From 6448563ede13d51682cbf1988a2072291f3b3df0 Mon Sep 17 00:00:00 2001
From: scnorton <scnorton@biociphers.org>
Date: Wed, 6 Sep 2017 16:14:55 -0400
Subject: [PATCH] unref_sub_808D77C

---
 asm/battle_setup.s         |  4 +-
 asm/bike.s                 |  4 +-
 asm/decoration.s           | 18 ++++-----
 asm/field_camera.s         |  6 +--
 asm/field_control_avatar.s | 28 ++++++-------
 asm/field_map_obj.s        | 82 +-------------------------------------
 asm/field_tasks.s          |  2 +-
 asm/fieldmap.s             | 30 +++++++-------
 asm/fldeff_80F9BCC.s       |  2 +-
 asm/fldeff_teleport.s      |  2 +-
 asm/item_use.s             | 10 ++---
 asm/pokemon_3.s            |  2 +-
 asm/region_map.s           |  8 ++--
 asm/rom4.s                 | 56 +++++++++++++-------------
 asm/rom6.s                 | 14 +++----
 asm/rom_80C6FA0.s          |  8 ++--
 asm/rom_818CFC8.s          | 22 +++++-----
 asm/rom_81BE66C.s          | 24 +++++------
 asm/script.s               |  2 +-
 asm/secret_base.s          | 12 +++---
 asm/shop.s                 |  2 +-
 asm/tileset.s              |  4 +-
 asm/tv.s                   | 14 +++----
 asm/weather.s              |  2 +-
 asm/wild_encounter.s       | 10 ++---
 include/rom_818CFC8.h      | 11 +++++
 include/rom_81BE66C.h      | 10 +++++
 src/field_map_obj.c        | 35 ++++++++++++++++
 sym_ewram.txt              |  2 +-
 29 files changed, 202 insertions(+), 224 deletions(-)
 create mode 100644 include/rom_818CFC8.h
 create mode 100644 include/rom_81BE66C.h

diff --git a/asm/battle_setup.s b/asm/battle_setup.s
index a075614642..a4b143703b 100644
--- a/asm/battle_setup.s
+++ b/asm/battle_setup.s
@@ -678,7 +678,7 @@ _080B0C16:
 	lsls r0, 24
 	cmp r0, 0
 	bne _080B0D18
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	subs r0, 0x1
 	cmp r0, 0x8
@@ -830,7 +830,7 @@ _080B0D54:
 	lsls r0, 24
 	cmp r0, 0
 	bne _080B0D7C
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x4
 	beq _080B0D78
diff --git a/asm/bike.s b/asm/bike.s
index 00db73ca1c..22d52c0fa0 100644
--- a/asm/bike.s
+++ b/asm/bike.s
@@ -1775,7 +1775,7 @@ sub_8119EF0: @ 8119EF0
 	lsls r0, 24
 	cmp r0, 0
 	bne _08119F08
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x8
 	bne _08119F10
@@ -2173,7 +2173,7 @@ IsRunningDisallowed: @ 811A1DC
 	push {lr}
 	lsls r0, 24
 	lsrs r2, r0, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x1A]
 	movs r0, 0x4
 	ands r0, r1
diff --git a/asm/decoration.s b/asm/decoration.s
index 9d228be38e..26449f85d6 100644
--- a/asm/decoration.s
+++ b/asm/decoration.s
@@ -2472,7 +2472,7 @@ sub_8127E18: @ 8127E18
 	push {r5-r7}
 	sub sp, 0x4
 	movs r6, 0
-	ldr r7, =gUnknown_02037318
+	ldr r7, =gMapHeader
 	ldr r0, =gSpecialVar_0x8005
 	mov r8, r0
 	ldr r1, =gSpecialVar_0x8006
@@ -2500,7 +2500,7 @@ _08127E34:
 	ldrh r0, [r0, 0x14]
 	cmp r0, r5
 	beq _08127E82
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r3, [r0, 0x4]
 	ldrb r6, [r3]
 	adds r4, r5, 0
@@ -3938,7 +3938,7 @@ _08128A64:
 	ldrh r1, [r0, 0x22]
 	adds r1, 0x2
 	strh r1, [r0, 0x22]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x14]
 	cmp r0, 0x56
 	bne _08128A84
@@ -4282,7 +4282,7 @@ _08128D48:
 	movs r0, 0x2
 	ldrsh r1, [r2, r0]
 	subs r1, 0x7
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0, 0x4]
 	cmp r1, r0
@@ -4316,7 +4316,7 @@ _08128D82:
 	ldrsh r0, [r2, r4]
 	adds r1, r0
 	subs r1, 0x8
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0]
 	cmp r1, r0
@@ -5559,7 +5559,7 @@ _08129744:
 	ldrb r0, [r4]
 	bl sub_81296EC
 	movs r1, 0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0x4]
 	ldrb r2, [r0]
 	cmp r1, r2
@@ -5591,7 +5591,7 @@ _08129796:
 sub_81297AC: @ 81297AC
 	push {r4-r6,lr}
 	movs r2, 0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0x4]
 	ldrb r1, [r0]
 	cmp r2, r1
@@ -5684,7 +5684,7 @@ _08129846:
 _0812985E:
 	adds r0, r4, 0x7
 	add r0, r8
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldr r3, [r1]
 	ldr r1, [sp]
 	subs r2, r1, r6
@@ -5817,7 +5817,7 @@ _08129968:
 	adds r0, r5, 0
 	adds r1, r4, 0
 	bl DisplayItemMessageOnField
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x14]
 	cmp r0, 0x56
 	bne _08129994
diff --git a/asm/field_camera.s b/asm/field_camera.s
index 450e961747..cead2954c9 100644
--- a/asm/field_camera.s
+++ b/asm/field_camera.s
@@ -135,7 +135,7 @@ DrawWholeMapView: @ 8089C34
 	ldrsh r0, [r1, r2]
 	movs r2, 0x2
 	ldrsh r1, [r1, r2]
-	ldr r2, =gUnknown_02037318
+	ldr r2, =gMapHeader
 	ldr r2, [r2]
 	bl DrawWholeMapViewInternal
 	ldr r1, =gUnknown_03000E20
@@ -225,7 +225,7 @@ RedrawMapSlicesForCameraUpdate: @ 8089CE4
 	adds r5, r0, 0
 	adds r6, r1, 0
 	adds r7, r2, 0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r4, [r0]
 	cmp r6, 0
 	ble _08089CFC
@@ -476,7 +476,7 @@ CurrentMapDrawMetatileAt: @ 8089EA0
 	adds r1, r0, 0
 	cmp r1, 0
 	blt _08089ECC
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	lsls r1, 16
 	lsrs r1, 16
diff --git a/asm/field_control_avatar.s b/asm/field_control_avatar.s
index 3d989e9e4e..85009cc5b8 100644
--- a/asm/field_control_avatar.s
+++ b/asm/field_control_avatar.s
@@ -704,7 +704,7 @@ TryGetInvisibleMapObjectScript: @ 809C458
 	push {r4,r5,lr}
 	lsls r2, 24
 	lsrs r5, r2, 24
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldrh r1, [r0]
 	subs r1, 0x7
 	lsls r1, 16
@@ -1194,7 +1194,7 @@ sub_809C89C: @ 809C89C
 	lsls r0, 24
 	cmp r0, 0
 	beq _0809C8D4
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x5
 	bne _0809C8D4
@@ -1264,7 +1264,7 @@ _0809C930:
 	thumb_func_start mapheader_trigger_activate_at__run_now
 mapheader_trigger_activate_at__run_now: @ 809C938
 	push {r4,lr}
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldrh r1, [r0]
 	subs r1, 0x7
 	lsls r1, 16
@@ -1545,7 +1545,7 @@ overworld_poison_timer_set: @ 809CB80
 	thumb_func_start overworld_poison_step
 overworld_poison_step: @ 809CB94
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x9
 	beq _0809CBD4
@@ -1639,7 +1639,7 @@ mapheader_run_first_tag2_script_list_match_conditionally: @ 809CC38
 	lsrs r4, 16
 	lsls r5, 24
 	lsrs r5, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	mov r8, r0
 	adds r1, r7, 0
 	bl map_warp_check_packed
@@ -1683,7 +1683,7 @@ sub_809CC9C: @ 809CC9C
 	adds r6, r0, 0
 	lsls r1, 16
 	lsrs r5, r1, 16
-	ldr r7, =gUnknown_02037318
+	ldr r7, =gMapHeader
 	adds r0, r7, 0
 	adds r1, r6, 0
 	bl map_warp_check_packed
@@ -1958,7 +1958,7 @@ sub_809CEB0: @ 809CEB0
 	adds r4, r0, 0
 	cmp r4, 0
 	bne _0809CEE8
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0x4]
 	ldr r5, [r0, 0x8]
 	b _0809CF0E
@@ -1976,7 +1976,7 @@ _0809CEF0:
 	adds r5, r0, 0
 	b _0809CF0E
 _0809CF00:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0x4]
 	lsls r2, r4, 24
 	asrs r1, r2, 21
@@ -2053,7 +2053,7 @@ map_warp_consider_2_to_inside: @ 809CF78
 	lsrs r0, 24
 	cmp r0, 0x1
 	bne _0809CFB0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r1, [r0, 0x4]
 	adds r0, r5, 0
 	bl sub_80E9668
@@ -2067,7 +2067,7 @@ _0809CFB0:
 	lsrs r0, 24
 	cmp r0, 0x1
 	bne _0809CFFC
-	ldr r6, =gUnknown_02037318
+	ldr r6, =gMapHeader
 	adds r0, r6, 0
 	adds r1, r5, 0
 	bl map_warp_check_packed
@@ -2243,7 +2243,7 @@ _0809D0E4:
 	thumb_func_start sub_809D0F4
 sub_809D0F4: @ 809D0F4
 	push {r4,lr}
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldrh r1, [r0]
 	subs r1, 0x7
 	lsls r1, 16
@@ -2316,7 +2316,7 @@ dive_warp: @ 809D16C
 	adds r4, r0, 0
 	lsls r1, 16
 	lsrs r5, r1, 16
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x5
 	bne _0809D1A4
@@ -2389,7 +2389,7 @@ sub_809D1E8: @ 809D1E8
 	bl MapGridGetMetatileBehaviorAt
 	lsls r0, 24
 	lsrs r5, r0, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x5
 	bne _0809D244
@@ -2491,7 +2491,7 @@ sub_809D2BC: @ 809D2BC
 	movs r2, 0x2
 	ldrsh r1, [r4, r2]
 	bl MapGridGetMetatileBehaviorAt
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	adds r0, r4, 0
 	mov r1, sp
 	bl map_warp_check_packed
diff --git a/asm/field_map_obj.s b/asm/field_map_obj.s
index 8afd73a019..31b5224678 100644
--- a/asm/field_map_obj.s
+++ b/asm/field_map_obj.s
@@ -5,84 +5,6 @@
 
 	.text
 
-	thumb_func_start sub_808D77C
-sub_808D77C: @ 808D77C
-	push {r4-r7,lr}
-	mov r7, r8
-	push {r7}
-	lsls r0, 24
-	lsrs r0, 24
-	mov r8, r0
-	ldr r4, =gUnknown_02037318
-	ldr r0, [r4, 0x4]
-	cmp r0, 0
-	beq _0808D7FE
-	bl InBattlePyramid
-	lsls r0, 24
-	cmp r0, 0
-	beq _0808D7A8
-	bl sub_81AAA40
-	lsls r0, 24
-	lsrs r6, r0, 24
-	b _0808D7CA
-	.pool
-_0808D7A8:
-	bl InTrainerHill
-	cmp r0, 0
-	beq _0808D7C6
-	movs r6, 0x2
-	b _0808D7CA
-_0808D7B4:
-	ldr r0, [r7]
-	ldrb r1, [r0, 0x5]
-	ldrb r2, [r0, 0x4]
-	adds r0, r4, 0
-	bl InitFieldObjectStateFromTemplate
-	lsls r0, 24
-	lsrs r0, 24
-	b _0808D800
-_0808D7C6:
-	ldr r0, [r4, 0x4]
-	ldrb r6, [r0]
-_0808D7CA:
-	movs r5, 0
-	cmp r5, r6
-	bcs _0808D7FE
-	ldr r7, =gSaveBlock1Ptr
-_0808D7D2:
-	lsls r0, r5, 1
-	adds r0, r5
-	lsls r0, 3
-	movs r1, 0xC7
-	lsls r1, 4
-	adds r0, r1
-	ldr r1, [r7]
-	adds r4, r1, r0
-	ldrb r0, [r4]
-	cmp r0, r8
-	bne _0808D7F4
-	ldrh r0, [r4, 0x14]
-	bl FlagGet
-	lsls r0, 24
-	cmp r0, 0
-	beq _0808D7B4
-_0808D7F4:
-	adds r0, r5, 0x1
-	lsls r0, 24
-	lsrs r5, r0, 24
-	cmp r5, r6
-	bcc _0808D7D2
-_0808D7FE:
-	movs r0, 0x10
-_0808D800:
-	pop {r3}
-	mov r8, r3
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	.pool
-	thumb_func_end sub_808D77C
-
 	thumb_func_start GetAvailableFieldObjectSlot
 @ bool8 GetAvailableFieldObjectSlot(u16 localId, u8 mapId, u8 mapGroupId, u8 *fieldObjectId)
 GetAvailableFieldObjectSlot: @ 808D810
@@ -1066,7 +988,7 @@ SpawnFieldObjectsInView: @ 808DF80
 	lsls r1, 16
 	lsrs r1, 16
 	str r1, [sp, 0x8]
-	ldr r5, =gUnknown_02037318
+	ldr r5, =gMapHeader
 	ldr r0, [r5, 0x4]
 	cmp r0, 0
 	beq _0808E078
@@ -3478,7 +3400,7 @@ GetFieldObjectTemplateByLocalIdAndMap: @ 808F128
 	movs r0, 0xC7
 	lsls r0, 4
 	adds r1, r0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0x4]
 	b _0808F16C
 	.pool
diff --git a/asm/field_tasks.s b/asm/field_tasks.s
index 5f9a49f94b..fb99bbc0e7 100644
--- a/asm/field_tasks.s
+++ b/asm/field_tasks.s
@@ -1201,7 +1201,7 @@ sub_809E1C8: @ 809E1C8
 	mov r7, r9
 	mov r6, r8
 	push {r6,r7}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r1, [r0]
 	mov r9, r1
diff --git a/asm/fieldmap.s b/asm/fieldmap.s
index 037133d1e9..d2416248fa 100644
--- a/asm/fieldmap.s
+++ b/asm/fieldmap.s
@@ -19,7 +19,7 @@ mapconnection_get_mapheader: @ 8087D44
 	thumb_func_start not_trainer_hill_battle_pyramid
 not_trainer_hill_battle_pyramid: @ 8087D54
 	push {r4,lr}
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	adds r0, r4, 0
 	bl mapheader_copy_mapdata_with_padding
 	ldr r0, [r4, 0x4]
@@ -34,7 +34,7 @@ not_trainer_hill_battle_pyramid: @ 8087D54
 	thumb_func_start sub_8087D74
 sub_8087D74: @ 8087D74
 	push {r4,lr}
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	adds r0, r4, 0
 	bl mapheader_copy_mapdata_with_padding
 	movs r0, 0
@@ -554,7 +554,7 @@ MapGridGetZCoordAt: @ 8088144
 	b _08088196
 	.pool
 _08088174:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r3, [r0]
 	adds r1, r2, 0x1
 	movs r2, 0x1
@@ -613,7 +613,7 @@ MapGridIsImpassableAt: @ 80881B0
 	b _08088202
 	.pool
 _080881E0:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r3, [r0]
 	adds r1, r2, 0x1
 	movs r2, 0x1
@@ -675,7 +675,7 @@ MapGridGetMetatileIdAt: @ 8088224
 	b _08088278
 	.pool
 _08088254:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r3, [r0]
 	adds r1, r5, 0x1
 	movs r2, 0x1
@@ -702,7 +702,7 @@ _08088278:
 	b _080882B0
 	.pool
 _0808828C:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r3, [r0]
 	adds r1, r5, 0x1
 	movs r2, 0x1
@@ -839,7 +839,7 @@ GetBehaviorByMetatileId: @ 8088370
 	ldr r0, =0x000001ff
 	cmp r2, r0
 	bhi _08088394
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0, 0x10]
 	ldr r1, [r0, 0x10]
@@ -854,7 +854,7 @@ _08088394:
 	b _080883B6
 	.pool
 _080883A4:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0, 0x14]
 	ldr r1, [r0, 0x10]
@@ -1029,7 +1029,7 @@ _080884EC:
 	mov r9, r1
 	cmp r6, r0
 	bne _08088508
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0, 0x4]
 	subs r0, 0x1
@@ -1104,7 +1104,7 @@ _08088574:
 	asrs r1, r2, 16
 	bl sub_80D423C
 _08088584:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0, 0x4]
 	subs r0, 0x1
@@ -1282,7 +1282,7 @@ GetMapBorderIdAt: @ 808869C
 	b _08088700
 	.pool
 _080886D8:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r3, [r0]
 	adds r1, r4, 0x1
 	movs r2, 0x1
@@ -1607,7 +1607,7 @@ sub_8088950: @ 8088950
 	mov r8, r2
 	lsls r0, 24
 	lsrs r6, r0, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0xC]
 	ldr r7, [r0]
 	ldr r4, [r0, 0x4]
@@ -1664,7 +1664,7 @@ sub_80889A8: @ 80889A8
 	blt _08088A00
 	cmp r4, 0x2
 	bgt _080889E0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r1, [r0]
 	ldr r0, [r2]
@@ -1676,7 +1676,7 @@ sub_80889A8: @ 80889A8
 _080889E0:
 	cmp r6, 0x4
 	bgt _08088A00
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r1, [r0, 0x4]
 	ldr r0, [r2]
@@ -1792,7 +1792,7 @@ sub_8088A8C: @ 8088A8C
 	mov r8, r0
 	lsls r1, 16
 	lsrs r1, 16
-	ldr r2, =gUnknown_02037318
+	ldr r2, =gMapHeader
 	ldr r0, [r2, 0xC]
 	cmp r0, 0
 	bne _08088AB4
diff --git a/asm/fldeff_80F9BCC.s b/asm/fldeff_80F9BCC.s
index 465f64db35..d5e620c774 100644
--- a/asm/fldeff_80F9BCC.s
+++ b/asm/fldeff_80F9BCC.s
@@ -468,7 +468,7 @@ _080F9F54:
 sub_80F9F5C: @ 80F9F5C
 	push {lr}
 	ldr r0, =gUnknown_0203AB40
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldr r1, [r1, 0x4]
 	bl sub_80E9608
 	bl sub_80E8B6C
diff --git a/asm/fldeff_teleport.s b/asm/fldeff_teleport.s
index bbca5095fb..0e14cd4183 100644
--- a/asm/fldeff_teleport.s
+++ b/asm/fldeff_teleport.s
@@ -8,7 +8,7 @@
 	thumb_func_start SetUpFieldMove_Teleport
 SetUpFieldMove_Teleport: @ 817C8BC
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	bl is_light_level_1_2_3_or_6
 	lsls r0, 24
diff --git a/asm/item_use.s b/asm/item_use.s
index cd1c382157..8d3c0ce41d 100644
--- a/asm/item_use.s
+++ b/asm/item_use.s
@@ -553,7 +553,7 @@ ItemUseOnFieldCB_Itemfinder: @ 80FD4B8
 	push {r4,lr}
 	lsls r0, 24
 	lsrs r4, r0, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0x4]
 	adds r1, r4, 0
 	bl ItemfinderCheckForHiddenItems
@@ -906,7 +906,7 @@ _080FD76C:
 	subs r0, r5, r0
 	lsls r0, 16
 	lsrs r1, r0, 16
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0, 0x4]
 	b _080FD79E
@@ -918,7 +918,7 @@ _080FD784:
 	adds r0, r5
 	b _080FD798
 _080FD78E:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0]
 	adds r0, 0x7
@@ -964,7 +964,7 @@ sub_80FD7C8: @ 80FD7C8
 	lsls r0, 24
 	lsrs r0, 24
 	str r0, [sp, 0x4]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r1, [r0]
 	ldr r0, [r1]
 	adds r0, 0x7
@@ -2288,7 +2288,7 @@ re_escape_rope: @ 80FE2D8
 	thumb_func_start sub_80FE314
 sub_80FE314: @ 80FE314
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x1A]
 	movs r0, 0x2
 	ands r0, r1
diff --git a/asm/pokemon_3.s b/asm/pokemon_3.s
index ca77a64a4f..22c72f443c 100644
--- a/asm/pokemon_3.s
+++ b/asm/pokemon_3.s
@@ -5733,7 +5733,7 @@ _0806EA7C:
 	mov r8, r2
 	movs r7, 0x50
 _0806EAC6:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	movs r0, 0xD2
 	lsls r0, 1
diff --git a/asm/region_map.s b/asm/region_map.s
index 7169818132..7a0a5dae36 100644
--- a/asm/region_map.s
+++ b/asm/region_map.s
@@ -1571,7 +1571,7 @@ _08123904:
 _08123928:
 	ldr r4, =gUnknown_0203A144
 	ldr r0, [r4]
-	ldr r3, =gUnknown_02037318
+	ldr r3, =gMapHeader
 	ldrb r1, [r3, 0x14]
 	movs r2, 0
 	strh r1, [r0]
@@ -1599,7 +1599,7 @@ _08123956:
 	b _08123ABE
 	.pool
 _0812396C:
-	ldr r2, =gUnknown_02037318
+	ldr r2, =gMapHeader
 	ldrb r1, [r2, 0x1A]
 	movs r0, 0x2
 	ands r0, r1
@@ -1685,7 +1685,7 @@ _081239E4:
 _08123A28:
 	ldr r4, =gUnknown_0203A144
 	ldr r0, [r4]
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldrb r1, [r1, 0x14]
 	strh r1, [r0]
 	cmp r1, 0x57
@@ -2811,7 +2811,7 @@ sub_8124288: @ 8124288
 	str r0, [sp, 0x10]
 	ldr r0, =SpriteCallbackDummy
 	str r0, [sp, 0x14]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x14]
 	bl sub_8124668
 	cmp r0, 0
diff --git a/asm/rom4.s b/asm/rom4.s
index 10d6076832..b6a5c0fa06 100644
--- a/asm/rom4.s
+++ b/asm/rom4.s
@@ -278,7 +278,7 @@ CopyFieldObjectTemplatesToSav1: @ 8084894
 	ldr r2, =0x05000180
 	mov r0, sp
 	bl CpuSet
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r2, [r0, 0x4]
 	ldr r0, [r2, 0x4]
 	ldr r1, [r5]
@@ -302,7 +302,7 @@ CopyFieldObjectTemplatesToSav1: @ 8084894
 @ void CopyFieldObjectTemplateCoordsToSav1()
 CopyFieldObjectTemplateCoordsToSav1: @ 80848E0
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r1, [r0, 0x4]
 	ldr r0, =gSaveBlock1Ptr
 	ldr r0, [r0]
@@ -393,7 +393,7 @@ _08084978:
 mapdata_load_assets_to_gpu_and_full_redraw: @ 8084980
 	push {r4,lr}
 	bl move_tilemap_camera_to_upper_left_corner
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldr r0, [r4]
 	bl copy_map_tileset1_tileset2_to_vram
 	ldr r0, [r4]
@@ -571,7 +571,7 @@ warp1_get_mapheader: @ 8084AA8
 set_current_map_header_from_sav1_save_old_name: @ 8084ACC
 	push {r4-r6,lr}
 	ldr r1, =gUnknown_020322FC
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldrb r0, [r4, 0x14]
 	strh r0, [r1]
 	ldr r5, =gSaveBlock1Ptr
@@ -607,7 +607,7 @@ set_current_map_header_from_sav1_save_old_name: @ 8084ACC
 	thumb_func_start set_current_map_header_from_sav1
 set_current_map_header_from_sav1: @ 8084B1C
 	push {r4,r5,lr}
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldr r0, =gSaveBlock1Ptr
 	ldr r1, [r0]
 	movs r0, 0x4
@@ -646,7 +646,7 @@ update_camera_pos_from_warpid: @ 8084B5C
 	adds r4, r0, 0
 	cmp r1, 0
 	blt _08084B94
-	ldr r3, =gUnknown_02037318
+	ldr r3, =gMapHeader
 	ldr r0, [r3, 0x4]
 	ldrb r5, [r0, 0x1]
 	cmp r1, r5
@@ -680,7 +680,7 @@ _08084B94:
 	b _08084BCC
 _08084BB0:
 	ldr r3, [r4]
-	ldr r2, =gUnknown_02037318
+	ldr r2, =gMapHeader
 	ldr r0, [r2]
 	ldr r0, [r0]
 	lsrs r1, r0, 31
@@ -1232,7 +1232,7 @@ sub_8084FC0: @ 8084FC0
 	push {r4,lr}
 	lsls r0, 24
 	lsrs r4, r0, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0xC]
 	ldr r3, [r0]
 	ldr r1, [r0, 0x4]
@@ -1366,7 +1366,7 @@ mliX_load_map: @ 8085098
 	str r3, [sp]
 	adds r2, r3, 0
 	bl warp1_set
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldrb r0, [r4, 0x14]
 	cmp r0, 0x3A
 	beq _080850C8
@@ -1407,7 +1407,7 @@ _08085116:
 	bl sub_80AEE20
 	bl wild_encounter_reset_coro_args
 	bl mapheader_run_script_with_tag_x5
-	ldr r2, =gUnknown_02037318
+	ldr r2, =gMapHeader
 	ldrb r0, [r2, 0x14]
 	cmp r0, 0x3A
 	bne _0808514C
@@ -1436,7 +1436,7 @@ mli0_load_map: @ 8085160
 	ands r0, r1
 	cmp r0, 0
 	bne _080851A2
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	ldr r0, =0x00000169
 	cmp r1, r0
@@ -1453,7 +1453,7 @@ _08085190:
 _0808519E:
 	bl CopyFieldObjectTemplatesToSav1
 _080851A2:
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldrb r0, [r4, 0x17]
 	bl is_light_level_1_2_3_5_or_6
 	lsls r0, 24
@@ -1802,7 +1802,7 @@ cur_mapdata_block_role_at_screen_center_acc_to_sav1: @ 8085450
 	thumb_func_start sav1_map_is_biking_allowed
 sav1_map_is_biking_allowed: @ 8085474
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x1A]
 	movs r0, 0x1
 	ands r0, r1
@@ -1821,7 +1821,7 @@ _0808548E:
 	thumb_func_start update_sav1_flash_used_on_map
 update_sav1_flash_used_on_map: @ 8085494
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x15]
 	cmp r1, 0
 	bne _080854B0
@@ -1897,7 +1897,7 @@ sub_8085524: @ 8085524
 	ldr r1, [r1]
 	strh r0, [r1, 0x32]
 	bl get_mapdata_header
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	str r0, [r1]
 	pop {r0}
 	bx r0
@@ -3471,7 +3471,7 @@ sub_80861E8: @ 80861E8
 	thumb_func_start sub_8086204
 sub_8086204: @ 8086204
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x1A]
 	movs r0, 0xF8
 	ands r0, r1
@@ -3507,7 +3507,7 @@ _0808624A:
 	bl GetCurrentTrainerHillMapId
 	lsls r0, 24
 	lsrs r4, r0, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	ldr r0, =0x00000169
 	cmp r1, r0
@@ -3528,7 +3528,7 @@ _0808628A:
 	bl sub_809757C
 	bl sub_809E7B0
 	bl sub_8084788
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	ldr r0, =0x00000169
 	cmp r1, r0
@@ -3739,13 +3739,13 @@ _08086492:
 	bl move_tilemap_camera_to_upper_left_corner
 	b _08086506
 _08086498:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl copy_map_tileset1_to_vram
 	b _08086506
 	.pool
 _080864A8:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl copy_map_tileset2_to_vram
 	b _08086506
@@ -3756,7 +3756,7 @@ _080864B8:
 	lsrs r0, 24
 	cmp r0, 0x1
 	beq _08086512
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl apply_map_tileset1_tileset2_palette
 	b _08086506
@@ -3858,13 +3858,13 @@ _080865A6:
 	bl move_tilemap_camera_to_upper_left_corner
 	b _08086622
 _080865AC:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl copy_map_tileset1_to_vram
 	b _08086622
 	.pool
 _080865BC:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl copy_map_tileset2_to_vram
 	b _08086622
@@ -3875,7 +3875,7 @@ _080865CC:
 	lsrs r0, 24
 	cmp r0, 0x1
 	beq _0808662E
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl apply_map_tileset1_tileset2_palette
 	b _08086622
@@ -3887,7 +3887,7 @@ _080865EE:
 	bl cur_mapheader_run_tileset_funcs_after_some_cpuset
 	b _08086622
 _080865F4:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x1A]
 	movs r0, 0xF8
 	ands r0, r1
@@ -4027,13 +4027,13 @@ _0808671E:
 	bl move_tilemap_camera_to_upper_left_corner
 	b _08086792
 _08086724:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl copy_map_tileset1_to_vram
 	b _08086792
 	.pool
 _08086734:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl copy_map_tileset2_to_vram
 	b _08086792
@@ -4044,7 +4044,7 @@ _08086744:
 	lsrs r0, 24
 	cmp r0, 0x1
 	beq _080867A8
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	bl apply_map_tileset1_tileset2_palette
 	b _08086792
diff --git a/asm/rom6.s b/asm/rom6.s
index a0f23d7203..ef2d27110a 100644
--- a/asm/rom6.s
+++ b/asm/rom6.s
@@ -88,7 +88,7 @@ task08_080C9820: @ 813549C
 	cmp r0, 0
 	beq _0813551E
 _081354D2:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x5
 	bne _08135504
@@ -3346,7 +3346,7 @@ sub_81370FC: @ 81370FC
 	b _08137152
 	.pool
 _08137134:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x15]
 	cmp r0, 0x1
 	bne _08137170
@@ -5213,7 +5213,7 @@ is_tile_that_overrides_player_control: @ 81380D8
 	lsls r0, 24
 	cmp r0, 0
 	beq _0813810A
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x1
 	blt _0813810A
@@ -5250,7 +5250,7 @@ sub_8138120: @ 8138120
 	lsls r0, 24
 	cmp r0, 0
 	beq _08138152
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x1
 	blt _08138152
@@ -5287,7 +5287,7 @@ sub_8138168: @ 8138168
 	lsls r0, 24
 	cmp r0, 0
 	beq _0813819A
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x1
 	blt _0813819A
@@ -5324,7 +5324,7 @@ sub_81381B0: @ 81381B0
 	lsls r0, 24
 	cmp r0, 0
 	beq _081381E2
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x1
 	blt _081381E2
@@ -5361,7 +5361,7 @@ sub_81381F8: @ 81381F8
 	lsls r0, 24
 	cmp r0, 0
 	beq _0813822A
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x1
 	blt _0813822A
diff --git a/asm/rom_80C6FA0.s b/asm/rom_80C6FA0.s
index 17399a49d6..04d4c29f4a 100644
--- a/asm/rom_80C6FA0.s
+++ b/asm/rom_80C6FA0.s
@@ -26359,7 +26359,7 @@ ShowMapNamePopUpWindow: @ 80D49B0
 	lsls r0, 24
 	cmp r0, 0
 	beq _080D4A08
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	movs r0, 0xBD
 	lsls r0, 1
@@ -26391,7 +26391,7 @@ _080D49F2:
 _080D4A08:
 	mov r4, sp
 	adds r4, 0xF
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x14]
 	adds r0, r4, 0
 	movs r2, 0
@@ -26610,7 +26610,7 @@ LoadMapNamePopUpWindowBg: @ 80D4BE0
 	bl GetMapNamePopUpWindowId
 	lsls r0, 24
 	lsrs r5, r0, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x14]
 	cmp r1, 0x57
 	bls _080D4C0A
@@ -26647,7 +26647,7 @@ _080D4C0A:
 	bl CallWindowFunction
 	adds r0, r5, 0
 	bl PutWindowTilemap
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x16]
 	cmp r0, 0xE
 	bne _080D4C6C
diff --git a/asm/rom_818CFC8.s b/asm/rom_818CFC8.s
index 37e0802be4..b78cbccdde 100644
--- a/asm/rom_818CFC8.s
+++ b/asm/rom_818CFC8.s
@@ -16833,7 +16833,7 @@ _08195ED2:
 	thumb_func_start sub_8195ED8
 sub_8195ED8: @ 8195ED8
 	push {r4,lr}
-	ldr r4, =gUnknown_02037318
+	ldr r4, =gMapHeader
 	ldrb r0, [r4, 0x17]
 	bl is_light_level_1_2_3_or_6
 	lsls r0, 24
@@ -16857,7 +16857,7 @@ sub_8195ED8: @ 8195ED8
 	cmp r0, 0
 	beq _08195F30
 _08195F0E:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x14]
 	cmp r0, 0x38
 	bne _08195F38
@@ -16932,7 +16932,7 @@ sub_8195F68: @ 8195F68
 	bl sub_8196844
 	adds r4, r0, 0
 	bl sub_819672C
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	lsls r0, 16
 	lsrs r0, 16
 	ldrb r1, [r1, 0x14]
@@ -17938,7 +17938,7 @@ sub_81967AC: @ 81967AC
 	beq _081967EC
 	adds r0, r5, 0
 	bl sub_819672C
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	lsls r0, 16
 	lsrs r0, 16
 	ldrb r1, [r1, 0x14]
@@ -25773,7 +25773,7 @@ _0819A3D6:
 	b _0819A43C
 	.pool
 _0819A404:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r1, [r0, 0x14]
 	adds r0, r5, 0
 	bl sub_81245DC
@@ -49364,7 +49364,7 @@ _081A6BEE:
 sub_81A6BF4: @ 81A6BF4
 	push {lr}
 	movs r2, 0
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldr r3, =0xfffffea5
 	adds r0, r3, 0
 	ldrh r1, [r1, 0x12]
@@ -51948,7 +51948,7 @@ sub_81A8090: @ 81A8090
 InBattlePike: @ 81A80A8
 	push {lr}
 	movs r2, 0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	ldr r3, =0xfffffea1
 	adds r0, r1, r3
@@ -55513,7 +55513,7 @@ sub_81A9E28: @ 81A9E28
 	thumb_func_start InBattlePyramid
 InBattlePyramid: @ 81A9E40
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	ldr r0, =0x00000169
 	cmp r1, r0
@@ -55539,7 +55539,7 @@ _081A9E66:
 sub_81A9E6C: @ 81A9E6C
 	push {lr}
 	movs r2, 0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	ldr r0, =0x00000169
 	cmp r1, r0
@@ -77653,7 +77653,7 @@ _081B5880:
 	thumb_func_start sub_81B5884
 sub_81B5884: @ 81B5884
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	bl is_light_level_1_2_3_or_6
 	lsls r0, 24
@@ -85842,7 +85842,7 @@ sub_81B9E88: @ 81B9E88
 sub_81B9E94: @ 81B9E94
 	push {lr}
 	movs r2, 0
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldrb r0, [r1, 0x14]
 	cmp r0, 0x8
 	bne _081B9EB2
diff --git a/asm/rom_81BE66C.s b/asm/rom_81BE66C.s
index c1b5f91422..ad83d6402a 100644
--- a/asm/rom_81BE66C.s
+++ b/asm/rom_81BE66C.s
@@ -21069,7 +21069,7 @@ sub_81C98D4: @ 81C98D4
 _081C98D8:
 	adds r0, r4, 0
 	bl sub_81CB0C8
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	lsls r0, 24
 	lsrs r0, 24
 	ldrb r1, [r1, 0x14]
@@ -23981,7 +23981,7 @@ sub_81CAF78: @ 81CAF78
 	adds r4, r0, 0
 	movs r0, 0
 	strb r0, [r6]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	bl is_light_level_1_2_3_or_6
 	lsls r0, 24
@@ -24309,7 +24309,7 @@ sub_81CB1D0: @ 81CB1D0
 	bne _081CB218
 	adds r0, r1, 0
 	bl sub_81CAEA4
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	lsls r0, 16
 	lsrs r0, 16
 	ldrb r1, [r1, 0x14]
@@ -24330,7 +24330,7 @@ _081CB218:
 	bne _081CB258
 	adds r0, r1, 0
 	bl sub_81CAEA4
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	lsls r0, 16
 	lsrs r0, 16
 	ldrb r1, [r1, 0x14]
@@ -26717,7 +26717,7 @@ _081CC4F0:
 	b _081CC51A
 	.pool
 _081CC4F8:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x14]
 	bl sub_8124668
 	str r0, [r4, 0xC]
@@ -44923,7 +44923,7 @@ _081D54EE:
 
 	thumb_func_start sub_81D5520
 sub_81D5520: @ 81D5520
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x12]
 	adds r0, 0x61
 	lsls r0, 24
@@ -45134,7 +45134,7 @@ sub_81D56B0: @ 81D56B0
 	ldr r0, =0x00000eec
 	bl AllocZeroed
 	str r0, [r4]
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldrb r1, [r1, 0x12]
 	adds r1, 0x61
 	strb r1, [r0]
@@ -46192,7 +46192,7 @@ _081D5FE6:
 	lsls r0, 24
 	lsrs r0, 24
 	mov r9, r0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r2, [r0, 0xC]
 	ldr r1, =gUnknown_03005DC0
@@ -46261,7 +46261,7 @@ _081D605E:
 	thumb_func_start InTrainerHill
 InTrainerHill: @ 81D6074
 	push {lr}
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldr r2, =0xfffffe61
 	adds r0, r2, 0
 	ldrh r1, [r1, 0x12]
@@ -46283,7 +46283,7 @@ _081D608C:
 @ u8 GetCurrentTrainerHillMapId()
 GetCurrentTrainerHillMapId: @ 81D609C
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r2, [r0, 0x12]
 	ldr r0, =0x0000019f
 	cmp r2, r0
@@ -46335,7 +46335,7 @@ _081D60F8:
 	thumb_func_start sub_81D6100
 sub_81D6100: @ 81D6100
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	ldr r0, =0x000001a3
 	movs r2, 0
@@ -46369,7 +46369,7 @@ sub_81D6134: @ 81D6134
 	lsrs r0, 24
 	cmp r0, 0x1
 	bne _081D614C
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0, 0x4]
 	ldr r0, [r0, 0x8]
 	adds r0, 0x8
diff --git a/asm/script.s b/asm/script.s
index e625b56254..b55b27ecac 100644
--- a/asm/script.s
+++ b/asm/script.s
@@ -442,7 +442,7 @@ mapheader_get_tagged_pointer: @ 8098F88
 	push {lr}
 	lsls r0, 24
 	lsrs r1, r0, 24
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r2, [r0, 0x8]
 	cmp r2, 0
 	beq _08098F9C
diff --git a/asm/secret_base.s b/asm/secret_base.s
index 06ccaa9da7..99e15fe0fa 100644
--- a/asm/secret_base.s
+++ b/asm/secret_base.s
@@ -251,7 +251,7 @@ sub_80E8CB0: @ 80E8CB0
 	lsls r2, 16
 	lsrs r2, 16
 	mov r10, r2
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	mov r8, r0
 	movs r0, 0
@@ -502,7 +502,7 @@ _080E8E32:
 	movs r1, 0x2
 	strb r1, [r0]
 	ldr r0, =0x00004026
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldrb r1, [r1, 0x14]
 	bl VarSet
 	pop {r3}
@@ -727,7 +727,7 @@ sub_80E9068: @ 80E9068
 	thumb_func_start sub_80E909C
 sub_80E909C: @ 80E909C
 	push {lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x17]
 	cmp r0, 0x9
 	bne _080E90C0
@@ -1104,7 +1104,7 @@ _080E93BE:
 	b _080E9554
 _080E93D4:
 	movs r5, 0
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r3, [r0, 0x4]
 	ldrb r4, [r3]
 	mov r9, r0
@@ -1294,7 +1294,7 @@ _080E9562:
 sub_80E9578: @ 80E9578
 	push {r4-r6,lr}
 	movs r5, 0
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldr r0, [r1, 0x4]
 	ldrb r0, [r0]
 	cmp r5, r0
@@ -1936,7 +1936,7 @@ sub_80E9AC0: @ 80E9AC0
 	thumb_func_start sub_80E9AD0
 sub_80E9AD0: @ 80E9AD0
 	push {r4-r7,lr}
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r4, [r0, 0x4]
 	movs r6, 0
 	b _080E9B62
diff --git a/asm/shop.s b/asm/shop.s
index 1e86ea6455..d8074a41e2 100644
--- a/asm/shop.s
+++ b/asm/shop.s
@@ -1293,7 +1293,7 @@ BuyMenuDrawMapBg: @ 80E0584
 	mov r5, r8
 	push {r5-r7}
 	sub sp, 0x4
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	mov r9, r0
 	mov r4, sp
diff --git a/asm/tileset.s b/asm/tileset.s
index 97c1e78c21..0605c76219 100644
--- a/asm/tileset.s
+++ b/asm/tileset.s
@@ -182,7 +182,7 @@ cur_mapheader_run_tileset1_func: @ 80A0AA8
 	ldr r1, =gUnknown_03000F40
 	movs r0, 0
 	str r0, [r1]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0, 0x10]
 	cmp r0, 0
@@ -208,7 +208,7 @@ cur_mapheader_run_tileset2_func: @ 80A0AE4
 	ldr r1, =gUnknown_03000F44
 	movs r0, 0
 	str r0, [r1]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldr r0, [r0]
 	ldr r0, [r0, 0x14]
 	cmp r0, 0
diff --git a/asm/tv.s b/asm/tv.s
index ccf232dd08..7c80b85a68 100644
--- a/asm/tv.s
+++ b/asm/tv.s
@@ -742,7 +742,7 @@ GabbyAndTyAfterInterview: @ 80EC448
 	orrs r0, r2
 	strb r0, [r1]
 	ldr r0, [r5]
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldrb r1, [r1, 0x14]
 	ldr r2, =0x00002bac
 	adds r0, r2
@@ -1221,7 +1221,7 @@ _080EC8CA:
 	strh r0, [r4, 0x4]
 	ldrh r0, [r1, 0x6]
 	strh r0, [r4, 0x8]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x14]
 	strb r0, [r4, 0xA]
 	pop {r4}
@@ -1309,7 +1309,7 @@ _080EC940:
 	mov r1, r8
 	ldrb r0, [r1]
 	strb r0, [r4, 0x11]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x14]
 	strb r0, [r4, 0x12]
 	adds r0, r4, 0
@@ -2311,7 +2311,7 @@ SaveRecordedItemPurchasesForTVShow: @ 80ED238
 	movs r0, 0x16
 	strb r0, [r5]
 	strb r4, [r5, 0x1]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x14]
 	strb r0, [r5, 0x12]
 	movs r4, 0
@@ -3333,7 +3333,7 @@ _080EDBCC:
 	bl sub_80C0844
 _080EDBD2:
 	strh r0, [r4, 0x2]
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldrb r0, [r1, 0x14]
 	strb r0, [r4, 0x7]
 	ldrh r0, [r1, 0x12]
@@ -3491,7 +3491,7 @@ sub_80EDCE8: @ 80EDCE8
 	ldr r0, =gSpecialVar_0x8005
 	ldrh r0, [r0]
 	strh r0, [r4, 0x2]
-	ldr r1, =gUnknown_02037318
+	ldr r1, =gMapHeader
 	ldrb r0, [r1, 0x14]
 	strb r0, [r4, 0x4]
 	ldrh r0, [r1, 0x12]
@@ -4049,7 +4049,7 @@ _080EE1B6:
 	strb r1, [r4, 0x1]
 	movs r5, 0
 	ldr r6, =gUnknown_03005D10
-	ldr r3, =gUnknown_02037318
+	ldr r3, =gMapHeader
 	ldr r7, =gSaveBlock2Ptr
 	adds r2, r6, 0
 	adds r2, 0x36
diff --git a/asm/weather.s b/asm/weather.s
index 7bb483e4a3..769d77c6b4 100644
--- a/asm/weather.s
+++ b/asm/weather.s
@@ -7544,7 +7544,7 @@ sub_80AEDBC: @ 80AEDBC
 	ldr r0, [r4]
 	adds r0, 0x2E
 	ldrb r5, [r0]
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrb r0, [r0, 0x16]
 	bl sub_80AEEE8
 	ldr r1, [r4]
diff --git a/asm/wild_encounter.s b/asm/wild_encounter.s
index c2e57a3f3f..79222e3a9e 100644
--- a/asm/wild_encounter.s
+++ b/asm/wild_encounter.s
@@ -46,7 +46,7 @@ sub_80B48C4: @ 80B48C4
 	ldrh r5, [r2]
 	cmp r5, r9
 	bhi _080B496E
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	mov r10, r0
 _080B4906:
 	movs r4, 0
@@ -956,7 +956,7 @@ _080B4FBA:
 	cmp r0, 0
 	beq _080B5000
 _080B4FE0:
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	movs r0, 0xB3
 	lsls r0, 1
@@ -1191,7 +1191,7 @@ _080B519A:
 	lsrs r0, 24
 	cmp r0, 0x1
 	bne _080B51E8
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	ldr r0, =0x00000169
 	cmp r1, r0
@@ -1319,7 +1319,7 @@ _080B52A6:
 	ldr r0, =0x0000ffff
 	cmp r5, r0
 	bne _080B539C
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	movs r0, 0xB3
 	lsls r0, 1
@@ -1658,7 +1658,7 @@ sub_80B5578: @ 80B5578
 	ldr r0, =0x0000ffff
 	cmp r4, r0
 	bne _080B562C
-	ldr r0, =gUnknown_02037318
+	ldr r0, =gMapHeader
 	ldrh r1, [r0, 0x12]
 	movs r0, 0xB3
 	lsls r0, 1
diff --git a/include/rom_818CFC8.h b/include/rom_818CFC8.h
new file mode 100644
index 0000000000..9b6f968938
--- /dev/null
+++ b/include/rom_818CFC8.h
@@ -0,0 +1,11 @@
+//
+// Created by Scott Norton on 9/6/17.
+//
+
+#ifndef POKEEMERALD_ROM_818CFC8_H
+#define POKEEMERALD_ROM_818CFC8_H
+
+bool8 InBattlePyramid(void);
+u8 sub_81AAA40(void);
+
+#endif //POKEEMERALD_ROM_818CFC8_H
diff --git a/include/rom_81BE66C.h b/include/rom_81BE66C.h
new file mode 100644
index 0000000000..d92c500d69
--- /dev/null
+++ b/include/rom_81BE66C.h
@@ -0,0 +1,10 @@
+//
+// Created by Scott Norton on 9/6/17.
+//
+
+#ifndef POKEEMERALD_ROM_81BE66C_H
+#define POKEEMERALD_ROM_81BE66C_H
+
+bool32 InTrainerHill(void);
+
+#endif //POKEEMERALD_ROM_81BE66C_H
diff --git a/src/field_map_obj.c b/src/field_map_obj.c
index b97d5c0dc9..b33cf06698 100644
--- a/src/field_map_obj.c
+++ b/src/field_map_obj.c
@@ -4,6 +4,9 @@
 #include "sprite.h"
 #include "rom4.h"
 #include "field_player_avatar.h"
+#include "event_data.h"
+#include "rom_818CFC8.h"
+#include "rom_81BE66C.h"
 #include "field_map_obj.h"
 
 // Static struct declarations
@@ -352,3 +355,35 @@ __attribute__((naked)) u8 InitFieldObjectStateFromTemplate(struct MapObjectTempl
                 ".pool");
 }
 #endif
+
+u8 unref_sub_808D77C(u8 localId)
+{
+    u8 i;
+    u8 nObjects;
+    struct MapObjectTemplate *template;
+
+    if (gMapHeader.events != NULL)
+    {
+        if (InBattlePyramid())
+        {
+            nObjects = sub_81AAA40();
+        }
+        else if (InTrainerHill())
+        {
+            nObjects = 2;
+        }
+        else
+        {
+            nObjects = gMapHeader.events->mapObjectCount;
+        }
+        for (i = 0; i < nObjects; i ++)
+        {
+            template = &gSaveBlock1Ptr->mapObjectTemplates[i];
+            if (template->localId == localId && !FlagGet(template->flagId))
+            {
+                return InitFieldObjectStateFromTemplate(template, gSaveBlock1Ptr->location.mapNum, gSaveBlock1Ptr->location.mapGroup);
+            }
+        }
+    }
+    return ARRAY_COUNT(gMapObjects);
+}
diff --git a/sym_ewram.txt b/sym_ewram.txt
index 71b6ffeae1..df8f32f6a8 100644
--- a/sym_ewram.txt
+++ b/sym_ewram.txt
@@ -746,7 +746,7 @@ gUnknown_02032308: @ 2032308
 gUnknown_02032318: @ 2032318
 	.space 0x5000
 
-gUnknown_02037318: @ 2037318
+gMapHeader: @ 2037318
 	.space 0x1C
 
 gUnknown_02037334: @ 2037334