackBits & bit)
+        {
+            if (track->flags & MPT_FLG_EXIST)
+            {
+                track->keyShiftX = pitch >> 8;
+                track->pitX = pitch;
+                track->flags |= MPT_FLG_PITCHG;
+            }
+        }
+
+        i--;
+        track++;
+        bit <<= 1;
+    }
+
+    mplayInfo->ident = ID_NUMBER;
+}
+
+void m4aMPlayPanpotControl(struct MusicPlayerInfo *mplayInfo, u16 trackBits, s8 pan)
+{
+    s32 i;
+    u32 bit;
+    struct MusicPlayerTrack *track;
+
+    if (mplayInfo->ident != ID_NUMBER)
+        return;
+
+    mplayInfo->ident++;
+
+    i = mplayInfo->trackCount;
+    track = mplayInfo->tracks;
+    bit = 1;
+
+    while (i > 0)
+    {
+        if (trackBits & bit)
+        {
+            if (track->flags & MPT_FLG_EXIST)
+            {
+                track->panX = pan;
+                track->flags |= MPT_FLG_VOLCHG;
+            }
+        }
+
+        i--;
+        track++;
+        bit <<= 1;
+    }
+
+    mplayInfo->ident = ID_NUMBER;
+}
+
+void ClearModM(struct MusicPlayerTrack *track)
+{
+    track->lfoSpeedC = 0;
+    track->modM = 0;
+
+    if (track->modT == 0)
+        track->flags |= MPT_FLG_PITCHG;
+    else
+        track->flags |= MPT_FLG_VOLCHG;
+}
+
+void m4aMPlayModDepthSet(struct MusicPlayerInfo *mplayInfo, u16 trackBits, u8 modDepth)
+{
+    s32 i;
+    u32 bit;
+    struct MusicPlayerTrack *track;
+
+    if (mplayInfo->ident != ID_NUMBER)
+        return;
+
+    mplayInfo->ident++;
+
+    i = mplayInfo->trackCount;
+    track = mplayInfo->tracks;
+    bit = 1;
+
+    while (i > 0)
+    {
+        if (trackBits & bit)
+        {
+            if (track->flags & MPT_FLG_EXIST)
+            {
+                track->mod = modDepth;
+
+                if (!track->mod)
+                    ClearModM(track);
+            }
+        }
+
+        i--;
+        track++;
+        bit <<= 1;
+    }
+
+    mplayInfo->ident = ID_NUMBER;
+}
+
+void m4aMPlayLFOSpeedSet(struct MusicPlayerInfo *mplayInfo, u16 trackBits, u8 lfoSpeed)
+{
+    s32 i;
+    u32 bit;
+    struct MusicPlayerTrack *track;
+
+    if (mplayInfo->ident != ID_NUMBER)
+        return;
+
+    mplayInfo->ident++;
+
+    i = mplayInfo->trackCount;
+    track = mplayInfo->tracks;
+    bit = 1;
+
+    while (i > 0)
+    {
+        if (trackBits & bit)
+        {
+            if (track->flags & MPT_FLG_EXIST)
+            {
+                track->lfoSpeed = lfoSpeed;
+
+                if (!track->lfoSpeed)
+                    ClearModM(track);
+            }
+        }
+
+        i--;
+        track++;
+        bit <<= 1;
+    }
+
+    mplayInfo->ident = ID_NUMBER;
+}
+
+#define MEMACC_COND_JUMP(cond) \
+if (cond)                      \
+    goto cond_true;            \
+else                           \
+    goto cond_false;           \
+
+void ply_memacc(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    u32 op;
+    u8 *addr;
+    u8 data;
+
+    op = *track->cmdPtr;
+    track->cmdPtr++;
+
+    addr = mplayInfo->memAccArea + *track->cmdPtr;
+    track->cmdPtr++;
+
+    data = *track->cmdPtr;
+    track->cmdPtr++;
+
+    switch (op)
+    {
+    case 0:
+        *addr = data;
+        return;
+    case 1:
+        *addr += data;
+        return;
+    case 2:
+        *addr -= data;
+        return;
+    case 3:
+        *addr = mplayInfo->memAccArea[data];
+        return;
+    case 4:
+        *addr += mplayInfo->memAccArea[data];
+        return;
+    case 5:
+        *addr -= mplayInfo->memAccArea[data];
+        return;
+    case 6:
+        MEMACC_COND_JUMP(*addr == data)
+        return;
+    case 7:
+        MEMACC_COND_JUMP(*addr != data)
+        return;
+    case 8:
+        MEMACC_COND_JUMP(*addr > data)
+        return;
+    case 9:
+        MEMACC_COND_JUMP(*addr >= data)
+        return;
+    case 10:
+        MEMACC_COND_JUMP(*addr <= data)
+        return;
+    case 11:
+        MEMACC_COND_JUMP(*addr < data)
+        return;
+    case 12:
+        MEMACC_COND_JUMP(*addr == mplayInfo->memAccArea[data])
+        return;
+    case 13:
+        MEMACC_COND_JUMP(*addr != mplayInfo->memAccArea[data])
+        return;
+    case 14:
+        MEMACC_COND_JUMP(*addr > mplayInfo->memAccArea[data])
+        return;
+    case 15:
+        MEMACC_COND_JUMP(*addr >= mplayInfo->memAccArea[data])
+        return;
+    case 16:
+        MEMACC_COND_JUMP(*addr <= mplayInfo->memAccArea[data])
+        return;
+    case 17:
+        MEMACC_COND_JUMP(*addr < mplayInfo->memAccArea[data])
+        return;
+    default:
+        return;
+    }
+
+cond_true:
+    {
+        void (*func)(struct MusicPlayerInfo *, struct MusicPlayerTrack *) = *(&gMPlayJumpTable[1]);
+        func(mplayInfo, track);
+        return;
+    }
+
+cond_false:
+    track->cmdPtr += 4;
+}
+
+void ply_xcmd(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    u32 n = *track->cmdPtr;
+    track->cmdPtr++;
+
+    gXcmdTable[n](mplayInfo, track);
+}
+
+void ply_xxx(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    void (*func)(struct MusicPlayerInfo *, struct MusicPlayerTrack *) = *(&gMPlayJumpTable[0]);
+    func(mplayInfo, track);
+}
+
+#define READ_XCMD_BYTE(var, n)       \
+{                                    \
+    u32 byte = track->cmdPtr[(n)]; \
+    byte <<= n * 8;                  \
+    (var) &= ~(0xFF << (n * 8));     \
+    (var) |= byte;                   \
+}
+
+void ply_xwave(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    u32 wav;
+
+    READ_XCMD_BYTE(wav, 0) // UB: uninitialized variable
+    READ_XCMD_BYTE(wav, 1)
+    READ_XCMD_BYTE(wav, 2)
+    READ_XCMD_BYTE(wav, 3)
+
+    track->tone.wav = (struct WaveData *)wav;
+    track->cmdPtr += 4;
+}
+
+void ply_xtype(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->tone.type = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void ply_xatta(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->tone.attack = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void ply_xdeca(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->tone.decay = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void ply_xsust(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->tone.sustain = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void ply_xrele(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->tone.release = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void ply_xiecv(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->echoVolume = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void ply_xiecl(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->echoLength = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void ply_xleng(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->tone.length = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void ply_xswee(struct MusicPlayerInfo *mplayInfo, struct MusicPlayerTrack *track)
+{
+    track->tone.pan_sweep = *track->cmdPtr;
+    track->cmdPtr++;
+}
+
+void DummyFunc()
+{
+    ;
+}
diff --git a/src/m4a_tables.c b/src/m4a_tables.c
new file mode 100644
index 0000000..fd289a6
--- /dev/null
+++ b/src/m4a_tables.c
@@ -0,0 +1,223 @@
+#include "gba/m4a_internal.h"
+
+// Some of these functions have different signatures, so we need to make this
+// an array of void pointers or a struct. It's simpler to just make it an array
+// for now.
+void * const gMPlayJumpTableTemplate[] =
+{
+    ply_fine,
+    ply_goto,
+    ply_patt,
+    ply_pend,
+    ply_rept,
+    ply_fine,
+    ply_fine,
+    ply_fine,
+    ply_fine,
+    ply_prio,
+    ply_tempo,
+    ply_keysh,
+    ply_voice,
+    ply_vol,
+    ply_pan,
+    ply_bend,
+    ply_bendr,
+    ply_lfos,
+    ply_lfodl,
+    ply_mod,
+    ply_modt,
+    ply_fine,
+    ply_fine,
+    ply_tune,
+    ply_fine,
+    ply_fine,
+    ply_fine,
+    ply_port,
+    ply_fine,
+    ply_endtie,
+    SampleFreqSet,
+    TrackStop,
+    FadeOutBody,
+    TrkVolPitSet,
+    RealClearChain,
+    SoundMainBTM,
+};
+
+const u8 gScaleTable[] =
+{
+    0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB,
+    0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB,
+    0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB,
+    0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB,
+    0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB,
+    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B,
+    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B,
+    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B,
+    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B,
+    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B,
+    0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B,
+    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B,
+    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B,
+};
+
+const u32 gFreqTable[] =
+{
+    2147483648u,
+    2275179671u,
+    2410468894u,
+    2553802834u,
+    2705659852u,
+    2866546760u,
+    3037000500u,
+    3217589947u,
+    3408917802u,
+    3611622603u,
+    3826380858u,
+    4053909305u,
+};
+
+const u16 gPcmSamplesPerVBlankTable[] =
+{
+    96,
+    132,
+    176,
+    224,
+    264,
+    304,
+    352,
+    448,
+    528,
+    608,
+    672,
+    704,
+};
+
+const u8 gCgbScaleTable[] =
+{
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B,
+    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B,
+    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B,
+    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+    0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B,
+    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B,
+    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B,
+    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B,
+    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B,
+    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B,
+    0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB,
+};
+
+const s16 gCgbFreqTable[] =
+{
+    -2004,
+    -1891,
+    -1785,
+    -1685,
+    -1591,
+    -1501,
+    -1417,
+    -1337,
+    -1262,
+    -1192,
+    -1125,
+    -1062,
+};
+
+const u8 gNoiseTable[] =
+{
+    0xD7, 0xD6, 0xD5, 0xD4,
+    0xC7, 0xC6, 0xC5, 0xC4,
+    0xB7, 0xB6, 0xB5, 0xB4,
+    0xA7, 0xA6, 0xA5, 0xA4,
+    0x97, 0x96, 0x95, 0x94,
+    0x87, 0x86, 0x85, 0x84,
+    0x77, 0x76, 0x75, 0x74,
+    0x67, 0x66, 0x65, 0x64,
+    0x57, 0x56, 0x55, 0x54,
+    0x47, 0x46, 0x45, 0x44,
+    0x37, 0x36, 0x35, 0x34,
+    0x27, 0x26, 0x25, 0x24,
+    0x17, 0x16, 0x15, 0x14,
+    0x07, 0x06, 0x05, 0x04,
+    0x03, 0x02, 0x01, 0x00,
+};
+
+const u8 gCgb3Vol[] =
+{
+    0x00, 0x00,
+    0x60, 0x60, 0x60, 0x60,
+    0x40, 0x40, 0x40, 0x40,
+    0x80, 0x80, 0x80, 0x80,
+    0x20, 0x20,
+};
+
+const u8 gClockTable[] =
+{
+    0x00,
+    0x01,
+    0x02,
+    0x03,
+    0x04,
+    0x05,
+    0x06,
+    0x07,
+    0x08,
+    0x09,
+    0x0A,
+    0x0B,
+    0x0C,
+    0x0D,
+    0x0E,
+    0x0F,
+    0x10,
+    0x11,
+    0x12,
+    0x13,
+    0x14,
+    0x15,
+    0x16,
+    0x17,
+    0x18,
+    0x1C,
+    0x1E,
+    0x20,
+    0x24,
+    0x28,
+    0x2A,
+    0x2C,
+    0x30,
+    0x34,
+    0x36,
+    0x38,
+    0x3C,
+    0x40,
+    0x42,
+    0x44,
+    0x48,
+    0x4C,
+    0x4E,
+    0x50,
+    0x54,
+    0x58,
+    0x5A,
+    0x5C,
+    0x60,
+};
+
+const XcmdFunc gXcmdTable[] =
+{
+    ply_xxx,
+    ply_xwave,
+    ply_xtype,
+    ply_xxx,
+    ply_xatta,
+    ply_xdeca,
+    ply_xsust,
+    ply_xrele,
+    ply_xiecv,
+    ply_xiecl,
+    ply_xleng,
+    ply_xswee
+};
diff --git a/src/memory.c b/src/memory.c
new file mode 100644
index 0000000..05c89a2
--- /dev/null
+++ b/src/memory.c
@@ -0,0 +1,145 @@
+#include "global.h"
+#include "memory.h"
+
+extern struct HeapFreeListElement gMainHeapFreeList[32];
+extern u8 gMainHeap[HEAP_SIZE];
+extern u32 gHeapCount;
+extern struct HeapDescriptor gMainHeapDescriptor;
+extern struct HeapDescriptor *gHeapDescriptorList[8];
+
+extern void CpuClear(u32 *dest, s32 size);
+
+void InitHeapInternal(void);
+
+void InitHeap(void)
+{
+    InitHeapInternal();
+}
+
+void MemoryClear8(u8 *dest, s32 size)
+{
+    while (size > 0)
+    {
+        size -= 1;
+        *dest++ = 0;
+    }
+}
+
+void MemoryClear16(u16 *dest, s32 size)
+{
+    while (size > 0)
+    {
+        size -= 2;
+        *dest++ = 0;
+    }
+}
+void MemoryClear32(u32 *dest, s32 size)
+{
+    CpuClear(dest, size);
+}
+
+void MemoryFill8(u8 *dest, u8 value, s32 size)
+{
+    while (size > 0)
+    {
+        size -= 1;
+        *dest++ = value;
+    }
+}
+
+void MemoryFill16(u16 *dest, u16 value, s32 size)
+{
+    while (size > 0)
+    {
+        size -= 2;
+        *dest++ = value;
+    }
+}
+
+void MemoryFill32(u32 *dest, u32 value, s32 size)
+{
+    while (size > 0)
+    {
+        size -= 4;
+        *dest++ = value;
+    }
+}
+
+void MemoryCopy8(u8 *dest, u8 *src, s32 size)
+{
+    while (size > 0)
+    {
+        size -= 1;
+        *dest++ = *src++;
+    }
+}
+
+void MemoryCopy16(u16 *dest, u16 *src, s32 size)
+{
+    while (size > 0)
+    {
+        size -= 2;
+        *dest++ = *src++;
+    }
+}
+
+void MemoryCopy32(u32 *dest, u32 *src, s32 size)
+{
+    while (size > 0)
+    {
+        size -= 4;
+        *dest++ = *src++;
+    }
+}
+
+void InitHeapInternal(void)
+{
+    struct HeapSettings settings;
+
+    settings.start = gMainHeap;
+    settings.size = HEAP_SIZE;
+    gHeapCount = 0;
+    DoInitHeap(&gMainHeapDescriptor, &settings, gMainHeapFreeList, sizeof(gMainHeapFreeList) / sizeof(struct HeapFreeListElement));
+}
+
+void DoInitHeap(struct HeapDescriptor *descriptor, struct HeapSettings *settings, struct HeapFreeListElement *freeList, u32 freeListLength)
+{
+    u32 aligned_size;
+
+    aligned_size = settings->size & 0xFFFFFFFC;
+
+    gHeapDescriptorList[gHeapCount++] = descriptor;
+
+    descriptor->start = settings->start;
+    descriptor->size = aligned_size;
+    descriptor->unk0 = 2;
+    descriptor->parentHeap = NULL;
+    descriptor->freeList = freeList;
+    descriptor->freeCount = 1;
+    descriptor->freeListLength = freeListLength;
+
+    freeList->unk_atb = 0;
+    freeList->atb = 0;
+    freeList->block.start = descriptor->start;
+    freeList->block.size = aligned_size;
+    freeList->block.allocatedSize = 0;
+    freeList->grp = 0;
+}
+
+void InitSubHeap(struct HeapDescriptor *parentHeap, struct HeapMemoryBlock *block, u32 freeListMax)
+{
+    u32 freeListSize;
+    u32 aligned_size;
+    u32 alignment;
+    struct HeapFreeListElement *freeList;
+    struct HeapSettings settings;
+
+    freeListSize = freeListMax * 3;
+    alignment = ~3;
+    freeListSize *= 8;
+    aligned_size = (block->size - freeListSize) & alignment;
+    freeList = (struct HeapFreeListElement *)block->start;
+    settings.start = &((u8 *)block->start)[freeListSize];
+    settings.size = aligned_size;
+    DoInitHeap(parentHeap, &settings, freeList, freeListMax);
+}
diff --git a/src/save.c b/src/save.c
new file mode 100644
index 0000000..5d39bfe
--- /dev/null
+++ b/src/save.c
@@ -0,0 +1,64 @@
+#include "global.h"
+
+extern u32 gUnknown_203B17C;
+extern u32 gUnknown_203B180;
+extern u32 *gUnknown_203B184;
+extern u32 gUnknown_202DE28;
+
+
+u32 sub_8011C1C(void)
+{
+    return gUnknown_203B17C;
+}
+
+void sub_8011C28(u32 in)
+{
+    gUnknown_203B17C = in;
+}
+
+u32 sub_8011C34(void)
+{
+    return gUnknown_202DE28;
+}
+
+void sub_8011C40(u32 in)
+{
+    gUnknown_202DE28 = in;
+}
+
+u32 sub_8011C4C(void)
+{
+    return gUnknown_203B180;
+}
+
+void CalculateChecksum(u8 *out, u32 size)
+{
+    u32 checksum = 0;
+    s32 i = size / 4;
+    if (i > 1)
+    {
+        u32 *ptr = (u32 *)&out[4];
+        --i;
+        do
+            checksum += *ptr++;
+        while (--i);
+    }
+    *(u32 *)out = checksum;
+}
+
+bool8 ValidateChecksum(u8 *in, u32 size)
+{
+    u32 checksum = 0;
+    s32 i = size / 4;
+    if (i > 1)
+	{
+        u32 *ptr = (u32 *)&in[4];
+        --i;
+        do
+            checksum += *ptr++;
+        while (--i);
+	}
+    if (*(u32 *)in != checksum)
+        return TRUE;
+    return FALSE;
+}
diff --git a/src/save1.c b/src/save1.c
new file mode 100644
index 0000000..b7de6c6
--- /dev/null
+++ b/src/save1.c
@@ -0,0 +1,13 @@
+#include "global.h"
+
+extern void MemoryFree(void *);
+
+extern u8 *gUnknown_203B194;
+
+void sub_80129FC()
+{
+    if (gUnknown_203B194) {
+        MemoryFree(gUnknown_203B194);
+        gUnknown_203B194 = NULL;
+    }
+}
diff --git a/src/sprite.c b/src/sprite.c
new file mode 100644
index 0000000..d741fce
--- /dev/null
+++ b/src/sprite.c
@@ -0,0 +1,10 @@
+#include "global.h"
+
+void ResetSprites(bool32);
+void SetSavingIconCoords(u32);  
+
+void InitSprites(void)
+{
+    ResetSprites(1);
+    SetSavingIconCoords(0);
+}
diff --git a/src/text.c b/src/text.c
new file mode 100644
index 0000000..9de996a
--- /dev/null
+++ b/src/text.c
@@ -0,0 +1,198 @@
+#include "global.h"
+#include "file_system.h"
+#include "code_800558C.h"
+#include "code_800B540.h"
+
+struct UnkTextStruct1 {
+    u8 fill00[4];
+    u16 unk04;
+    u8 fill06[2];
+    u16 unk08;
+    u8 fill04[0x3c];
+    u8 unk46;
+};
+
+struct UnkTextStruct2 {
+    u8 fill00[0x0c];
+    s16 unk0c;
+    u8 fill0e[2];
+    s16 unk10;
+    u8 fill12[0x06];
+};
+
+extern char gUnknown_3000E94[];
+
+EWRAM_DATA struct UnkTextStruct1 gUnknown_2027370[4];
+EWRAM_DATA u8 *gKanji[2];
+EWRAM_DATA u16 gUnknown_2027498;
+EWRAM_DATA u8 gUnknown_20274A5;
+EWRAM_DATA u32 gUnknown_20274AC;
+EWRAM_DATA vu32 gUnknown_20274B0;
+EWRAM_DATA u8 gUnknown_20274B4[0x3b00];
+EWRAM_DATA struct OpenedFile *gKanjiFiles[2];
+EWRAM_DATA struct UnkTextStruct2 gUnknown_202AFC0[4];
+EWRAM_DATA u32 gUnknown_202B020;
+EWRAM_DATA u32 gUnknown_202B024;
+EWRAM_DATA u32 gUnknown_202B028[2];
+EWRAM_DATA u32 gUnknown_202B030;
+EWRAM_DATA u8 gUnknown_202B034;
+EWRAM_DATA u16 gUnknown_202B038[2][32][32];
+
+u32 xxx_update_some_bg_tiles(u32 a0);
+void sub_8006438(const struct UnkTextStruct2 *a0, u8 a1, u8 a2, u32 *a3);
+void sub_8006554(void *a0, void *a1, void *a2, void *a3, u32 a4, const struct UnkTextStruct2 *a5, u8 a6, u32 a7, u32 *a8, u32 a9);
+void sub_800898C(void);
+void sub_80089AC(const struct UnkTextStruct2 *a0, void *a1);
+void sub_8009388(void);
+
+extern const struct UnkTextStruct2 gUnknown_80B857C[4];
+extern const char gUnknown_80B87B4[];
+extern const char gUnknown_80B87BC[];
+extern const struct FileArchive gUnknown_8300500;
+extern const u32 gUnknown_80B87C4[8];
+extern const u32 gUnknown_80B87E4[8];
+extern const u32 gUnknown_80B8804[4];
+
+void sub_8006218(void)
+{
+    int i;
+    int j;
+    int k;
+
+    gUnknown_20274AC = 0;
+    gKanjiFiles[0] = OpenFileAndGetFileDataPtr(gUnknown_80B87B4, &gUnknown_8300500);
+    gKanjiFiles[1] = OpenFileAndGetFileDataPtr(gUnknown_80B87BC, &gUnknown_8300500);
+    gKanji[0] = gKanjiFiles[0]->data;
+    gKanji[1] = gKanjiFiles[1]->data;
+    gUnknown_202B028[0] = 11;
+    gUnknown_202B028[1] = 12;
+    for (k = 0; k < 4; k++)
+    {
+        gUnknown_2027370[k].unk04 = 0;
+        gUnknown_2027370[k].unk08 = 0;
+        gUnknown_2027370[k].unk46 = 0;
+    }
+    gUnknown_2027498 = 0;
+    for (i = 0; i < 20; i++)
+    {
+        gUnknown_202B038[0][i][0] = 0xf279;
+        gUnknown_202B038[1][i][0] = 0xf27a;
+        for (j = 1; j < 32; j++)
+        {
+            gUnknown_202B038[0][i][j] = 0;
+            gUnknown_202B038[1][i][j] = 0xf27a;
+        }
+    }
+    gUnknown_202B034 = 1;
+    gUnknown_202B030 = 0x88888888;
+    gUnknown_203B078 = NULL;
+    gUnknown_20274A5 = 0;
+    gUnknown_202B020 = 1;
+    gUnknown_202B024 = 20;
+    xxx_update_some_bg_tiles(0);
+}
+
+u32 xxx_update_some_bg_tiles(u32 a0)
+{
+    u32 r5 = gUnknown_20274B0;
+    u32 *r4 = (u32 *)(VRAM + 0x4f40);
+    const u32 *r2;
+    gUnknown_20274B0 = a0;
+    if (a0 == 0 || a0 == 2)
+    {
+        sub_800CDA8(2);
+        r2 = gUnknown_80B87C4;
+    }
+    else
+    {
+        sub_800CDA8(1);
+        r2 = gUnknown_80B87E4;
+    }
+    gUnknown_202B030 = 0x88888888;
+    *r4++ = *r2++;
+    *r4++ = *r2++;
+    *r4++ = *r2++;
+    *r4++ = *r2++;
+    *r4++ = *r2++;
+    *r4++ = *r2++;
+    *r4++ = *r2++;
+    *r4++ = *r2++;
+    return r5;
+}
+
+u32 sub_80063B0(void)
+{
+    return gUnknown_20274B0;
+}
+
+u8 sub_80063BC(u8 a0)
+{
+    u8 retval = gUnknown_202B034;
+    gUnknown_202B034 = a0;
+    return retval;
+}
+
+void sub_80063CC(u32 a0)
+{
+    gUnknown_20274AC = a0;
+}
+
+void sub_80063D8(int a0)
+{
+    u32 retval;
+    if (a0 == 0)
+    {
+        gUnknown_20274B0;
+        retval = 0x88888888;
+    }
+    else
+    {
+        retval = (a0 & 0xf) | ((a0 & 0xf) << 4);
+        retval |= ((a0 & 0xf) << 8);
+        retval |= ((a0 & 0xf) << 12);
+        retval |= ((a0 & 0xf) << 16);
+        retval |= ((a0 & 0xf) << 20);
+        retval |= ((a0 & 0xf) << 24);
+        retval |= ((a0 & 0xf) << 28);
+    }
+    gUnknown_202B030 = retval;
+}
+
+void sub_800641C(void *a0, u8 a1, u8 a2)
+{
+    u32 r3 = 0;
+    sub_8006438(a0, a1, a2, &r3);
+}
+
+void sub_8006438(const struct UnkTextStruct2 *a0, u8 a1, u8 a2, u32 *a3)
+{
+    int i;
+    u32 r9 = 2;
+
+    if (a0 == NULL)
+        a0 = gUnknown_80B857C;
+    if (a2)
+        sub_8009388();
+    sub_800898C();
+    for (i = 0; i < 4; i++)
+    {
+        gUnknown_202AFC0[i] = a0[i];
+        if (a0[i].unk0c)
+        {
+            sub_8006554(gUnknown_2027370, (void *)VRAM, gUnknown_20274B4, gUnknown_202B038, gUnknown_80B8804[i], a0 + i, a1, r9, a3, 0);
+            sub_80089AC(a0 + i, a3);
+            r9 += a0[i].unk0c * a0[i].unk10;
+        }
+    }
+#ifdef NONMATCHING
+    gUnknown_203B078 = gUnknown_3000E94;
+    gUnknown_20274A5 = 1;
+#else
+    asm_unified("\tldr r2, =gUnknown_203B078\n"
+        "\tldr r0, =gUnknown_3000E94\n"
+        "\tldr r1, =gUnknown_20274A5\n"
+        "\tstr r0, [r2]\n"
+        "\tmovs r0, 0x1\n"
+        "\tstrb r0, [r1]");
+#endif
+}