diff --git a/asm/rom_header.inc b/asm/rom_header.inc
deleted file mode 100644
index 6730efae2..000000000
--- a/asm/rom_header.inc
+++ /dev/null
@@ -1,35 +0,0 @@
-	.global RomHeaderNintendoLogo
-RomHeaderNintendoLogo:
-	.space 156
-
-RomHeaderGameTitle:
-	.space 12
-
-	.global RomHeaderGameCode
-RomHeaderGameCode:
-	.space 4
-
-RomHeaderMakerCode:
-	.space 2
-
-RomHeaderMagic:
-	.byte 0
-
-RomHeaderMainUnitCode:
-	.byte 0
-
-RomHeaderDeviceType:
-	.byte 0
-
-RomHeaderReserved1:
-	.space 7
-
-	.global RomHeaderSoftwareVersion
-RomHeaderSoftwareVersion:
-	.byte 0
-
-RomHeaderChecksum:
-	.byte 0
-
-RomHeaderReserved2:
-	.space 2
diff --git a/include/crt0.h b/include/crt0.h
index 3121eeaed..a4a5c7f79 100644
--- a/include/crt0.h
+++ b/include/crt0.h
@@ -1,11 +1,6 @@
 #ifndef GUARD_CRT0_H
 #define GUARD_CRT0_H
 
-// Exported type declarations
-
-// Exported RAM declarations
-
-// Exported ROM declarations
 extern u32 IntrMain[];
 
 #endif //GUARD_CRT0_H
diff --git a/include/item.h b/include/item.h
index 87ff57bc7..ceca83bd5 100644
--- a/include/item.h
+++ b/include/item.h
@@ -29,6 +29,7 @@ struct BagPocket
     u8 capacity;
 };
 
+extern const struct Item gItems[];
 extern struct BagPocket gBagPockets[];
 
 void ApplyNewEncryptionKeyToBagItems(u32 newKey);
diff --git a/include/pokeball.h b/include/pokeball.h
index d88e80173..297788db1 100644
--- a/include/pokeball.h
+++ b/include/pokeball.h
@@ -26,6 +26,8 @@ enum {
     BALL_AFFINE_ANIM_4
 };
 
+extern const struct CompressedSpriteSheet gBallSpriteSheets[];
+extern const struct CompressedSpritePalette gBallSpritePalettes[];
 extern const struct SpriteTemplate gBallSpriteTemplates[];
 
 #define POKEBALL_PLAYER_SENDOUT     0xFF
diff --git a/include/pokemon_icon.h b/include/pokemon_icon.h
index 4731da90e..9b917c3bf 100644
--- a/include/pokemon_icon.h
+++ b/include/pokemon_icon.h
@@ -2,6 +2,8 @@
 #define GUARD_POKEMON_ICON_H
 
 extern const u8 gMonIconPaletteIndices[];
+extern const u8 *const gMonIconTable[];
+extern const struct SpritePalette gMonIconPaletteTable[];
 
 const u8 *GetMonIconTiles(u16 species, bool32);
 void TryLoadAllMonIconPalettesAtOffset(u16 offset);
diff --git a/ld_script.txt b/ld_script.txt
index e310bf717..cecb8f23c 100644
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -47,6 +47,8 @@ SECTIONS {
     .text :
     ALIGN(4)
     {
+        src/rom_header.o(.text);
+        src/rom_header_gf.o(.text.*);
         src/crt0.o(.text);
         src/main.o(.text);
         gflib/malloc.o(.text);
@@ -435,6 +437,8 @@ SECTIONS {
     .rodata :
     ALIGN(4)
     {
+        src/rom_header.o(.rodata);
+        src/rom_header_gf.o(.rodata);
         src/main.o(.rodata);
         gflib/bg.o(.rodata);
         gflib/window.o(.rodata);
diff --git a/ld_script_modern.txt b/ld_script_modern.txt
index c5c711bfd..ac62abe27 100644
--- a/ld_script_modern.txt
+++ b/ld_script_modern.txt
@@ -47,7 +47,7 @@ SECTIONS {
     .text :
     ALIGN(4)
     {
-        src/crt0.o(.text*);
+        src/rom_header.o(.text*);
         src/*.o(.text*);
         gflib/*.o(.text*);
         asm/*.o(.text*);
diff --git a/src/crt0.s b/src/crt0.s
index 672fc94f2..7c679c13b 100644
--- a/src/crt0.s
+++ b/src/crt0.s
@@ -1,108 +1,9 @@
-#include "constants/global.h"
 	.include "constants/gba_constants.inc"
 
 	.syntax unified
 
-	.global Start
-
-	.text
-
 	.arm
 
-Start: @ 8000000
-	b Init
-
-	.include "asm/rom_header.inc"
-
-@ 80000C0
-	.word 0
-
-	.global GPIOPortData
-GPIOPortData: @ 80000C4
-	.2byte 0
-
-	.global GPIOPortDirection
-GPIOPortDirection: @ 80000C6
-	.2byte 0
-
-	.global GPIOPortReadEnable
-GPIOPortReadEnable: @ 80000C8
-	.2byte 0
-
-@ 80000CA
-	.2byte 0
-
-@ 80000CC
-	.space 0x34
-
-	.4byte GAME_VERSION
-	.4byte GAME_LANGUAGE
-
-	.ascii "pokemon emerald version"
-	.space 9
-
-	.4byte gMonFrontPicTable
-	.4byte gMonBackPicTable
-	.4byte gMonPaletteTable
-	.4byte gMonShinyPaletteTable
-	.4byte gMonIconTable
-	.4byte gMonIconPaletteIndices
-	.4byte gMonIconPaletteTable
-	.4byte gSpeciesNames
-	.4byte gMoveNames
-	.4byte gDecorations
-
-	.4byte 0x00001270 @ offsetof(struct SaveBlock1, flags)
-	.4byte 0x0000139c @ offsetof(struct SaveBlock1, vars)
-	.4byte 0x00000018 @ offsetof(struct SaveBlock2, pokedex)
-	.4byte 0x00000988 @ offsetof(struct SaveBlock1, seen1)
-	.4byte 0x00003b24 @ offsetof(struct SaveBlock1, seen2)
-	.4byte 0x00000046 @ ?
-	.4byte 0x000008e4 @ ?
-	.4byte 0x000008ac @ ?
-	.4byte 0x00000182 @ NATIONAL_DEX_COUNT?
-
-	.byte 0x07, 0x0a, 0x0a, 0x0a, 0x0c, 0x0c, 0x06, 0x0c
-	.byte 0x06, 0x10, 0x12, 0x0c, 0x0f, 0x0b, 0x01, 0x08
-
-	.4byte 0x0000000c @ ?
-	.4byte 0x00000f2c @ sizeof(struct SaveBlock2)
-	.4byte 0x00003d88 @ sizeof(struct SaveBlock1)
-	.4byte 0x00000234 @ offsetof(struct SaveBlock1, playerPartyCount)
-	.4byte 0x00000238 @ offsetof(struct SaveBlock1, playerParty)
-	.4byte 0x00000009 @ offsetof(struct SaveBlock2, specialSaveWarpFlags)
-	.4byte 0x0000000a @ offsetof(struct SaveBlock2, playerTrainerId)
-	.4byte 0x00000000 @ offsetof(struct SaveBlock2, playerName)
-	.4byte 0x00000008 @ offsetof(struct SaveBlock2, playerGender)
-	.4byte 0x00000ca8 @ offsetof(struct SaveBlock2, frontier.challengeStatus)
-	.4byte 0x00000ca8 @ offsetof(struct SaveBlock2, frontier.challengeStatus)
-	.4byte 0x000031c7 @ offsetof(struct SaveBlock1, externalEventFlags)
-	.4byte 0x000031b3 @ offsetof(struct SaveBlock1, externalEventData)
-	.4byte 0x00000000
-
-	.4byte gBaseStats
-	.4byte gAbilityNames
-	.4byte gAbilityDescriptionPointers
-	.4byte gItems
-	.4byte gBattleMoves
-	.4byte gBallSpriteSheets
-	.4byte gBallSpritePalettes
-
-	.4byte 0x000000a8 @ offsetof(struct SaveBlock2, gcnLinkFlags)
-	.4byte 0x00000864 @ ?
-	.4byte 0x0000089b @ ?
-
-	.byte 0x1e, 0x1e, 0x10, 0x40
-
-	.4byte 0x0000322e @ offsetof(struct SaveBlock1, ? part-way into mysteryGift)
-	.4byte 0x00000498 @ offsetof(struct SaveBlock1, pcItems)
-	.4byte 0x000031a8 @ offsetof(struct SaveBlock1, giftRibbons)
-	.4byte 0x000031f8 @ offsetof(struct SaveBlock1, enigmaBerry)
-	.4byte 0x00000034 @ offsetof(struct SaveBlock1, mapView)
-	.4byte 0x00000000
-	.4byte 0x00000000
-
-	.arm
 	.align 2, 0
 	.global Init
 Init: @ 8000204
diff --git a/src/rom_header.s b/src/rom_header.s
new file mode 100644
index 000000000..5ed45124d
--- /dev/null
+++ b/src/rom_header.s
@@ -0,0 +1,63 @@
+@ Note: ROM header data is empty space here.
+@       It's populated by gbafix using data provided in the Makefile. 
+
+	.global Start
+Start: @ 8000000
+	b Init
+
+	.global RomHeaderNintendoLogo
+RomHeaderNintendoLogo:
+	.space 156
+
+RomHeaderGameTitle:
+	.space 12
+
+	.global RomHeaderGameCode
+RomHeaderGameCode:
+	.space 4
+
+RomHeaderMakerCode:
+	.space 2
+
+RomHeaderMagic:
+	.byte 0
+
+RomHeaderMainUnitCode:
+	.byte 0
+
+RomHeaderDeviceType:
+	.byte 0
+
+RomHeaderReserved1:
+	.space 7
+
+	.global RomHeaderSoftwareVersion
+RomHeaderSoftwareVersion:
+	.byte 0
+
+RomHeaderChecksum:
+	.byte 0
+
+RomHeaderReserved2:
+	.space 2
+
+@ 80000C0
+    .word 0
+
+    .global GPIOPortData
+GPIOPortData: @ 80000C4
+    .2byte 0
+
+    .global GPIOPortDirection
+GPIOPortDirection: @ 80000C6
+    .2byte 0
+
+    .global GPIOPortReadEnable
+GPIOPortReadEnable: @ 80000C8
+    .2byte 0
+
+@ 80000CA
+    .2byte 0
+
+@ 80000CC
+    .space 0x34
diff --git a/src/rom_header_gf.c b/src/rom_header_gf.c
new file mode 100644
index 000000000..782a05c75
--- /dev/null
+++ b/src/rom_header_gf.c
@@ -0,0 +1,165 @@
+#include "global.h"
+#include "data.h"
+#include "pokemon_icon.h"
+#include "decoration.h"
+#include "battle_main.h"
+#include "item.h"
+#include "pokeball.h"
+
+struct GFRomHeader
+{
+    u32 version;
+    u32 language;
+    u8 gameName[32];
+    const struct CompressedSpriteSheet * monFrontPics;
+    const struct CompressedSpriteSheet * monBackPics;
+    const struct CompressedSpritePalette * monNormalPalettes;
+    const struct CompressedSpritePalette * monShinyPalettes;
+    const u8 * const * monIcons;
+    const u8 * monIconPaletteIds;
+    const struct SpritePalette * monIconPalettes;
+    const u8 (* monSpeciesNames)[];
+    const u8 (* moveNames)[];
+    const struct Decoration * decorations;
+    u32 flagsOffset;
+    u32 varsOffset;
+    u32 pokedexOffset;
+    u32 seen1Offset;
+    u32 seen2Offset;
+    u32 pokedexVar;
+    u32 pokedexFlag;
+    u32 mysteryEventFlag;
+    u32 pokedexCount;
+    u8 unk1;
+    u8 unk2;
+    u8 unk3;
+    u8 unk4;
+    u8 unk5;
+    u8 unk6;
+    u8 unk7;
+    u8 unk8;
+    u8 unk9;
+    u8 unk10;
+    u8 unk11;
+    u8 unk12;
+    u8 unk13;
+    u8 unk14;
+    u8 unk15;
+    u8 unk16;
+    u8 unk17;
+    u32 saveBlock2Size;
+    u32 saveBlock1Size;
+    u32 partyCountOffset;
+    u32 partyOffset;
+    u32 warpFlagsOffset;
+    u32 trainerIdOffset;
+    u32 playerNameOffset;
+    u32 playerGenderOffset;
+    u32 frontierStatusOffset;
+    u32 frontierStatusOffset2;
+    u32 externalEventFlagsOffset;
+    u32 externalEventDataOffset;
+    u32 unk18;
+    const struct BaseStats * baseStats;
+    const u8 (* abilityNames)[];
+    const u8 * const * abilityDescriptions;
+    const struct Item * items;
+    const struct BattleMove * moves;
+    const struct CompressedSpriteSheet * ballGfx;
+    const struct CompressedSpritePalette * ballPalettes;
+    u32 gcnLinkFlagsOffset;
+    u32 gameClearFlag;
+    u32 ribbonFlag;
+    u8 bagCountItems;
+    u8 bagCountKeyItems;
+    u8 bagCountPokeballs;
+    u8 bagCountTMHMs;
+    u8 bagCountBerries;
+    u8 pcItemsCount;
+    u32 pcItemsOffset;
+    u32 giftRibbonsOffset;
+    u32 enigmaBerryOffset;
+    u32 mapViewOffset;
+    u32 unk19;
+    u32 unk20;
+};
+
+// This seems to need to be in the text section for some reason.
+// To avoid a changed section attributes warning it's put in a special .text.consts section.
+__attribute__((section(".text.consts")))
+static const struct GFRomHeader sGFRomHeader = {
+    .version = GAME_VERSION,
+    .language = GAME_LANGUAGE,
+    .gameName = "pokemon emerald version",
+    .monFrontPics = gMonFrontPicTable,
+    .monBackPics = gMonBackPicTable,
+    .monNormalPalettes = gMonPaletteTable,
+    .monShinyPalettes = gMonShinyPaletteTable,
+    .monIcons = gMonIconTable,
+    .monIconPaletteIds = gMonIconPaletteIndices,
+    .monIconPalettes = gMonIconPaletteTable,
+    .monSpeciesNames = gSpeciesNames,
+    .moveNames = gMoveNames,
+    .decorations = gDecorations,
+    .flagsOffset = offsetof(struct SaveBlock1, flags),
+    .varsOffset = offsetof(struct SaveBlock1, vars),
+    .pokedexOffset = offsetof(struct SaveBlock2, pokedex),
+    .seen1Offset = offsetof(struct SaveBlock1, seen1),
+    .seen2Offset = offsetof(struct SaveBlock1, seen2),
+    .pokedexVar = VAR_NATIONAL_DEX - VARS_START,
+    .pokedexFlag = FLAG_RECEIVED_POKEDEX_FROM_BIRCH,
+    .mysteryEventFlag = FLAG_SYS_MYSTERY_EVENT_ENABLE,
+    .pokedexCount = NATIONAL_DEX_COUNT,
+    .unk1 = 0x07,
+    .unk2 = 0x0a,
+    .unk3 = 0x0a,
+    .unk4 = 0x0a,
+    .unk5 = 0x0c,
+    .unk6 = 0x0c,
+    .unk7 = 0x06,
+    .unk8 = 0x0c,
+    .unk9 = 0x06,
+    .unk10 = 0x10,
+    .unk11 = 0x12,
+    .unk12 = 0x0c,
+    .unk13 = 0x0f,
+    .unk14 = 0x0b,
+    .unk15 = 0x01,
+    .unk16 = 0x08,
+    .unk17 = 0x0c,
+    .saveBlock2Size = sizeof(struct SaveBlock2),
+    .saveBlock1Size = sizeof(struct SaveBlock1),
+    .partyCountOffset = offsetof(struct SaveBlock1, playerPartyCount),
+    .partyOffset = offsetof(struct SaveBlock1, playerParty),
+    .warpFlagsOffset = offsetof(struct SaveBlock2, specialSaveWarpFlags),
+    .trainerIdOffset = offsetof(struct SaveBlock2, playerTrainerId),
+    .playerNameOffset = offsetof(struct SaveBlock2, playerName),
+    .playerGenderOffset = offsetof(struct SaveBlock2, playerGender),
+    .frontierStatusOffset = offsetof(struct SaveBlock2, frontier.challengeStatus),
+    .frontierStatusOffset2 = offsetof(struct SaveBlock2, frontier.challengeStatus),
+    .externalEventFlagsOffset = offsetof(struct SaveBlock1, externalEventFlags),
+    .externalEventDataOffset = offsetof(struct SaveBlock1, externalEventData),
+    .unk18 = 0x00000000,
+    .baseStats = gBaseStats,
+    .abilityNames = gAbilityNames,
+    .abilityDescriptions = gAbilityDescriptionPointers,
+    .items = gItems,
+    .moves = gBattleMoves,
+    .ballGfx = gBallSpriteSheets,
+    .ballPalettes = gBallSpritePalettes,
+    .gcnLinkFlagsOffset = offsetof(struct SaveBlock2, gcnLinkFlags),
+    .gameClearFlag = FLAG_SYS_GAME_CLEAR,
+    .ribbonFlag = FLAG_SYS_RIBBON_GET,
+    .bagCountItems = BAG_ITEMS_COUNT,
+    .bagCountKeyItems = BAG_KEYITEMS_COUNT,
+    .bagCountPokeballs = BAG_POKEBALLS_COUNT,
+    .bagCountTMHMs = BAG_TMHM_COUNT,
+    .bagCountBerries = BAG_BERRIES_COUNT,
+    .pcItemsCount = PC_ITEMS_COUNT,
+    .pcItemsOffset = offsetof(struct SaveBlock1, pcItems),
+    .giftRibbonsOffset = offsetof(struct SaveBlock1, giftRibbons),
+    .enigmaBerryOffset = offsetof(struct SaveBlock1, enigmaBerry),
+    .mapViewOffset = offsetof(struct SaveBlock1, mapView),
+    .unk19 = 0x00000000,
+    .unk20 = 0x00000000, // 0xFFFFFFFF in FRLG
+};