Decompiled sub_81C756C

Also discovered a constant that may be useful for future decompiling.
Comments were added in the asm that references the constant.

asm/pokenav.s

@@ -5,55 +5,6 @@
 
 	.text
 
-	thumb_func_start sub_81C756C
-sub_81C756C: @ 81C756C
-	push {r4-r6,lr}
-	ldr r1, =0xfffe7960
-	adds r6, r0, r1
-	bl sub_81C75F4
-	ldr r5, =gUnknown_0861F3EC
-	lsls r0, r6, 3
-	subs r0, r6
-	lsls r4, r0, 2
-	adds r0, r4, r5
-	ldr r0, [r0]
-	bl _call_via_r0
-	cmp r0, 0
-	beq _081C75CC
-	adds r0, r5, 0
-	adds r0, 0x8
-	adds r0, r4, r0
-	ldr r0, [r0]
-	bl _call_via_r0
-	cmp r0, 0
-	beq _081C75CC
-	adds r0, r5, 0
-	adds r0, 0xC
-	adds r0, r4, r0
-	ldr r0, [r0]
-	adds r1, r5, 0
-	adds r1, 0x10
-	adds r1, r4, r1
-	ldr r1, [r1]
-	bl sub_81C7834
-	ldr r0, =gUnknown_0203CF40
-	ldr r1, [r0]
-	adds r0, r5, 0x4
-	adds r0, r4, r0
-	ldr r0, [r0]
-	str r0, [r1]
-	str r6, [r1, 0x4]
-	movs r0, 0x1
-	b _081C75CE
-	.pool
-_081C75CC:
-	movs r0, 0
-_081C75CE:
-	pop {r4-r6}
-	pop {r1}
-	bx r1
-	thumb_func_end sub_81C756C
-
 	thumb_func_start sub_81C75D4
 sub_81C75D4: @ 81C75D4
 	push {lr}
@@ -9441,7 +9392,7 @@ sub_81CBE50: @ 81CBE50
 	movs r0, 0x9
 	bl GetGameStat
 	adds r1, r0, 0
-	ldr r0, =0x0001869f
+	ldr r0, =0x0001869f @ Note to decompiler: See UNKNOWN_OFFSET
 	cmp r1, r0
 	ble _081CBE68
 	adds r1, r0, 0

asm/rom_8011DC0.s

@@ -27181,7 +27181,7 @@ sub_8024700: @ 8024700
 	adds r0, r5, 0
 	bl sub_8024668
 	adds r1, r0, r4
-	ldr r2, =0x0001869f
+	ldr r2, =0x0001869f @ Note to decompiler: See UNKNOWN_OFFSET
 	cmp r1, r2
 	bhi _08024730
 	adds r0, r5, 0

src/pokedex.c

@@ -4036,7 +4036,7 @@ void sub_80C0460(u16 weight, u8 left, u8 top)
     lsls r2, 24\n\
     lsrs r2, 24\n\
     str r2, [sp, 0x10]\n\
-    ldr r5, =0x000186a0\n\
+    ldr r5, =0x000186a0 @ Note to decompiler: See UNKNOWN_OFFSET\n\
     muls r0, r5\n\
     ldr r1, =0x000011b8\n\
     bl __divsi3\n\
@@ -4070,7 +4070,7 @@ _080C04C0:\n\
     mov r8, r1\n\
     movs r6, 0x1\n\
 _080C04C6:\n\
-    ldr r1, =0x000186a0\n\
+    ldr r1, =0x000186a0 @ Note to decompiler: See UNKNOWN_OFFSET\n\
     adds r0, r7, 0\n\
     bl __umodsi3\n\
     adds r7, r0, 0\n\

src/pokenav_main.c

@@ -7,8 +7,10 @@
 #include "palette.h"
 #include "pokemon_storage_system.h"
 
+#define UNKNOWN_OFFSET 100000
+
 struct UnknownStruct_0203CF40 {
-	u32 field0;
+	u32 (*field0)(void);
 	u32 field4;
 	u16 field8;
 	u32 fieldC;
@@ -17,7 +19,7 @@ struct UnknownStruct_0203CF40 {
 };
 
 struct UnknownStruct_0861F3EC {
-	void (*data[7])(void);
+	u32 (*data[7])(void);
 };
 
 extern struct UnknownStruct_0203CF40 *gUnknown_0203CF40;
@@ -29,13 +31,15 @@ extern void sub_81C76C4(void);
 extern void sub_81C7710(void);
 extern void sub_81C7850(u32 a0);
 extern void sub_81C9430(void);
-extern u32 sub_81C756C(u32 a0);
+extern void sub_81C75F4(void);
+extern void sub_81C7834(u32 (*a0)(void), u32(*a1)(void));
 extern u32 sub_81C76FC(void);
 extern u32 sub_81C786C(void);
 extern u32 sub_81C75E0(void);
 extern u32 sub_81C75D4(void);
 extern u32 sub_81C7738(void);
 
+bool32 sub_81C756C(u32 a0);
 u32 AnyMonHasRibbon(void);
 void sub_81C7334(void);
 void sub_81C71E4(u8 a0);
@@ -220,7 +224,7 @@ void sub_81C7360(struct UnknownStruct_0203CF40 *a0) {
 	a0->field8 = 0;
 	a0->field4 = 0;
 	a0->fieldC = AnyMonHasRibbon();
-	a0->field0 = 0;
+	a0->field0 = NULL;
 }
 
 bool32 AnyMonHasRibbon() {
@@ -278,7 +282,7 @@ void sub_81C742C(u8 taskId) {
 		if (sub_81C76FC()) {
 			break;
 		}
-		sub_81C756C(0x186a0);
+		sub_81C756C(UNKNOWN_OFFSET);
 		dataPtr[0] = 4;
 		break;
 	case 2:
@@ -291,7 +295,7 @@ void sub_81C742C(u8 taskId) {
 		if (v1 == -1) {
 			sub_81C7710();
 			dataPtr[0] = 5;
-		} else if (v1 > 0x1869F) {
+		} else if (v1 >= UNKNOWN_OFFSET) {
 			gUnknown_0861F3EC[gUnknown_0203CF40->field4].data[6]();
 			gUnknown_0861F3EC[gUnknown_0203CF40->field4].data[5]();
 			if (sub_81C756C(v1)) {
@@ -324,4 +328,21 @@ void sub_81C742C(u8 taskId) {
 			}
 		}
 	}
+}
+
+bool32 sub_81C756C(u32 a0) {
+	u32 index;
+
+	index = a0 - UNKNOWN_OFFSET;
+	sub_81C75F4();
+	if (!gUnknown_0861F3EC[index].data[0]()) {
+		return FALSE;
+	}
+	if (!gUnknown_0861F3EC[index].data[2]()) {
+		return FALSE;
+	}
+	sub_81C7834(gUnknown_0861F3EC[index].data[3], gUnknown_0861F3EC[index].data[4]);
+	gUnknown_0203CF40->field0 = gUnknown_0861F3EC[index].data[1];
+	gUnknown_0203CF40->field4 = index;
+	return TRUE;
 }