Use labels instead of constants for HRAM

Use explicit ldh instruction to access HRAM locations, don't rely on optimizing ld

home/copy_tilemap.asm

@@ -1,35 +1,35 @@
 LoadTileMapToTempTileMap::
 ; Load wTileMap into wTempTileMap
-	ld a, [rSVBK]
+	ldh a, [rSVBK]
 	push af
 	ld a, BANK(wTempTileMap)
-	ld [rSVBK], a
+	ldh [rSVBK], a
 	hlcoord 0, 0
 	decoord 0, 0, wTempTileMap
 	ld bc, wTileMapEnd - wTileMap
 	call CopyBytes
 	pop af
-	ld [rSVBK], a
+	ldh [rSVBK], a
 	ret
 
 Call_LoadTempTileMapToTileMap::
 	xor a
-	ld [hBGMapMode], a
+	ldh [hBGMapMode], a
 	call LoadTempTileMapToTileMap
 	ld a, 1
-	ld [hBGMapMode], a
+	ldh [hBGMapMode], a
 	ret
 
 LoadTempTileMapToTileMap::
 ; Load wTempTileMap into wTileMap
-	ld a, [rSVBK]
+	ldh a, [rSVBK]
 	push af
 	ld a, BANK(wTempTileMap)
-	ld [rSVBK], a
+	ldh [rSVBK], a
 	hlcoord 0, 0, wTempTileMap
 	decoord 0, 0
 	ld bc, wTileMapEnd - wTileMap
 	call CopyBytes
 	pop af
-	ld [rSVBK], a
+	ldh [rSVBK], a
 	ret